Peer Reviewed REFERENCES:
1: MDI ClinicalStudies from AroundTheUSA Boston,Massachusetts 2012
How Successful are Small Diameter Implants: A Literature Review 2012
Keyvan Sohrabi Ammar Mushantat Shahrokh Esfandiari Jocelyne Feine
Keyvan Sohrabi, Deptartment of Oral Health Policy and Epidemiology,
Harvard School of Dental Medicine, Boston, MA, Clin. Oral Impl. Res. 0, 2012 / 1–11
© 2012 John Wiley & Sons A/S
Edentulism is an important issue and will remain so due to high numbers of edentate individuals worldwide. For many years, complete dentures have been the only treatment option for this population. Implant overdentures have been shown to have many advantages over conventional complete dentures. However, although dissatisfied with their mandibular dentures, some edentate elders are reluctant to undergo even simple implant treatment due to factors such as cost and fear of surgery. To address these obstacles, this paper reports on a review of small- diameter implant (SDI) studies that were performed in the last two decades. The aim of this study is to (i) determine the survival of narrow diameter implants, (ii) determine whether survival is dependent on whether these implants are placed using a flap or flapless approach, and (ii) determine whether there is a relationship between length and implant survival in SDIs.
In this review, studies were included that (i) involve implants with 3.5 mm diameter or less, (ii) have a randomized clinical trial, retrospective or prospective cohort design with human subjects, (iii) provide a follow up duration of at least 5 months following implant placement, (iv) include data on the survival rate of the implants.
Forty one studies meeting the above criteria were published between 1993 and 2011 using SDIs from a variety of companies and surface characteristics with diameters of 1.8 mm to 3.5 mm and lengths of 8 mm to 18 mm. A total of 10,093 SDIs were inserted in approximately 2762 patients. Twenty-six studies involved flap reflection techniques for implant placement, six studies used a flapless technique and two studies used both techniques; in the remaining studies, the technique was not specified. Follow up duration varied from 5 months to over 9 years. The survival rate reported in all screened studies was over 90%, including eight studies in which a 100% survival rate was reported. In 22 studies, the reported survival rate ranged from 95% to 99.9%. Failure was reported most often in short SDIs (less than or equal 13 mm) (n = 88) compared to longer ones (more than 13 mm).
Survival rates reported for SDI are SIMILAR to those reported for STANDARD width implants.
These survival rates did not appear to differ between studies that used flapless and flap reflection techniques. The failure rate appeared to be higher in shorter SDIs than in longer ones in the studies in which the length of the failed implants was reported.
SDIs could be considered for use with FIXED fixed restorations and mandibular overdentures, since their SUCCESS RATE appears to be COMPARABLE to that of regular diameter implants. They might also be an efficient, low-cost solution for elders who wish to reduce problems with denture instability.
2: MDI ClinicalStudies from AroundTheUSA Willimantic ,Connecticut 2015
Mini Implants Supporting Fixed Partial Dentures in the Posterior Mandible: A Retrospective (2015)
Dennis Flanagan, DDS, MSc
Journal of Oral Implantology e138 Vol. XLI/No. Four/2015
Small-diameter, or mini dental implants have been successfully used to support removable and FIXED oral prostheses.
These implants impart about twice the per-square-millimeter force on the supporting bone and this should be addressed during treatment planning. In the posterior jaws, bite forces are of a higher magnitude than in the anterior jaws and may induce an overload of the supporting bone and failure of the osseointegration.
Thus there should not be occlusal contact in functional excursions that induce off axial loads.
The cases presented herein demonstrate that mini dental implants may be used successfully to support fixed partial dentures in mandibular sites in highly selected patients.
Mini or small-diameter dental implants (,3.2 mm) have been used successfully for many years.1,2
Probably most of these have been used to retain removable partial and complete dentures.
Nevertheless, many clinicians use mini implants to support fixed complete and partial dentures.
There have been no long-term randomized blinded controlled trials of this treatment or a failure rate established.
Many patients have site conditions, or medical or psychological conditions that preclude the use of standard-diameter implants (3.25 mm).
These patients may not be able to undergo augmentation procedures or they may object to a larger metallic foreign body being placed in the jaw.
Economics may be an issue as well.
FIGURE 1. The crowns and fixed partial dentures were fabricated with a very narrow occlusal table to minimize off-axial loads.
FIGURE 2. A recent radiograph demonstrates little or no bone loss. No graduated operative radiographs were made so bone loss measurements could not be made.
Mini implants may be placed in many of these patients without substantial augmentation procedures and surgical trauma may be much less.
In addition, the cost of mini implant surgery is substantially less than standard diameter implants.
Some clinicians may feel comfortable using mini implants to support fixed partial dentures in the posterior mandible.
The posterior mandible has a higher occlusal load magnitude with multidirectional cyclic loading. This subjects the bone-implant- prosthesis complex to more severe loading conditions than in anterior sites. This may affect the longevity of the treatment outcome so treatment planning for this parameter is of paramount importance.
The object of this effort is to demonstrate that in highly selected cases with appropriate prosthetic design and osseous support, mini implants may be successfully used to support fixed partial dentures in the mandible.
All patients had medical, economic, psychological, and or attenuated site reasons that made standard diameter implants not an option for treatment.
All implants were small diameter ranging from 2.0-3.0 mm manufactured by Imtec (Irvine, Calif), IntraLock (Boca Raton, Fla), or Biohorizons (Birmingham, Ala).
All prosthetics were single crowns, 2, 3, or 4 splinted prosthetic units fabricated in porcelain fused to noble alloy (PFM) by a commercial dental laboratory (York Dental Lab, Branford, Conn).
All implants were placed in healed, partially edentulous sites. Prosthetic design included a very narrow, rounded, occlusal table, less than premolar dimensions, with absolutely no occlusal contact in functional excursions (Figures 1 and 2). Esthetic compromises were accepted preoperatively by all patients.
All prostheses were made with a flat narrow rounded occlusal table with little artistic anatomical recreation by the technician.
The laboratory technician was instructed to place 3 coats of die separator to ensure a passive fit and account for the expansion.
Forty-nine patients in 50 cases were treated. Most implants were successfully functioning for a documented average of 5.5 years
FIGURE 1. The crowns and fixed partial dentures were fabricated with a very narrow occlusal table to minimize off-axial loads.
FIGURE 2. A recent radiograph demonstrates little or no bone loss.
recemented with insoluble resin modified glass ionomer cement (FujiCEM, 3M
The percutaneous portion of mini implants is much LESS than standard sized implants and thus presents less of an opportunity for coronal epithelial attachment issues.
The circumference (pi 3 diameter) of a 2.5-mm mini implant is 7.85 mm as compared to a standard-sized implant (4.0 mm) at 12.56 mm, which is 160% longer.
This presents much LESS of an opportunity for PERI-IMPLANTITIS, but the rate of peri-implantitis in mini implants has not yet been reported.
- These cases demonstrate that many patients with conditions that may preclude standard diameter implant treatment, may be treated with mini implant-supported FIXED partial dentures. This is a highly selective and exclusive group of patients that may qualify for such treatment.
- Particular care should be given to bone density of the site, observation of a 4-month healing time, flapless placement, use of longer implants than 10 mm, treatment of any existing periodontitis, choice of an insoluble luting cement, exclusion of occlusal contact in excursions, and very slow seating rotation with intermissions and water irrigation during seating.
- As a retrospective case series this work is a lower level of credibility. More study of occlusal design, materials, and bone resistance physiology is needed to develop this treatment concept.
3: MDI ClinicalStudies from AroundTheUSA Willimantic ,Connecticut 2008
IMMEDIATE PLACEMENT OF MULTIPLE MINI DENTAL IMPLANTS INTO FRESH EXTRACTION SITES: A CASE REPORT 2008
Dennis Flanagan, DDS
Journal of Oral Implantology Vol. XXXIV/No. Two/2008
This case report discusses the immediate placement of 3 mini dental implants into 3 fresh extraction sockets. The implants were used to support a SPLINTED FIXED PARTIAL DENTURE.
Immediately placing implants of a very small diameter into fresh extraction sockets to support a FIXED PARTIAL DENTURE is possible.
Some implant sites cannot accept standard-sized implants because of length or width deficiencies.
Very small diameter implants may be able to support FIXED prostheses in these sites.
Immediate placement of implants into fresh extraction sockets may preserve bone and speed treatment.
Immediate placement of multiple mini dental implants into fresh extraction sockets can support a medium- span FIXED partial denture.
4: MDI ClinicalStudies from AroundTheUSA Willimantic ,Connecticut 2011
The Mini Dental Implant in Fixed and Removable Prosthetics: A Review : A REVIEW 2011
Dennis Flanagan, DDS1* Andrea Mascolo, DDS2
Journal of Oral Implantology Vol. XXXVII/Special Issue
Mini implants may be IMMEDIATELY LOADED in the appropriate osseous situations and may provide an alternative treatment if OSSEOUS CONDITIONS preclude a standard sized implant approach.2,3,11–14
In situations where there is an INADEQUATE INTERDENTAL SPACE, REDUCED INTEROCCLUSAL SPACE ,convergent adjacent tooth roots or close proximity of adjacent tooth roots or narrow atrophic osseous contour, mini implants may be appropriate.1–
Mini implants are consistent with the trend towards MINIMALLY INVASIVE DENTISTRY. Minimally invasive dentistry has been brought to the forefront by some practitioners and may be applied to implant dentistry where appropriate.
The esthetic zone is wherever the patient deems it to be.
Patient expectations may be unrealistic and acceptance of potentially smaller prosthetic coronas may be objectionable to certain patients.
TWO mini implants may be used for certain mandibular tooth-bound MOLAR SITES to accept a splinted crown restoration.3,22
GENERALLY, these sites have shortened site lengths where a standard diameter implant may not fit with adequate tooth-to-implant spacing.
TWO (2) mini implants can resist axial forces.
However, rounded and narrow prosthetic teeth may be required to present a small occlusal table to minimize off-axial forces.2,3
Single mini implants may support single crown restorations (Figures 7 and 8). Sites with short interdental space (less than 5 mm), such as maxillary lateral and mandibular incisors, and sites where tooth movement has imposed on the site length or the local anatomy is diminutive may accept a single mini implant.3,23 Anterior sites may be more appropriate because of lower occlusal forces.
When mini implants are SPLINTED in FIXED partial or complete dentures, the adjacent implants are ANCHORED to each other, DISSIPATING FORCE and MINIMIZING the potential for implant MICROMOVEMENT .
However, cement loosening in one abutment may cause the fixed bridge to rotate slightly on the cemented abutment and lose osseointegration. An astute clinician may choose to definitively cement only mini-implant–supported prostheses to prevent this complication.
The most retentive metal-to-metal cements are the RESINS and resin-modified glass ionomers.
MINI DENTAL IMPLANTS may be appropriate to retain removable prostheses and support FIXED complete and partial dentures.
Following are suggested initial GUIDELINES for MINI IMPLANT USE:
Type I and II (Misch) bone sites are most appropriate for mini implants
Minimum of 1-mm thickness of facial and lingual cortical bone
Approximately 100 mm occlusal relief for fixed prosthetics A rounded minimal occlusal table
Minimum space of 0.5 mm between tooth and mini implant
Minimum of 6 mini implants for removable complete dentures in the maxilla
Minimum of 4 mini implants for removable complete dentures in the mandible
Minimum of 10 mini implants for SPLINTED FIXED complete prosthetics in the MAXILLA
Minimum of 8 mini implants for SPLINTED FIXED complete prosthetics in the MANDIBLE.
Implant protective type of occlusal scheme for fixed Prosthetics.
Esthetic requirements are addressed preoperatively
Polyurethane working die material or material of similar durability
EXTRA DYE SEPARATOR may be indicated
Most of the mini-implant evidence is based on retrospective data, case series, or uncontrolled studies. Randomized, controlled, prospective, longitudinal human trials are needed to further validate this treatment.
5: MDI ClinicalStudies from AroundTheUSA Willimantic,Connecticut 2006
IMPLANT-SUPPORTED FIXED PROSTHETIC TREATMENT USING VERY SMALL-DIAMETER IMPLANTS: A CASE REPORT 2006
Dennis Flanagan, DDS, is in private practice in general dentistry. Address correspondence to Dr Flanagan at 1671 West Main Street, Willimantic, CT 06226 (e-mail: firstname.lastname@example.org).
Journal of Oral Implantology 34 Vol. XXXII/No. One/2006
Patients present for implant treatment with variable amounts of bone volume, ridge length, and interocclusal space. Some sites are NOT amenable to the standard sizes of many available implants.
Most dental-implant companies offer standard-diameter implants in the range of 3.75 to 4.2 mm, but smaller diameters are available from 2.0 to 3.3mm
Patients present for implant treatment with VARIABLE amounts of bone volume, ridge length, and interocclusal space. Some sites are NOT amenable to the standard sizes of many available implants.
Small-diameter implants have been used for retention of complete maxillary and mandibular overdentures, but there is a dearth of reports for their use in FIXED prosthetics.5 (Mazor Z, Steigmann M, Leshem R, Peleg M. Mini-implants to reconstruct missing teeth in severe ridge deficiency and small interdental space: a 5 year case series. Implant Dent. 2004;13:336–341.)
STANDARD available implants may NOT be appropriate for patients' compromised sites when the patients present for treatment.
An up-to-date and pervasive knowledge of the ARRAY of implant SIZES and SHAPES is an ASSET for treatment.
Implant diameters are available from 1.8 to 8 mm.
Many implantologists believe that a smaller-diameter implant is MORE DESIRABLE than a LARGER larger one for REASONS of BLOOD SUPPLY ,that is, LARGER -diameter implants may IMPEDE the blood supply to bone surrounding the implant.
Additionally, if an unforeseen bone density or site inadequacy is encountered during the osteotomy of a small-diameter implant, the use of a slightly larger-diameter implant that is able to attain better initial stability remains an option, if there is adequate space.
Consequently, it may be BETTER to have a BIAS TOWARD a smaller-diameter implant rather than one with a larger diameter.
At times, larger- diameter implants may be better suited in the esthetic zone for emergence profile of the crown.
STANDARD available implants may NOT be appropriate for patients' compromised sites when the patients present for treatment.
An up-to-date and pervasive knowledge of the ARRAY of implant SIZES and SHAPES is an ASSET for treatment and the implantologist.
Implant diameters are available from 1.8 to 8 mm
The use of very small- or mini-diameter implants may be advantageous.
Sites with inadequate length may be suited for these implants to provide adequate support for the prosthesis.
The AVAILABLE BLOOD SUPPLY around and about a SMALL diameter implant may be BETTER than that of a LARGER -diameter implant.
Sites accepting these small-diameter implants should be of denser bone types I and II.
FIGURE 1. Preoperative radiograph. FIGURE 2. Postoperative radiograph of 1.8-mm diameter implants. ,
FIGURE 3. Slightly prepared coronals. FIGURE 4. Cemented prosthesis in place.
6: MDI ClinicalStudies from AroundTheUSA Willimantic,Connecticut 2008
Fixed Partial Dentures and Crowns Supported by Very Small Diameter Dental Implants in Compromised Sites
Dennis Flanagan, DDS 2008
IMPLANT DENTISTRY / VOLUME 17, NUMBER 2 2008 183
Very small diameter (1.8 –3.3 mm) dental implants may be successfully used to support FIXED partial dentures in edentulous sites of COMPROMIZED bone width or length.
Very small implants can be successfully used in highly selected sites where there is ADEQUATE bone density and bone volume for immediate implant stability.
Adequate or augmentable attached gingiva may be a requirement. A small diameter implant presents less of an obstacle for angiogenesis and there is less percutaneous exposure and bone displacement as compared with standard sized implants. In posterior sites, rounded and narrow prosthetic teeth present small occlusal tables to minimize ax- ial and off-axial directed forces.
MULTIPLE SPLINTED IMPLANTS may be necessary to minimize metal FATIGUE from cyclic loading.
Anterior restorations supported by mini implants may need occlusal relief to minimize the effects of cyclic loading. (Implant Dent 2008;17:182–191)
Key Words: mini implant, occlusal scheme, bone density, bone ridge
There are case reports that demonstrate where compromised sites are re stored with 1.8 to 3.3 mm diameter implants that support FIXED partial denture prostheses.5–7
However, these very SMALL diameter implants, when used individually or in MULTIPLES or in COMBINATION with LARGER sized implants, may offer ADEQUATE support as compared with STANDARD sized implants.
In posterior sites, rounded and narrow prosthetic teeth present SMALL OCCLUSAL TABLES to minimize axial and off-axial directed forces.
Multiple splinted implants may be necessary to minimize metal fatigue from cyclic loading. After trauma or years of bone resorption patients can present for implant treatment with variable amounts of bone volume, length and height of ridge, and interocclusal space. Some sites CANNOT accept the standard sizes of many available implants without site development.
There is some debate as to the true supportive quality of GRAFTED BONE .
Major bone grafting procedures of extremely resorbed mandibles may NOT be justified.
(Int J Oral Maxillofac Implants. 2006 Sep-Oct;21(5):696-710.
The efficacy of various bone augmentation procedures for dental implants: a Cochrane systematic review of randomized controlled clinical trials.
Esposito M1, Grusovin MG, Coulthard P, Worthington HV.)
A 61-year-old women had a cari- ous tooth #30 extracted (Figs. 4–6) (Table 1). After 4 months of healing, two 2 1.5 mm implants (Intra Lock, Ultimatics, Ardmore, OK) were placed and restored with a 2 unit por- celain fused to metal crown splint.
A 42-year-old women lost #30 due to failed endodontic therapy (Figs. 7–10) (Table 1). The tooth was sec- tioned and atraumatically extracted and the site allowed to heal for 4 months. Two one-piece 3 mm 12 mm (BioHorizons) were placed flap- lessly by infiltration local anesthesia (articaine). After 4 months waiting for osseointegration, the coronal ends were prepared for splinted crowns. The crowns were cemented with zinc phos- phate cement. The patient has been functioning successfully for 2 years.
A 40-year-old man had lost his mandibular right posterior teeth (Figs. 11–13) (Table 1). The site at #28 was adequate but the edentulous site at #29 –32 was very narrow, precluding implant placement without extra- cortical bone grafting. Four 2 1.5 mm (IntraLock) and a 4 0 mm (3-I) implants were placed and restored with a splinted fixed partial dent
These cases demonstrate that single and multiple very small implants may successfully support crowns or FIXED partial dentures where there is appropriate bone and occlusal considerations.
These sites are usually found in the POSTERIOR mandible and anterior maxilla and mandible.
Because bone volume and quality and ridge length can present the implantologist with a challenge for restorative treatment, creative but effective solutions may need to be considered.
An up-to-date knowledge of the ARRAY of implant sizes and shapes is an asset for treatment.
Bone density of type I, II or III, bone site length of at least 4 mm, bone available height of at least 10 mm and at least 1 mm of attached or augment- able gingiva are desirable. Any in- traoral locat However, LESS dense bone may require the use of LONGER small diameter implants to resist occlusal forces and present less per square millimeter of bone compression during service.
Conversely, there may be PHYSIOLOGIC ADVANTAGE to very small diame- ter implants. An ADVANTAGE that very small diameter implants have over standard diameter implants is the LESSER amount of linear or CIRCUMFERENTIAL PERCUTANEOUS EXPOSURE and BONE DISPLACEMENT.
The circumference of a 2 mm implant is ( diameter) 6.28 mm whereas the circumference of a standard 4.0 mm diameter implant is 12.56 mm.
The very small implant has HALF of the linear percutaneous exposure thus exposing LESS of the implant- gingival attachment to BACTERIAL ATTACK.
There is also a smaller silhouette of the very small diameter implant that may present a BARRIER to ANGIOGENESIS and OSTEOGENESIS .
Because dental implants are cylinders or near-cylinders, a mathematic calculation of the outline form or the silhouette area, of a 2 x 10 mm implant may be compared with a 4 x 10 mm implant. Where the area is diameter (width) height. So, 2 x 10 mm 20mm2 and4 x 10mm 40 .
The 2 mm diameter implant presents a barrier to the osseous physiology that is half that of the 4 mm diameter implant. With respect to volume of the cylinder, where volume ( 3.14) (radius squared) (cylinder height), then3.14 square mm 10mm 31.4 mm3 and, 3.14 square mm 10 mm 125.6 cm3.
So to compare these volumes: 125.6/31.4 4.
The 4 mm diameter implant has 4 times the osseous displacement as compared with the 2 mm diameter implant. This difference may be im- portant. Intuitively, this may be a physiologic advantage for the very small diameter implant in that there may be more of an available osseous blood supply for the implant support- ing bone or less of a barrier. In larger diameter implants this larger barrier to blood supply or angiogenesis may contribute to the classic "resorption to the first thread" in the larger implant. The larger barrier may hinder angio- genesis and subsequent osteogenesis around a newly placed implant. Blood supply at the osseous crest may be hindered
With respect to VOLUME of the CYLINDER , where volume = 3.14 x radius squared x cylinder height then3.14 squaremm 10mm 31.4 mm3 and, 3.14 square mm 10 mm 125.6 cm3.
So to compare these volumes: 125.6/31.4 =4
The 4 mm diameter implant has 4 times the OSSEOUS DISPLACEMENT as compared with the 2 mm diameter implant.
This difference may be important.
Intuitively, this may be a PHYSIOLOGIC ADVANTAGE for the very small diameter implant in that there may be MORE of an available OSSEOUS BLOOD SUPPLY for the implant supporting bone or less of a barrier. In larger diameter implants this larger barrier to blood supply or angiogenesis may contribute to the classic "resorption to the first thread" in the larger implant. The larger barrier may hinder ANGIOGENESIS and subsequent OSTEOGENESIS around a newly placed implant. BLOOD SUPPLY at the osseous crest may be HINDERED by the larger implant and produce the characteristic resorption to the first thread. This phenomenon does not seem to be prevalent with the 2 mm diameter implants. Figure 15 shows 3 implants
This CREST BONE RESORPTION phenomenon does not occur in submerged implants but only after second stage uncovery and placement of an abutment. With the very small 2 mm diameter implants this does NOT seem to be prevalent. This may be the result of the smaller diameter and/or the lack of an abutment with a MICROGAP.
The available bone for an implant site in many cases can leave much to be desired. In these cases, the occlusion, a REDUCED VERTICAL DIMENSION and ridge length can present a dimensional problem for space. Very small diameter implants can fit into many of these atrophic sites with adequate interimplant and interocclusal spacing. Esthetics may be a problem in certain sites and caution is advised here.
These very small diameter implants CAN FIT into sites that CANNOT accept standard diameter implants without augmentation. The implants in these case series were generally placed flaplessly or with a split thickness apically positioned flaps thus retaining the periosteum and its blood supply and retaining or increasing the attached gingiva. The bone in these atrophic sites is typically type I or II and well suited for initial implant stability.
Very small diameter implants have been used for many years in completely edentulous cases to retain overdentures without bone grafting. Extracortical bone augmentation grafting may delay implant placement and the resulting grafted bone may not be truly supportive for the implant for many months or years or possibly never.
The BONE at the CREST of the THIN ATROPHIC RIDGE may be DENSE CORTICAL BONE ,which can be VERY SUPPORTIVE for Implants. Posterior sites in the mandible, not in the esthetic zone, may be appropriate for very small diameter implants that support a fixed partial denture.
The FORCES in the POSTERIOR JAWS can be greater than 1000 N of force but this magnitude is in the axial direction of the implant.8 The off-axial vector directive of these forces is much less. The cyclic loading that characterizes human occlusion may induce metal fatigue in very small diameter implants.
Very small diameter implants may need to be used in MULTIPLES to preclude cyclic loading metal fatigue and implant fracture in the posterior mandible9 (Figs. 7, 11).
Unpublished proprietary company (Intralock) data and unpublished data from the author suggests that single 2 mm diameter implants can withstand cyclic direct horizontal coronal loads of 200 N of more than a million cycles. This force represents the maximum force in the anterior jaws that may be humanly generated in the vertical or occluso-apical direction but this force was applied directly horizontally or facio-lingually for the test.
In anterior sites that have adequate width but inadequate length, a very small implant may be appropriate for a single Implant.
In anterior sites that have adequate width but inadequate length, a very small implant may be appropriate for a single implant.5,10 The forces in the anterior jaws can be about a third of the posterior forces, 50 to 200 N. These forces in occlusion, however, are delivered not axially but off axi- ally, a vulnerable direction for the im- plant. This may require more dense bone to resist the higher per square millimeter force placed on the bone by the smaller diameter implant body. Denser bone may preclude micro- movement of the implant and failure of the implant by fibrous replacement. The crowns in these cases may be best left slightly or somewhat out of occlusal contact in centric position and all excursions.
Very small implants may be used in conjunction with standard diameter (3.75– 4.1 mm) implants to support a FIXED prosthesis where there is an area of thin bone next to or near an area that will accept a standard diameter implant.
The cost of very small diameter implants can about 20% to 50% less than standard diameter implants mak- ing treatment less expensive.
If during the osteotomy of a small diameter implant there is an unfore- seen bone density or site inadequacy, the use of a slightly larger diameter implant that is able to attain better initial stability remains an option, given adequate space and density or bone manipulation techniques such as ridge expansion or splitting. Consequently, it may be better to have a bias to placement of smaller diameter than larger diameter implants.
Larger diameter implants may be better suited in the esthetic zone to provide for the emergence profile of the crown. However, in anterior compromised sites, especially where there has been site length attenuation, smaller diameter implants may be appropriate when the occlusal forces can be minimized or eliminated.
When placing very small implants, it is the experience of this author that placement torque should not exceed 50 Ncm. Over compression of the bone may lead to osseous compression necrosis and the implant may fail to integrate. Additionally, higher torque forces may cause fracture of the implant shaft.
Tarnow et al13 determined that there is a 1.4 mm CIRCUMFERENTIAL BONE CREST RESORPTION about implants. This may mean that the appropriate implant site width is the diameter of the proposed implant plus the 1.4 mm cir- cumferential bone resorption at each perspective. Thus, a 4.0 mm diameter implant would require: 4.0 mm 1.4 mm (facially) on 1.4 mm (lingually) 6.8 mm bone width. Very small 2 mm diameter implants do NOT seem to demonstrate this phenomenon. Because of this information smaller diameter implants may be MORE APPROPRIATE for many COMPROMISED SITES.
Knowledge of the available ARRAY of IMPLANT SIZES is an asset for the implantologist. Sites accepting these small diameter implants in this case series were perceived to be of denser bone types I, II and III.
There will be an increased per square millimeter force exerted on the supporting bone by the implants during function. So, MULTIPLE implants may be necessary to dissipate forces among the implants to minimize osseous stress.
POSTERIOR PROSTHETIC TEETH were made in these cases with rounded cusps and NARROW OCCLUSAL TABLES that present a small area for functional occlusal impact and to minimize off- axial forces.
Zinc phosphate cement (Flecks) was used to lute all cases listed but resin modified glass ionomer or resin cement can also be used. Because these implants are not used with conventional osteotomy
Patients who present with a complete maxillary denture with remaining only mandibular anterior teeth may benefit from this modality.
These patients usually have thin atrophic posterior residual ridges that will not accept a standard diameter implant WITHOUT OSSEOUS GRAFTING.
Because the forces generated by these complete denture patients is generally less than with natural dentition, very small diameter implants may very successfully support FIXED posterior splinted partial dentures.
This treatment may prevent these patients from developing combination syndrome, where there is supereruption of the remaining anterior teeth, fibrous replacement of the ante- rior maxilla and continued atrophy of the posterior edentulous ridges.
Because these implants are NOT used with conventional osteotomy drills but with very thin drills. If the thin ridge is split and expanded with a #15 scalpel the appropriate bone width for a proposed site may be the sum of postoperative peri-implant bone crest resorption of 1.4 mm at facial and lingual, or 2.8 mm. However, there may not be as much resorption as a standard sized implant and the osseous resorption of 1.4 mm seems to not apply to mini implants. This type of osseous crest resorption may not be prevalent with these implants possibly because of less impedance of the blood supply.
So a very narrower ridge may successfully accommodate the mini implant.
7: MDI ClinicalStudies from AroundTheUSA Willimantic,Connecticut 2016
Case for Smaller Diameter Implants 2016
Dr. Dennis Flannigan
Journal of Oral Implantology : 10.1563/aaid-joi-D-16-00106
Previous work in the dental literature has discussed occlusal over load of dental implants in function.1 Thus larger diameter implants have been advocated.1
However, there are other considerations that may come into play that effect the longevity of an implant. The major parameters are DISPLACEMENT of the IMPLANT, OCCLUSAL OVERLOAD, and PERCUTANEOUS CIRCUMFERENCE.
It may be that the actual larger displacement of LARGE diameter implants IMPEDES BONE REMODELING , especially at the crest where the bone may be thinner at the facial and lingual as compared with the deep medullary bone.2,4
Even if the crestal bone is greater than 1.8 mm the larger implant may prevent adequate angiogenesis for bone remodeling.3,5 Blood supply is important for remodeling. Large diameter implants generally have higher removal torque at initial placement and better stability than smaller diameter implants.1
However, the large physical displacement of wide diameter implants may impede bone remodeling. There may be resorption but not apposition.2 There may be a physical barrier for the blood supply that would inhibit apposition but allow resorption to occur.2,6–8
Assuming, for the sake of simplicity, a length of 10 mm and the implant is a cylinder, the volume of a 5.7 mm implant is 255.047 cubic mm. The volume of a 2.5 mm 3 10 mm implant, again assuming a cylinder, is 49.06 cubic mm. This larger volume may physically impede blood supply and thus impede activity of osteoclasts and osteoblasts thereby impeding remodeling, which in turn may make the cervical supporting bone and epithelial attachment susceptible to peri-implantitis.
Occlusal overload is not generally an issue with large diameter implants due to the large surface area. Dental implants are capable of resisting an axial load beyond human capability. Off-axial loads, however, may not be adequately resisted by the facial or lingual cortices depending on bone quality and volume. A large diameter implant spreads any off axial loads over a larger area than small diameter thus lowering the per square millimeter load on the supporting bone.3
Mini implants, ,3.0 mm in diameter, may demonstrate little or no bone loss over many years of service.9
Nonetheless there is a larger per-square-millimeter load on the supporting bone.
Thus control of the off-axial occlusal load is KEY..
Nonetheless, the small surface area puts a larger per-square-millimeter load on the bone.
This necessitates more dense bone or MULTIPLE SPLINTED IMPLANTS to LESSEN the risk for overload on the supporting bone.6–8
Percutaneous circumference may put LARGER diameter implants at risk for PERI-IMPLANTITIS .2,4
Large diameter implants have a much larger percutaneous circumference as compared with small diameter implants. The small diameter/circumfer- ence may lessen the risk for late peri-implantitis. At least 1 study suggested that larger diameter implants may be more prone to peri-implantitis.5 The percutaneous circumference of a 5.7 mm implant is 15.7 mm whereas that of a 2.5 mm diameter implant is 7.85 mm, which is a dramatic difference. The smaller circumference presents less of an opportunity for invasive bacteria and less risk for any epithelial detachment and infection. 6–8
Impeded remodeling and increased percutaneous exposure may increase the risk for peri-implantitis in large diameter implants. There may be less risk for peri-implantitis with small diameter implants. Large diameter implant fixtures could be more prone to late peri-implantitis. Long-term randomized controlled studies are needed to elucidate this issue. It may be appropriate to only place implants of a diameter to a maximum of 4.7 mm because larger diameters may impede bone remodeling and present a longer percutaneous exposure.
It is NOT known what thickness, volume, or quality of bone is needed to adequately resist a given occlusal load. It may be that small diameter implants may be surprisingly able to survive long-term occlusal loads. Thus, when selecting an implant for a site, it may be better to err on the side of THIN.
Dennis Flanagan, DDS, MSc Willimantic, Conn
8: MDI ClinicalStudies from AroundTheWorld Padova,Italy Beirut ,Lebanon 2004
Clinical evaluation of small-diameter implants in single-tooth and multiple-implant restorations: a 7-year retrospective study. 2004
Vigolo P1, Givani A, Majzoub Z, Cordioli G.
Int J Oral Maxillofac Implants. 2004 Sep-Oct;19(5):703-9.
Placement of small-diameter implants often provides a solution to space-related problems in implant restoration. This 7-year retrospective study presents results from 192 small-diameter implants placed in 165 patients from 1992 to 1996.
MATERIALS AND METHODS:
The dental records of each patient were reviewed. The implants, which were either 2.9 mm or 3.25 mm in diameter, were placed by 2 different surgeons. All prosthetic appliances were fabricated by the same prosthodontist. Ninety-four implants supported single-tooth cemented restorations; the remaining 98 implants supported cemented or screw-retained partial prostheses.
The total implant survival rate was 95.3%. Four implants were lost at second-stage surgery, and 5 more were lost after loading.
SMALL-diameter implants demonstrated a SURVIVAL RATE SIMILAR to those reported in previous studies of STANDARD-size implants.
The results suggest that small-diameter implants can be SUCCESSFULLY INCLUDED in implant treatment. They may be PREFERABLE in cases where space is limited.
9: MDI ClinicalStudies from AroundTheUSA Buffalo,New York 2003
Mini Dental Implants for the General Dentist
A Novel Technical Approach for Small Diameter Implant Placement
Todd Shatkin,DDS ,Samuel Shatkin,DDS,MD,
JADA 2003 Vol. 24,No. 11
Compendium / November 2003
10: MDI ClinicalStudies from AroundTheUSA Buffalo,New York 2007
Mini Dental Implants for Long-Term Fixed and Removable Prosthetics: A Retrospective Analysis of 2514 Implants Placed Over a Five-Year Period
Todd E Shatkin, DDS; Samuel Shatkin, DDS, MD; Benjamin D. Oppenheimer, DDS; Adam J. Oppenheimer, MD 2007 February 2007 Issue - Expires February 28th, 2009
Compendium of Continuing Education in Dentistry
Over the past decade, endosseous implants of increasingly smaller diameters have been introduced into the field of dentistry. Small diameter implants (SDIs) are generally 2.75 mm to 3.3 mm in diameter. They are frequently used in cases of limited alveolar anatomy. Mini dental implants (MDIs) are smaller than their SDI counterparts, with diameters ranging from 1.8 mm to 2.4 mm.
They are suitable for long-term use—a task for which the device was approved by the Food and Drug Administration.
The following study describes the authors' experience with MDIs under this indication. Over a 5-year period, 2514 MDIs were placed in 531 patients. The mean duration of follow-up was 2.9 years.
The implants supported FIXED (1278) and removable prostheses (1236), with nearly equal placement in the mandible and maxilla (1256 and 1258, respectively).
The overall implant survival was 94.2%. Based on a Cox proportional hazards model, statistically significant predictors of failure include use in removable prostheses (hazard ratio = 4.28), the posterior maxilla (3.37), atrophic bone (3.32), and cigarette smokers (2.28). Implant failures (145) were attributed to mobility with or without suppuration (19% vs 81%, respectively). The mean failure time for these implants was approximately 6.4 months (193 ± 42 days). This temporally correlates with the osseointegration period. A learning curve was established for this procedure, and implant survival improved with placement experience.
Based on these results, the authors have devised treatment guidelines for the use of MDIs in long-term FIXED and removable prostheses.
MDIs are not a panacea; however, proper training enables the general dentist to successfully implement MDIs into clinical practice.
- See more at:
11: MDI ClinicalStudies from AroundTheUSA Buffalo,New York 2012
Mini Dental Implants: A Retrospective Analysis of 5640 Implants Placed Over a 12-Year Period 2012
Todd Ellis Shatkin, DDS; and Christopher Anthony Petrotto
Compendium , Volume 33,Special Issue 3. September 2012
Mini dental implants are becoming increasingly popular in dental care today. Because of their smaller size they are often used in cases of limited bone anatomy. Mini dental implants have diameters ranging from 1.8 mm to 3 mm and are suitable for long-term use.
This article describes a retrospective analysis of 5640 mini dental implants placed into 1260 patients over a 12-year period. The mean length of follow-up was 3.5 years. The implants placed supported removable (2319) and FIXED prostheses (3321), with placement in the maxilla (3134) and mandible (2506).
The overall implant survival was 92.1%. Failures of implants (445) were attributed to mobility of the implant; the mean time to failure for these implants was 14.4 months. The small size of these implants has led to the development of techniques that enable placement and use in a short amount of time for both the doctor and patient.
The high rates of success show that mini dental implants are suitable for use in supporting FIXED and removable prosthetics.
Using mini dental implants that enable immediate denture stabilization, or single and multiple-tooth replacement in as little as one visit,3 is clearly desirable to patients.
The relatively lower cost of mini dental implants allows for a larger patient-selection base.
Christensen described these implants as simple, predictable, minimally invasive, and relatively inexpensive.4
Additionally, the osseointegration period required for mini dental implants can be significantly shorter than that for conventional implants because of a less aggressive insertion procedure (ie, minimized disruption of the periosteum).
- Because mini implant insertion requires minimal disruption of the periosteum, there is reduced damage to the insertion area.2
Mini dental implants and their function in immediate loading for denture stabilization and FIXED fixed restorations have become increasingly prevalent in the literature.
Implants supporting fixed prostheses were considerably more successful than those supporting removable prostheses, having success rates of 94.7% and 88.4%, respectively.
Further analysis of location of placement revealed a lower mini implant success rate in the maxilla (90.3% anterior; 92.5% posterior) relative to the mandible (92.3% anterior; 94.1% posterior). The reduced implant success rate in the maxilla was likely due to its poorer bone quality relative to the mandible.
Though there exists greater OCCLUSION in the posterior regions of the mouth, higher implant success rates in those areas may be attributed to the use of MULTIPLE implants to support a prosthesis, mimicking the natural root anatomy. Often, TWO(2) implants were used to replace single molars and MULTIPLE implants were used for posterior restorations involving more than one tooth.
Gender also played a role in the survival of implants. Of the 3378 implants placed in females, the overall success was 93.0%, while the success rate of the 2262 implants placed in males was only 90.8%.
Implants were placed in patients aged 13 years old to 95 years old. The distribution of implants by patient's age is shown in Figure 17. Patients 21 to 30 years of age had the highest rate of success at 95.8%.
There were 445 implant failures observed.
Implants considered as failed presented as being mobile or fractured.
Of those implants that failed, the majority did so in the first 6 months following implantation. Implants not failing in this time following insertion likely attained osseointegration. This correlates with Brånemark's classical definition of osseointegration of 3 to 6 months in the mandible and 6 to 9 months in the maxilla.21
With the growing demand from patients for fewer office visits, lower cost procedures with immediate results, and shorter recovery time, dental rehabilitation techniques have been developed for minimally invasive, single-stage implant placement. The mini dental implants used in these procedures have been demonstrated to have high success rates. Over a 12-year period, 5640 mini dental implants were placed with an overall survival of 92.1%.
With the proper training,22 consideration for prosthetic subtype, implant location, size, and patient variables, mini dental implants can provide exceptional outcomes. These results are rewarding for the dentist, minimally invasive and affordable to the patient, and have long-term success for both FIXED and removable prosthetics.
12: MDI ClinicalStudies from AroundTheUSA Buffalo,New York 2017
A Mini Dental Implant Alternative to All-on-Four 2017
Dr Todd Shatkin Brooke Sadkin, and Jared Shatkin
Aesthetic dentistry has evolved throughout the past few decades, specifically in the field of implantology. Patients are preferring endosseous procedures to traditional dentures and other removable prostheses to increase stability and comfort, and to decrease pain.1 Conventional implants require several procedures involving multiple appointments and upwards of a year until completion; although some newer techniques promote a faster completion time. The "All-on-4" technique is an immediate conventional implant procedure in which 4 large-diameter implants (2 in the anterior and 2 in the posterior) are inserted at a 45° angle to take advantage of the available bone and to reduce the need for bone augmentation and/or sinus lift.2 According to Nobel Biocare's All-on-4 treatment concept manual, a minimum of 5.0 mm in bone width and 8.0 mm in bone height is necessary to begin the procedure.3 (All-On-4 is a registered patent owned by Nobel Biocare developed together with Paulo Malo, DDS, PhD, at the MALO CLINIC.) Though the All-on-4 technique claims to eliminate the need for bone augmentations and sinus lifts, these procedures cannot always be eliminated if the bone quantity does not meet the requirements due to the large diameter of a conventional implant.1-2,4 While the All-on-4 technique offers acceptable support with 4 implants, the endosseous procedure is still invasive and time consuming compared to the immediate and early loading procedures used with mini dental implants. The All-on-4 often requires a minimum of 4 to 6 months before the final restoration is fully completed.4 In addition, if one of the 4 implants fails to integrate or fails following placement of the restoration, the entire restorative procedure must be restarted, additional surgery performed, and the restoration remade. Considering the average fee for All-on-4 is in the range of $30,000 to $40,000 per dental arch, this technique is not affordable for most dental patients.
Technique Using Mini Dental Implants Recently Introduced
Immediate and early loading endosseous procedures with mini dental implants are more desirable to patients in many instances because of the speed of completion, an affordable fee, and it is a less invasive procedure with reduced postoperative discomfort.4 The small size of the mini dental implants (available in several lengths and diameters) eliminates the need for bone augmentation and/or sinus lifts. This is because the mini dental implant can be angled into available bone rather than augmenting the bone.4 The Shatkin Fabricated Implant Restoration and Surgical Technique (F.I.R.S.T.) (patent USPTO No. 7,108,511 B, September 2006; developed by Todd E. Shatkin, DDS) provides for mini dental implant(s) to be placed and restoration(s) cemented in one patient visit.5 The most recent innovation, FIX on SIX (FIX on SIX is a registered trademark owned by Shatkin F.I.R.S.T., developed by Todd E. Shatkin, DDS) offers a combination of the Shatkin F.I.R.S.T. technique using 6 to 8 (or 10) mini dental implants with a 12-unit fixed detachable zirconia full-arch restoration with o-ring implant housings. The restoration is only removed at recall cleanings as the dentist is able to snap off the FIX on SIX restoration. The hygienist will then completely clean the implants, the restoration, and the surrounding tissue and easily reinsert the restoration without patient discomfort. This FIX on SIX procedure is completed in a fraction of the patient's and the dentist's time as required by the All-on-4 technique. The success rates of the immediate loading mini dental implant endosseous procedures are competitive with the All-on-4 technique. If one of the mini dental implants were to fail with a FIX on SIX restoration, the failed mini implant can be easily replaced with a new mini implant and o-ring housing placed in the same or different location. In addition, the FIX on SIX restorations are considerably more affordable than the All-on-4 with approximately a 50% to 66% savings. Consequently, the FIX on SIX restorations are more desirable to the patient due to their affordability, greater comfort, reduced treatment time, and the less invasive nature of the procedure.
Fixed partial dentures are commonly supported by mini dental implants to provide a natural, aesthetic appearance for the patient. In recent years, zirconium dioxide (zirconia) frameworks have been used in dentistry for fixed restorations.6 The introduction of zirconia has allowed the fabrication of metal-free prostheses via CAD/CAM technology. The result is improved aesthetics with increased success and reliability.7 There is also evidence that there is less plaque accumulation on zirconia, helping to prevent postoperative gingival problems.8 The architecture of these zirconia-based prosthetics enables superior strength and chewing resistance on the posterior teeth relative to other ceramics.5,9 Due to its favorable chemical composition and mechanical properties, clinicians have been eager to use zirconia in implant-supported restorations after its continued success in tooth-supported restorations.10 The following case study (Figures 1 to 15) presents a clinical report of mini dental implants with the FIX on SIX technique. The use of 6 to 8 (or 10) mini dental implants allows for the functional and aesthetically pleasing zirconia fixed prosthesis to be supported. Using CBCT technology, a zirconia prosthetic restoration was created and fixed over Shatkin F.I.R.S.T. mini dental implants (by Intra-Lock) using o-ring housings processed into the zirconia framework.
A 56-year-old male patient with an upper denture presented for a consult on May 13, 2016. He had come in after seeing the Shatkin F.I.R.S.T. television marketing campaign. At the consult, our new patient had a CT scan (using our Shatkin F.I.R.S.T. CBCT machine for pre-op and post-op scans) (Figure 1), treatment plan, and impressions taken for a FIX on SIX detachable-removable bridge (Figure 2). To minimize the discomfort and to eliminate the existing issues with his old denture, a zirconia bridge was prescribed and designed to fit on the mini dental implants that would be placed. Zirconia was chosen as the fabrication material due to its strength and durability and resistance to plaque. A treatment plan for placing 10 Mini Drive-Locks (MDL [Intra-Lock]) in the maxillary arch using the Shatkin F.I.R.S.T. technique for mini dental implant placement was chosen. He was asked to return in 2 weeks for his procedure and placement of a temporary bridge.
About one month later, the patient returned, signed the consent form, and treatment was begun. A local anesthetic (2 carpules of Septocaine with epinephrine [Septodont]) was administered. A CT guided stent from Shatkin F.I.R.S.T. Lab was used in this case. The position of the 10 implants was marked using a Thompson marking pen and the CT guided stent (Figure 3). Nine Intra-Lock mini dental implants were used on the upper maxillary arch, size 25 mm/15 mm at Nos. 3 to 6 and 9 to 13; and one 25 mm/11 mm for No. 8. The CT-guided stent was used throughout the procedure (Figure 4), removing it between final placement of each implant, using the patented F.I.R.S.T. technique. When finished placing all 10 implants using the Shatkin F.I.R.S.T. procedure, the housings were placed, and A1 Luxatemp (DMG America) was used to create the temporary bridge. The patient liked the temporary. Impressions were taken and sent to the Shatkin F.I.R.S.T. Lab (Figures 5 to 8). Two prescriptions (penicillin 500 mg, Norco 5/325) were sent to the patient's pharmacy, and an appointment for 2 weeks was made for the delivery of the permanent FIX on SIX detachable-removable bridge. Two weeks later, the patient returned, and the temporary was removed. The FIX on SIX detachable-removable roundhouse restoration was then placed (Figures 9 to 12). The FIX on SIX restoration had good aesthetics, and the patient was happy (Figure 13 to 15). The patient was given a Shatkin Water Flosser and a Sonicare (Philips Oral Healthcare) toothbrush. These are provided as a part of the treatment to our mini implant patients for optimal home care. These have been very successful hygiene tools to keep the soft tissues healthy and clean between checkups, when the FIX on SIX is removed.
This article presents an alternative to All-on-4 that is less expensive, less invasive and painful, and demonstrates faster results while utilizing zirconia, a strong and biocompatible dental material. FIX on SIX is a beautiful zirconia restoration that can be removed by the clinician while providing the patients with the feel and aesthetics of a fixed prosthesis. Creating a fixed prosthesis that is able to withstand the occlusal forces applied, while providing cosmetic appeal and patient satisfaction, is an enduring task for all dentists.11 Today in dentistry, zirconia has traditionally been used in fixed partial dentures as tooth-supported restorations.9,10 With most cases that use zirconia as a fixed restoration, high success rates have been recorded, mostly higher than 95%.9 Zirconia's ability to increase the durability of a prosthesis by up to 30% to 40% has made it a good candidate for use in fixed-hybrid cases.11 The use of CT technology increases zirconia's stability in conjunction with decreasing failure rates of these restorations, due to the industrial processing. In this case study, the patient was dissatisfied with his upper denture because of cracks in the acrylic along the palate, and the dentures were not comfortable to wear, and food would trap under them. By designing a fixed zirconia bridge (FIX on SIX) instead of acrylic dentures or a hybrid acrylic fixed bridge, the patient will no longer have these negative experiences. The use of zirconia instead of acrylic increases durability of the prosthesis while also offering the comfort of fixed restoration and healthier surrounding gingival tissues.
13: MDI ClinicalStudies from AroundTheUSA Provo,Utah 2010
The Truth About SMALL Diameter Implants
Implants Dent Today. 2010 May;29(5):116, 118, 120.
Christensen GJ1, Child PL.
SDIs that are treatment planned correctly, placed and loaded properly, and are within a well-adjusted occlusion, are working in an EXCELLENT manner for the patients described in this article.
It is time for those practitioners unfamiliar with SDIs and their uses to discontinue their discouragement of this technique.
SDIs are easily placed, minimally invasive, and a true service to those patients described. They do not replace conventional diameter implants; however, they are a significant and important augmentation to the original root-form implant concept. There is obvious evidence of the growing acceptance of small-diameter implants by both general practitioners and specialists.
If we listened to and believed some of the comments about small-diameter implants (SDIs) (or "mini" implants) that we hear coming from some areas of surgical dentistry, we would be led to think that these devices simply do not work. However,the TRUTH is DIAMETRICALLY opposed to what some are saying, and it has been our observation that some of the most severely negative comments come from dentists who have NEVER PLACED SDIs.
This article includes: the definition of "mini" or SDIs; a discussion of the evolution of SDIs, including their clearance by the US Food and Drug Administration (FDA) and research support; reasons for SDI use instead of conventional diameter implants; the indications for SDI use; and suggestions on how to use them successfully.
The FDA cleared these conventional-diameter root-form implants for clinical use in 1976. Millions of conventional-diameter implants have been placed for more than 4 decades, and their cumulative success rate of around 95% is impressive.
Table. Use of SDIs in Approximate Order of Decreasing Frequency of Use
Removable partial denture
Edentulous maxilla (this use has higher failure rate than edentulous mandibles)
Augmentation of fixed prosthesis
Sole support of FIXED PROSTHESIS
Salvage of previously made prosthesis
SUMMARY AND CONCLUSION
SDIs that are treatment planned correctly, placed and loaded properly, and are within a well-adjusted occlusion, are working in an EXCELLENT manner for the patients described in this article.
It is TIME for those practitioners unfamiliar with SDIs and their uses to DISCONTINUE their DISCOURAGEMENT of this technique.
SDIs are easily placed, MINIMALLY INVASIVE , and a true service to those patients described.
They do not replace conventional diameter implants; however, they are a significant and important AUGMENTATION to the original root-form Implant concept.
There is obvious evidence of the growing acceptance of small-diameter implants by both general practitioners and specialists.
14: MDI ClinicalStudies from AroundTheUSA Provo,Utah 2006
The 'mini'-implant has arrived 2006
Gordon J. Christensen, DDS, MSD, PhD
http://jada.ada.org March 2006 387 Copyright ©2006 American Dental Association.
JADA, Vol. 137
What Are Mini- Implants
When the original root-form implants were introduced, they had a diameter of about 3.75 millimeters.
Although I have heard various REASONS for selection of this diameter, the LOGIC for RESEARCH supporting these reasons has been UNCLEAR .
An implant of nearly 4 mm in diameter requires at least 6 mm of bone in a facial-lingual dimension for placement without grafting additional bone to augment the site.
After years of placing implants in all locations of the mouth, it is my observation that SELDOM do I see 6 mm of bone in a facial-lingual dimension.
Often, an osteotome must be used to widen the osteotomy and the minimal bone, thereby allowing placement of the 3.75-mm implant in the less-than-adequately sized bony site.
In the last few years, root- form implants ranging from 1.8 mm to slightly more than 2 mm in diameter have been promoted for long-term service.
IN WHAT SITUATIONS ARE MINI-IMPLANTS INDICATED?
In my opinion, I find MORE indications for narrow-diameter implants (≈ 1.8 mm) than for STANDARD- diameter implants
When inadequate bone is present for placement of standard-diameter implants, most practitioners have been taught to suggest bone grafting, either using autogenous bone (from various sites in the patient's body) or one of the many available bone substi- tutes. However, few patients desire to have, or can afford, bone grafting. The expense of dental implants already is prohibitive for most patients, without the added cost, trauma, pain and uncertainty of bone grafting. In my opinion, if dental implants are ever to achieve their optimum service potential for typical, average-income dental patients, methods need to be found to allow placement of implants in areas of remaining natural bone, using minimally invasive procedures without grafting. The mini-diameter implants have the potential to assist this challenge.
Extra support and retention under fixed partial dentures (FPDs).
Occasionally, situations arise in which an FPD is planned that has questionable potential retention from natural teeth, and the patient has refused RPD treatment or grafting and standard implants. Mini-implants can be placed in the edentulous areas and used to support the PONTIC AREAS of the FPD. When an FPD becomes loose on one end, and the prosthesis can be removed from the other abutment without destroying it, the prosthesis often can be salvaged. A small- diameter implant is placed in the pontic area, a hole is cut in the underside of the pontic, the abutment retainers of the FPD are cleaned and roughened internally, and the FPD is re- cemented using the mini- implant as additional support and retention under the pontic. Research is under way to study the long-term use of small- diameter implants as the full support and retention for fixed partial dentures.
There is no question that dental implants have been the most influential change in dentistry during the last half-century. In general, they are well-proven and highly useful. However, the diameter of standard implants (≈ 3.75 mm), along with the fre- quent need to graft bone to allow for their placement, have limited their use for those who most need implants. The introduction, approval and continuing observation of success of smaller-diameter mini-implants have stimulated use of implants in situations in which standard- sized implants could not have been used without grafting. The result has been more patients who have been served successfully at reduced cost with minimized pain and trauma patients who could not have been treated with implants otherwise. Continuing research is needed for further verification of the acceptability of mini- implants.
15: MDI ClinicalStudies from AroundTheUSA Provo,Utah 2008
Critical Appraisal MINI IMPLANTS: GOOD OR BAD FOR LONG-TERM ? 2008
Author Gordon J. Christensen, DDS, MSD, PhD* Associate Editor
© 2008, COPYRIGHT THE AUTHORS
JOURNAL COMPILATION © 2008, WILEY PERIODICALS, INC.
DOI 10.1111/j.1708-8240.2008.00204.x VOLUME 20, NUMBER 5, 2008 343
Small-diameter implants combined with natural teeth supporting a fixed prosthesis for 4 years.
In my experience, the majority of patients needing implant support for FIXED or removable prostheses do not have adequate bone present to comfortably place implants 3 mm in diameter and wider without time-consuming, painful, and expensive grafting.
NEED FOR SDIs
The following situations are the most significant clinical indications for SDIs:
1. Inadequate bone present for root-form implants 3 mm in diameter and over
Figure 1 Root-form implants 3 mm and larger in diameter need at least 6 mm of bone in a facial-lingual orientation and 10 mm of bone in a crestal-apical orientation
1. Patient lack of acceptance of grafting for reasons previously stated.
2. Health challenges precluding extensive surgical procedures.
3. Inadequate funds for compre- hensive conventional implant placement and extensive restorative restoration.
I find these indications on a daily basis, and I am thankful that alter- natives other than conventional- diameter (3 mm and over) implants are now available.
My opinion, after using SDIs for over 7 years, is that I have no question about the use of SDIs in appropriate edentulous arches or for augmentation of retention and support for removable partial dentures.
I have had success using SDIs for FIXED fixed partial dentures supported by TEETH and SDIs as well as sole support for fixed partial dentures.
In certain situa- tions, I can support the use of SDIs for sole support of single crowns. Maxillary lateral incisors and lower anterior teeth are excellent examples for single-tooth support.2 My failure rate has been far below that reported in the previous reported survey
My opinion, after using SDIs for over 7 years, is that I have no question about the use of SDIs in appropriate edentulous arches or for augmentation of retention and support for removable partial dentures.
I have had success using SDIs for fixed partial dentures supported by teeth and SDIs as well as sole support for fixed partial dentures.
In certain situa- tions, I can support the use of SDIs for sole support of single crowns. Maxillary lateral incisors and lower anterior teeth are excellent examples for single-tooth support.2 My failure rate has been far below that reported in the previous reported survey.
16: MDI ClinicalStudies from AroundTheUSA Provo,Utah 2008
CRA Foundation Newsletter
Clinician's Guide to Dental Products & Techniques
Dr. Gordon Christensen
November 2007 Issue 11.
Long term use : Because of the success of minis Minnie as transitional implants & the observed osseointegration, many clinicians began to use them as LONG TERM IMPLANTS.In 1997 Intech miniplant received FDA clearance for Intra bony and intra-radicular ...ongoing fixation",& and in 2003 the "long term intro bony applications".
Use of minis : Minis were reported most used in edentulous jaws about of both arches & for augmentation of removable partial dentures .
Augmentation of support and retention for fixed partial dentures & support for sole support of single crowns in the areas of minimal bone presence were next ,followed by transitional & orthodontic use.
Currently long-term use of small diameter implant is moving from a relatively experimental mode to MAINSTREAM PRACTICE .Small diameter implants are indicated when patients have minimal bone, denial of grafting ,poor health,minimal financial resources ,and the desire to have minimally invasive surgery accomplished .
Whether or not they will REPLACE conventional diameter implant placement in situations where EITHER COULD BE USED is yet to be determined but is LIKELY TO HAPPEN.
Mini or small diameter implants or minimally invasive, have moderate cost ,are easily accomplished and easily removed if they fail,and have excellent patient acceptance.
17: MDI ClinicalStudies from AroundTheUSA Provo,Utah 2005
The Advantages of Minimally Invasive Dentistry Observations 2005
Dr Gordon Christensen
J Am Dent Assoc,Vol 136,No. 11, 1563-1565
Miniature implants versus standard-size implants
In my opinion, during the past several years, there has been an obvious trend in dentistry toward COMPLEX techniques and accomplishing MORE treatment THAN REQUIRED .
The trend has been mentioned to me many times by colleagues as I have traveled around the world.
Recently ,I had the opportunity to speak at the annual meeting of the World Congress of Minimally Invasive Dentistry. It was refreshing to be with a group of fellow practitioners were attempting to provide OPTIMUM services for patients with the MINIMUM amount of treatment.
OFTEN ,patients do not have the minimum six millimeters of bone in a facial-lingual dimension needed for placement of conventional 4-mm–diameter implants.
The use of "mini" 1.8-mm–diameter implants allows conservative placement of implants in bone that is only 3 mm thick in a facial-lingual dimension, thus avoiding bone grafting and significant trauma and expense for patients.
Placement of these SMALL-diameter implants in MULTIPLES should be considered for optimum resistance and retention of FIXED or removable prostheses.
One widely used brand of mini-implants is IMTEC Sendax MDI (IMTEC, Ardmore, Pa.); another brand is MTI Monorail System (Dentatus, New York). Mini-implants' minimal cost and ease of placement make them desirable to patients and dentists.2
18: MDI ClinicalStudies from AroundTheUSA Provo,Utah 2008
Christensen 'embarrassed' by U.S. dentistry DrBicuspid 2008
By Laird Harrison, Senior Editor
October 28, 2008 -- The granddad of U.S. dentistry is ashamed of his family.
"What we do in America is embarrassing," Gordon Christensen, D.D.S., M.S., Ph.D., said at the ADA meeting in San Antonio this month.
With his Clinicians Report review, Scottsdale Center for Dentistry courses, frequent bylines in the Journal of the American Dental Association, and popular talks at dental meetings, Dr. Christensen may be the most influential U.S. dentist. So it means something when he deplores the state of the profession in his own country. Dr. Christensen offered several unfavorable comparisons between dentistry in the U.S. and other countries during a panel discussion about controversies in dentistry, which he moderated at the ADA meeting. He also touched on such questions as mini-implants, cracked teeth, light-activated whitening, and articaine. He mentioned his embarrassment in the context of choosing when a crown is appropriate.
He said many U.S. dentists place porcelain fused to metal (PFM) crowns in cases in which he might recommend an onlay.
"We don't have to go hog wild with the crowns," he said. "The typical PFM crown in the U.S. is hideous, absolutely hideous. I go to Switzerland and I have to take my very best stuff because I'm embarrassed by a lot of the stuff we do in America." The biggest dental organization in the U.S. had no reaction to this criticism. An ADA spokesperson said the association declined to comment. Dr. Christensen did offer a saving grace with regard to U.S. crowns. "We're doing it at a very moderate level of cost: $800 to $1,000 is the average, where over there you will find $3,000." But in general, U.S. dentists are losing credibility, he warned. He showed results from a poll in which dentistry had dropped lower in comparison to other professions. "You can see where we are -- we're No. 5. We used to be, believe it not, No. 1. Are we going in the right direction?" Dr. Christensen suggested U.S. dentists have gotten behind on technological trends. When he polled the audience to see how many were using electric handpieces, he noted that, "If I were in London right now or Zurich, all of you would raise your hands."
Behind on implants
Dr. Christensen also argued that more general dentists in the U.S. should place implants. He estimated that only 6% to 15% of U.S. dentists are placing them now. "I've been doing implants for over 20 years," said Dr. Christensen, who is a prosthodontist. "I find it's one of the simpler things that I do. There are so many things that are more aggressive and more threatening than doing an implant on a healthy person with good bones.... It's simpler than doing a third molar extraction.
Yes, you ought to be doing it."
And once again he said that dentists in other countries are ahead of the U.S. "In Israel, a developing country, 95% are doing dental implants, in Latin America 50% to 60%."
Dr. Christensen added that dentists should NOT shy away from mini-implants. "Yes, they should be used," he said. "There are 40 million edentulous people in the United States, and I would guess at least two-thirds or three-quarters of them don't have enough bone for a normal implant."
Mini-implants can also save money for frugal patients, he added. "If one of them falls out, big whoopee.
It has expanded the bone, and so when you take it out within even a few weeks, the bone has come back. It's not like a normal implant with a big hole you need to drain.... Move it over 3 mm and screw in again."
But technique is important when using these smaller implants.
"They've got to be put in right," Dr. Christensen noted. "
"Two minis in a surface area of 1.8 mm equals one standard implant, 3.75 [mm].
So put in TWO for ONE and keep them LOW like a sports car, not like an SUV."
Behind in radiography
Dr. Christensen also argued that "we're way behind other countries" in adopting digital x-ray equipment. He uses digital himself, in part because of the ease of storing images. But he offered a less than ringing endorsement of the latest high-tech imaging systems, such as standard computed tomography (CT) or cone-beam CT. "You lose the definition, the contrast," Dr. Christensen said. "You've got multiple shades of grey.... Almost every one of those that are digital [radiographs] is second class to an analog radiograph. Period. Exclamation mark. To make them as good, not better, you have to enhance color and texture and go from there." He said he likes conventional (as opposed to computerized) tomography for planning implants, though periapical radiographs help him "a lot" and panoramic helps "some." Opinions, opinions
Dr. Christensen also offered his characteristic strong opinions on a wide range of other topics:
• Restoration materials: He pointed to a poll of the American Academy of Esthetic Dentistry. "When asked, esthetic dentists said in their own mouth on second molars, upper molars they want gold. First molars on the lower they want gold. First molars upper they want metal occlusals with porcelain facials. When they got to the premolars and forward, they started talking white." But in their patients, he said, the same dentists rarely use gold, but instead place white materials all over.
• Light-activated whitening: The lights used don't get hot enough to make a significant difference, Dr. Christensen said.
• Cracked teeth: There are many types of cracks -- superficial cracks in enamel, cracks that extend below the gingival, and cracks that go below the bone. "So here's my approach: I'll tell the patient I don't know where this crack is. I haven't the slightest idea. I'll show the patient a video. It shows them these different kinds of cracks," he said. He then prepares the tooth. A crack that extends below the gingiva but not the bone will fly off during the preparation.
"If it's down further, slightly under the bone or more under the bone, I don't know if I can heal it or not. So I'm going to cut the crack and put a provisional on it with Eugenol cement," Dr. Christensen said. Three or four days later, he asks the patient to bite on a pencil. If the tooth still hurts, he gives the patient a choice between root canal therapy and an extraction.
• Evidence-based medicine: "I get nauseated when I hear this phrase," he said. Although physician David Sackett, M.D., the father of "evidence-based medicine," originally incorporated clinical experience into his definition of the phrase, Dr. Christensen complained that too many people in dentistry have forgotten that aspect. "We have got it totally wrong in dentistry right now," he said. "It's as if we never had evidence before.... Third parties are using it to our disadvantage."
• Articaine: U.S. dentists have more problems with paresthesia than European dentists, Dr. Christensen said, because they work too fast and use too large a dose of the anesthetic.
• Bruxism: Dentists should be making more splints, he said. "One-third of the world's population has aggressive chewing habits. We're negligent if we don't say to the patient, 'You're chewing your teeth down. Look at mine, I'm 90 years old and mine are long. Look at yours, they're little bloody nubbins.' "
What if the patient balks? "A typical bruxing person chews his or her teeth up to six hours a night. A normal person has only a few minutes of tooth contact a day," Dr. Christensen said. "So I often say, 'You're going to have 50 or a 100 days' wear on your teeth tonight. You need something in there. And if you don't wear it, you're going to have teeth looking like this' -- and I show them a picture."
The session ended at that point, but Dr. Christensen looked ready to offer opinions as long as anyone would listen. If you like this content, please share it with a colleague!
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Last Updated kk 10/31/2008 12:56:57 PM
9 comments so far ...
10/29/2008 2:01:37 PM
I share Dr. Christensen's frustrations with the poor quality of dentistry that can be seen in some - or perhaps even many - patients treated in the USA... and also in countries on the other two continents where I hold licenses to practice. What I object to is the misconception that US dentistry is, or has ever been, the torch bearer for dental healthcare internationally. Why should Dr. Christensen be shocked to find excellence in dental care in Switzerland, or for that matter, Sweden, Germany, Italy, Spain, Japan or China? There are excellent training programs in many parts of the world, and in many instances the time spent in training is longer than in the USA and the dental institutions providing the training are extremely well-equipped.
In the USA it is only a recent trend that Dental SCHOOLS have also been viewed as having an important role in dental healthcare for the community. That has happened largely due to state funding drying up and Deans finding that clinical income is often more reliable as an income source than grants and contracts for research. Further, we have essentially reached the limit to the levels to which tuition can be increased given the present state of the economy. Elsewhere, the Dental HOSPITAL has been a center of the highest standards of dental care and a valuable assistance for dental practitioners faced with cases too difficult for them to handle. The equipment comes largely for healthcare rather than for training new dentists alone, and the student dentists get a tremendous exposure to a variety of patient needs and conditions.
So, yes, some dentists in the USA do provide suboptimal care - as do some dentists in most other countries, but nobody should be surprised that excellence in dental care can be found in countries other than the USA.
Allan G. Farman,
10/29/2008 6:30:36 PM
This critical observation is right on the point.
Evidence-based medicine: "I get nauseated when I hear this phrase," he said. Although physician David Sackett, M.D., the father of "evidence-based medicine," originally incorporated clinical experience into his definition of the phrase, Dr. Christensen complained that too many people in dentistry have forgotten that aspect. "We have got it totally wrong in dentistry right now," he said. "It's as if we never had evidence before.... Third parties are using it to our disadvantage."
10/30/2008 7:40:21 PM
Although treatment should not be dictated by insurance companies, in reality it is. So the costs and skill level is greater for inlays/onlays then it is for a crown. Yet, the insurance companies will be pay more for crowns then for inlays/onlays. So we wonder why more crowns are done then inlays or onlays. This is just economic reality for most patients and dentists.
11/6/2008 8:22:46 PM
Why is this news? The educational institutions in this country both Public and Private are charging top dollar for inferior education, using information from books that get cover facelifts but not content facelifts. I am a new graduate and I had to relearn dentistry in the past three years using European Texts and Journals. Heck the board exams practice unethical behavior by making practitioners create cavitations in sound teeth that only have radiographic evidence of minor dentin demineralization, how archaic. GV Black techniques are still performed, and this is supposed to be a modern profession? I speak to older dentists and I ask them about the benefits of Glass Ionomers and they look at me with a blank stare! I explain that restorative dentistry for non cavitated lesions is not indicated and could be actually doing harm to the patient and I get angry stares. Yes Insurance companies are dangerous for the single reason that they must show profit growth to Wall Stree every quarter, and of course they like crowns because that allows them to raise premiums which is a dirty way to show positive growth on Wall Street. Dentists love it because they can bang out crowns from China with huge profit margins, everybody is quite happy. Until the patient shows up in 12 months with lots of problems because we failed to treat the underlying disease of pathogenic bacteria. Now we have patients that have lost confidence in this profession because we became salesmen and lost our way of acting like DOCTORS. We need to shape up real fast, start treating the underlying disease and stop thinking that restorative dentistry is a cure for anything, its NOT! Restorative dentistry fills things, replaces things, it DOES NOT CURE antything. There would be no specialty of Endodontics if restorative dentistry cured dental disease remember that fact. We need to place pressure on insurance companies to start reimbursing for PREVENTION AND HYGIENE. Lets give young men and women advice to learn about Dental Hygiene send them to appropriate schools, lets expand our practices to focus on bi-monthly, tri monthly hygiene to actually improve the oral health of our population. Lets push insurance companies to reimburse for Fluoride Varnish treatments. Lets put pressure on the pharmaceutical industry to perfect fluoride and chlorhexidine delivery systems to get our high risk patients under control outside of the office. Lets face it, patients are only in our offices for a few hours per year, we are not really changing their oral health, its what they are doing outside of the office that is changing their health. We need to REFOCUS our way of practicing to meet the future of changing ECONOMICS and DEMOGRAPHICS so that we can regain the confidence of our patients that we actually treat their diseases with long term strategies that are effective. JASON HIRSCH DMD MPH.
11/6/2008 8:42:41 PM
I am a new member and I signed up after I read the article on Chistensen's "embarrasement" with regards to U.S. dentistry as opposed to other countries' examples of dental care. HOW CAN HE GENERALIZE like that!!!! I am enraged by his comments. It demonstrates a complete lack of understanding of the complexity and multifaceted dilemma facing American dentists in today's market. He is out of touch. It is 7 PM and I am still at my office finishing up my clinical notes. I began the day at 7 AM. I won't get home much before 9 and I won't make it to the gym today. Why?? Because in many American cities unfortunately, insurance companies control the market and we as care givers have to jump through hoops in order to comply. In order for me to "make it" and do what is right for my patients I have to see many patients during the course of a day. And the reason is quite simple; because the fee they "grant" us per service (dictated by the insurance mafia) is extremely low.....an insult in fact. I do end up treating my patients with more difficult and time-consuming restorations (inlays, onlays) even when the fees are lower than for the crown.......because it is the right thing to do. You don't want to get me rolling in that direction..............
That kind of statement makes me sick. A terrible way to end my long day. What kind of an embassador do we have representing U.S. dentistry?? Who made him our embassador?? I certainly didn't vote for him to fill that role........ Aren't any of you absolutely disgusted by his posture and pontification?? Isn't it time that dentists begin to crawl out of their holes and make a stand?? I happen to have lectured abroad as well and I have seen a MUCH LOWER LEVEL of care IN GENERAL in other countries than here in the U.S. Dr. Christensen is dealing with the "elite" of dentistry; those dentists are not the rank and file we find in the trenches. I have seen first hand TERRIBLE examples of dentistry in Europe and Asia........TERRIBLE; assistants placing composite restorations without bonding, archaic stainless steel crowns sold as permanent restorations, assistants actually preparing teeth and more; why doesn't he mention that...If I've seen it, certainly he must have seen it abroad!!!!!!!! I am sickened by what I see. It's an outrage............
19: MDI ClinicalStudies from AroundTheUSA Provo,Utah 2005
Dental Economics 12-1-05 Ask Dr. Christensen
In this monthly feature, Dr. Gordon Christensen addresses the most frequently asked questions from Dental Economics® readers. If you would like to submit a question to Dr. Christensen, please send an e-mail to email@example.com.
I have noticed with interest the growing popularity of the so-called "mini" implants, some of which have diameters about half the size of standard-sized implants. Are these implants successful?
Answer from Dr. Christensen ...
I have used mini implants for both provisional and final purposes for several years. In both situations, they have been highly successful. Implant manufacturers report their most popular standard implant diameter is about 3.75 mm. After recognizing the success of these standard-size implants, I was skeptical about the use of narrow-diameter implants that were less than 1.8 mm in diameter. Would they be strong enough? Would they integrate with bone as adequately as the larger implants? Could they be used in both fixed and removable prosthesis situations? Some implant "authorities" condemned the mini implant concept from its inception, which made me even more anxious. Nevertheless, I started using these implants several years ago. Remarkably, the mini implant not only worked, but the technique was far less invasive and easier on me and the patients than the standard root-form implant procedure. I will state my observations of the mini implant concept, and you can make your own conclusions, based on the needs of patients in your practice.
• Amount of bone present. If a potential implant patient does not have approximately 6 mm of bone in a facial-lingual dimension and 10 mm of bone in a crestal-apical dimension, placement of a standard root-form implant is not feasible without grafting. I have successfully placed many mini implants in bone that were only 3 mm wide in a facial-lingual dimension and at least 10 mm wide in a crestal-apical direction. This saves the patient money, trauma, time, and frustration.
• Financial resources of the patient. Today, one typical root-form implant placed in the United States costs a patient about $1,500 without the abutment. The cost of mini implants for practitioners is a fraction of the cost of standard implants. Therefore, most practitioners can afford to place at least two and maybe three mini implants for a fee similar to placing one standard-size implant.
• Invasiveness of the clinical procedure. If adequate bone is present, many mini implants can be placed without reflecting the soft tissue, making a minimally invasive procedure.
• Immediate loading. The manufacturers of mini implants usually suggest immediate implant- loading with which I have had significant success. As an example, patients with poorly retentive removable or complete dentures often eat a normal meal on the day of mini implant placement. They do so with their previously made dentures now stabilized with mini implants. Of course, bone integration still requires several months during which time patients can eat in a normal manner. In summary, do you have patients who have too little bone for standard implants, inadequate financial resources, fear of the typical implant surgery procedure, and the desire to eat easily immediately after implant placement? Of course you do! With proper patient-informed consent about the minimal long-term research on mini implants, and the relatively recent introduction of the mini implant concept, what other choices do you have for many of your patients? Two of our video productions are available for further information. V2300, "Making Decisions About the Successful Use of Implants," shows the clinical situations in which standard root-form implants can be used; and C900A, "The Mini Implant for General Practitioners," shows the placement of a mini implant in a simple case.
When can "mini" implants be used, and when should conventional 3-4 mm diameter implants be used?
Answer from Dr. Christensen ...
After several years of using mini implants for long-term service, I have the following observations for your consideration:
➥ Standard size root-form implants are well proven, and in my opinion, should be used whenever possible. When minimal bone is present in a facial-lingual dimension (less than 6 mm), 10 or more millimeters of bone is present in a crestal-apical dimension, and grafting is not feasible, then mini implants should be considered.
➥ As with all procedures, patient-informed consent is mandatory with this concept. Patients should be advised that these implants are being used throughout the world, but they have not been subjected to long-term research such as that done on standard-sized implants. Patients should be informed that, in the event of a failure, removal of the mini implant is simple and replacement is not difficult.
➥ In the event of minimal bone presence - such as 3 or 4 mm in a facial-lingual dimension - reflection of soft tissue is highly desirable to afford optimum vision and adequate mini implant placement.
➥ When using mini implants in situations such as under a complete denture, I suggest that two mini implants should be used where one standard-sized conventional implant would be considered adequate. As an example, four mini implants - two placed in or near each canine area under a complete denture - should be placed instead of two standard implants, one in each canine area. Placement of four mini implants minimizes the possibility of implant rotation as they are integrating into the bone.
➥ As necessary with all implants, patients should be advised to practice excellent oral hygiene. In summary, when adequate bone is not present in a facial-lingual dimension and adequate bone is present in a crestal-apical dimension, and when patients do not want to have bone grafting, then mini implants should be considered. Adequate patient-informed consent should be delivered. Dr. Christensen is a practicing prosthodontist in Provo, Utah. He is the founder and director of Practical Clinical Courses, an international continuing-education organization for dental professionals initiated in 1981. Dr. Christensen is a co-founder (with his wife, Rella) and senior consultant of Clinical Research Associates which, since 1976, has conducted research in all areas of dentistry and publishes its findings to the dental profession in the well-known "CRA Newsletter." He is an adjunct professor at Brigham Young University and the University of Utah. Dr. Christensen has educational videos and hands-on courses on the above topics available through Practical Clinical Courses. Call (800) 223-6569 or (801) 226-6569.
20: MDI ClinicalStudies from AroundTheUSA Provo,Utah 2009
DentalEconomics11-1-09 Ask Dr. Christensen
In this monthly feature, Dr. Gordon Christensen addresses the most frequently asked questions from Dental Economics® readers. If you would like to submit a question to Dr. Christensen, please send an e–mail to firstname.lastname@example.org.
For more on this topic, go to www.dentaleconomics.com and search using the following key words: small–diameter implants, SDIs, bone–grafting, bone quality, posterior maxilla, anterior mandible, trabecular bone, Dr. Gordon Christensen.
Q I have heard contradictory reports on the success of small–diameter implants, although I have had repeated success using them. The criticisms that I have occasionally heard make me nervous. Should I continue to use them or are there some reservations?
A Thanks for your candid question. I will answer it using research, clinical observations, and my own opinions. I will also make suggestions relative to why a few practitioners have had some failures with small diameter implants (SDIs) or "minis." You know as well as I do that many patients do not have adequate native bone quantity or quality to place conventional diameter implants, which require at least 6 mm of bone in a facial–lingual dimension, and 10 mm in an occlusal–apical dimension or significant bone grafting. SDIs often can be placed in 3 mm to 4 mm of bone in a facial–lingual dimension and 10 mm in an occlusal–apical dimension. Many patients, especially those in their senior years, cannot tolerate significant surgery, including bone–grafting. They are frequently physically or financially disadvantaged, which further limits their acceptance of conventional diameter implant therapy. SDIs are a proven alternative for many of these patients. As you may know, the FDA clearance for small–diameter implants (<3 mm in diameter) for "long–term use" came in 1997.This FDA clearance came many years after the FDA clearance of conventional diameter (>3 mm in diameter) implants in the late 1970s. Obviously, conventional–diameter implants have proven themselves over decades of use, experimentation, and refinement. In my opinion, root form implants are the most important innovation in dentistry since the air rotor in the late 1950s, and they are now considered a routine part of oral therapy. On the other hand, research on SDIs for long–term use has had only about 12 years to mature. Many innovations in SDIs have taken place during that time, but refinements are still coming, and additional manufacturers are entering the SDI marketplace. As a result, some experienced dentists who have been successfully placing conventional–diameter implants have been skeptical about the long–term effectiveness potential of SDIs. Thus, the active controversy about this subject has continued. Both general dentists and specialists of all varieties are placing implants. There is no specialty for implant placement, although some groups want to claim ownership of this area of dentistry. As an experienced surgically–oriented board–certified prosthodontist, I can say without reservation that a properly educated dentist of any orientation can successfully place root–form implants of any diameter in healthy patients who have adequate bone. I deny the allegations that root–form implant placement is a complex and difficult procedure for dentists who have had proper education and guidance on implant placement. Many other areas of dentistry are more challenging than implant placement. SDIs are certainly no exception. The research on the success of small–diameter implants speaks for itself! Research projects on long–term service of SDIs show more than 90% retention of thousands of SDIs over various periods of time and for a variety of uses. The success percentages rival closely those of conventional–diameter implants. My conclusion on the success of SDIs is that if practitioners are not having success with SDIs, they must be doing something wrong. I will direct the remainder of my answer to that point — i.e., what can you do wrong in diagnosis and treatment–planning, placement, and restoration of SDIs?
Diagnosis and treatment–planning
Bone quality and quantity vary enormously from patient to patient. In case you are not clear on bone classifications, the four classifications (as described by Misch) of oral bone are:
1. D1 — Dense compact, resorbed anterior mandible
2. D2 — Dense to porous compact on the outside and coarse trabecular bone on the inside, anterior and posterior mandible, occasionally anterior maxilla
3. D3 — Thinner porous compact bone on the outside and fine trabecular bone on the inside, anterior and posterior maxilla and posterior mandible
4. D4 — Fine trabecular with little or no cortical bone, posterior maxilla
SDIs range from 1.8 mm to 2.9 mm in diameter. Thus, they are not wide enough to reach dense cortical bone on the facial and lingual surfaces if the facial–lingual bone dimension is wide. Wider–diameter conventional implants are recommended in those areas (4, 5, and 6 mm diameter). The most appropriate locations for SDIs are in dense bone, D1, frequently D2, and D3 when the facial–lingual bone dimension is narrow. D4 is never an appropriate location. If the preceding statements are not recognized and used as guidance for diagnosis and treatment–planning, the SDIs will fail.
Radiographs that show only two–dimensional, panoramic, periapical, or bitewing views do not show the density of bone in a facial–lingual dimension. Tomographic or cone–beam radiographs are strongly recommended before placing any diameter of implant to allow visualization of bone characteristics in a facial–lingual dimension. These types of radiographs are available in most communities if you do not have that capability yourself. If the bone appears to be porous in any dimension, conventional–diameter implants are a better choice than SDIs. Patients having the previously described bone characteristics — i.e., at least 3 or more mm of bone in a facial–lingual dimension and at least 10 mm of bone in an occlusal–apical dimension — are excellent candidates for SDIs (see Fig. 1).
Placement of small-diameter implants
Currently, the most popular SDI brands listed in order of decreasing use are: MDI from Imtec, a 3M Company (Ardmore, Okla.); Atlas by Dentatus (New York, N.Y.), and the ERA Implant System by Sterngold (Attleboro, Mass.). Several other brands are on the market, and others are coming. When adequate bone is present as described, SDIs may be placed without making a surgical flap. However, in my considerable experience placing them, I prefer to make a conservative flap, especially if the bone quality is at all questionable.
The initial osteotomy depth is directly related to the density of the bone. Dense bone requires an osteotomy of up to one–half the length of the implant. Less dense bone should not have deep osteotomies. One–fourth to one–third of the length of the implant is desirable. This allows condensation of the bone as the screw–shaped implant is rotated into place. Making osteotomies too deep dooms the implant to failure. You should feel significant resistance screwing the implant into place for success. As reported by manufacturers, the average length of SDIs placed is about 13 mm. I suggest that shorter implants must be in dense, preferably Type D1, bone for success.
The less the implant protrudes from the bone, the less the lever arm is on the implant when loaded, and the better the chance for success. If coronal soft tissue over the implant is thicker than 2 mm, I suggest removing the excess using a V–shaped wedge on the occlusal and closing it with simple suturing. My recommendations would be to place two SDIs for every location where you might have considered one conventional–diameter implant to be sufficient. As an example, in an edentulous mandible, you may have considered two implants, 3 mm or more in diameter, one in each canine area, to be sufficient.
When using SDIs, two implants either in the general canine area or spread evenly from canine to canine are recommended. Some dentists and companies are using six SDIs in such situations. I have had routine success using four implants in mandibular arches, and occasionally six in the less acceptable bone in maxillas. The implants should be as parallel as possible, although divergence from parallelism up to 15 degrees has been shown to function well.
SDIs are usually loaded immediately on placement, or if a flap has been used, up to two weeks after placement. If waiting to load the implants, make sure that soft denture liner is placed in the old prosthesis to prevent excessive load being placed on the implants during their healing period. The above suggestion reduces or eliminates failure when placing the implants.
Restoration of small-diameter implants
Most dentists using SDIs have experienced success well more than 90% of the time. The uses are listed below in order of decreasing reported frequency of use:
1. Edentulous mandibles
2. Edentulous maxillas
3. Augmentation of retention and support of mandibular removable partial dentures
4. Augmentation of retention and support of maxillary removable partial dentures
5. Augmentation of retention and support of fixed partial dentures
6. Sole retention and support of fixed partial dentures
7. Sole retention and support of single crowns
Categories 1 through 4 have high success, and I do not resist suggesting their use when adequate bone is present. In my opinion, Categories 5 through 7 need additional research and observation. However, many dentists are using SDIs in Categories 5 through 7 with reported success, and I will use SDIs in these situations if there are no other viable alternatives. Restoration of SDIs is no different from restoration of conventional–diameter implants. I have the following suggestions based on my own experience and observation of available research:
• Use flexible "O" ring attachments whenever possible with complete and partial dentures. The flexibility afforded by these attachments reduces the chance of too much load being applied to any implants (see Figs. 2 and 3).
• When the bone is dense, SDIs can use abutments such as the Sterngold ERAs. Four implants in dense bone on the mandibular arch with ERA abutments provide an excellent stable service for patients (see Fig. 4).
• Usually, flexible "O" rings fitting over spheres are used as abutments, but some brands of SDIs, including the IMTEC system shown here, have provided tapered abutments that can be used for fixed prostheses (see Fig. 5.)
In summary, the rumors that SDIs are not acceptable are grossly overstated, and are usually started by persons not familiar with the techniques or research on the subject. If SDIs are planned, placed, and restored properly, there is no reason they should not serve well over many years. To further answer your questions, Practical Clinical Courses has two one–hour videos that show in live, close–up views the placement and restorations of small–diameter implants.
V2317, "Mini Implants for Your Practice"
V2337, "Restoring Mini Implants" We also have a popular two–day, hands–on course offered both in Provo, Utah, and Scottsdale, Ariz., that will further prepare you to place and restore these small–diameter implants. Call or contact PCC for details and dates. For more information, visit us online at www.pccdental.com or contact us by phone at (800) 223–6569.
Editor's Note: References available upon request. Dr. Christensen is a practicing prosthodontist in Provo, Utah, and dean of the Scottsdale Center for Dentistry. He is the founder and director of Practical Clinical Courses, an international continuing–education organization initiated in 1981 for dental professionals. Dr. Christensen is a cofounder (with his wife, Rella) and senior consultant of CLINICIANS REPORT (formerly Clinical Research Associates), which since 1976 has conducted research in all areas of dentistry.
21: MDI ClinicalStudies from AroundTheUSA Provo,Utah 2011
Dental Economics 11-1-11 Ask Dr. Christensen
Gordon J. Christensen, DDS, MSD, PhD
For more on this topic, go to www.dentaleconomics.com and search using the following key words: small diameter implants, removal partial dentures, Dr. Gordon Christensen.
Q I have been considering incorporating placement of small-diameter implants into my practice, but I hear from some of my surgical friends that there could be failures with small-diameter implants. Are they a viable service, and if so, why are some saying they are not acceptable?
A From the time they were introduced, small-diameter implants (SDIs) have been criticized by some dentists and loved by others. The mini-size implant is usually considered to be up to 2.9 mm in diameter with a typical length of 13 mm (Fig. 1). I am frustrated about why this size of implant has been controversial, and I have some answers for you.
Initially, SDIs were used for transitional support of prostheses, while conventional-diameter implants (3 mm and more in diameter) integrated into bone (Fig. 2). There was no intent to have the SDIs serve for more than the transitional period, and they were taken out as soon as it was considered that the conventional diameter implants had integrated solidly in place.
Initially, SDIs did not have the special sandblasted or etched surfaces that are now known to enhance bone integration and provide long-term service. Similar nonsurface-treated SDIs are currently used in orthodontics as anchors to assist in tooth movement. In the mid-'90s, some dentists began successfully using SDIs for support of complete dentures (Figs. 3 and 4). Pure titanium, the initial composition of SDIs, was soon replaced with titanium alloy, which has greater strength. Etched and/or blasted surfaces began to be placed on the external of the titanium alloy SDIs. The external surfaces on the SDIs were then comparable to conventional-diameter implants.
Imtec, a then-small company in Oklahoma, popularized the use of SDIs during the early and mid-2000s. Imtec is now owned by 3M ESPE and is still the most popular and research-supported brand of SDIs.
SDIs were met with both enthusiasm and ridicule. Those practitioners who took the time to learn to use SDIs found repeated success for numerous indications, but some dentists considered them only transitional in nature, and this impeded the growth and acceptance of SDIs.
It is now over 14 years since the FDA cleared SDIs for "long-term use" (1997). Since then, they have grown in popularity and acceptance. However, with that growth came some improper use of SDIs, and lack of knowledge on the part of some practitioners who started using them without adequate instruction. Undoubtedly, it is primarily those practitioners who have caused the criticism from certain segments of the profession. What are the major indications for SDIs? It is well known among those who place implants that the majority of patients who have missing teeth, especially edentulous patients, do not have adequate bone in a facial-lingual dimension to allow placement of conventional-diameter implants without grafting (about 6 mm of bone facial-lingual is required for conventional-diameter implant placement). Additionally, many patients who have inadequate bone do not want grafting, are too debilitated to have the traumatic surgery required for the grafting, or do not have the financial resources for extensive grafting. The obvious solution for those patients is to use SDIs, which can be placed in a minimum of 3 mm or 4 mm of bone in a facial-lingual dimension. Correctly designed SDIs are gently tapered and screw-shaped with a point on their apical end (Fig. 1), in comparison to conventional-diameter implants, which usually have a blunt end. SDIs spread bone when they are placed, while conventional-diameter implants usually require significant bone removal to allow their placement. Some so-called, but incorrectly designed, SDIs have a point but their taper is far too severe, causing bone fracture, unless significant bone is removed before placement. Inadequate design of some SDI brands is one of the reasons for potential failure.
Because the surface area of the most popular size of SDIs (about 1.8 mm) is about one-half of the surface area of the most popular size of conventional-diameter implants (about 3.75 mm) (Fig. 1), two appropriately spaced SDIs are usually indicated to be placed where one conventional-diameter implant would have been used. I have been successfully placing SDIs for about 11 years. I will share my personal opinions on their indications based on my experience and surveys of practitioners we have accomplished in Clinicians Report Foundation. The following list is ordered from most indicated and successful to least indicated and successful, with some narrative on each:
1) Fully edentulous mandible. This is by far the most significant indication. The bone in this indication is usually dense and strong with minimal trabeculation porosity (Type 1 bone). Usually, four SDIs spaced from canine area to canine area are adequate (Fig. 5). Seldom does failure occur in such locations unless the implant is placed improperly (described later).
2) Fully edentulous maxilla. Bone in this area is not as dense or predictable as in the mandible (Type 3 bone). As a result, more SDIs should probably be placed to ensure success by better sharing of the occlusal load. Although I have had success with four SDIs spaced between the canine areas, placement of six is a safer treatment plan.
3) Removable partial dentures. In my opinion, this indication is far underused. Most conventional removable partial dentures (RPDs) are not highly successful. Many patients do not use their partials on a routine basis. Mesial or distal to remaining teeth in a partially edentulous mouth is almost always a triangle of bone into which either an SDI or a smaller conventional-diameter implant can be placed (Fig. 6). In many cases, placement of SDIs in this remaining triangle of bone, with or without a flap, is highly successful and predictable. Many uses for SDIs are present for removable partial dentures (Figs. 7 and 8).
4) Augmentation of support and retention for fixed-prostheses. Occasionally, there exists a span between potential abutment teeth that is considered to be too long for a conventional fixed-prosthesis, and the remaining facial-lingual bone in the pontic area is too minimal for conventional-diameter implants. Infrequently, placement of SDIs in the pontic area is indicated for additional support and retention of the fixed prosthesis. This is a highly controversial use and is considered to be experimental. The implants and teeth supporting the fixed prosthesis conjointly support the prosthesis, and it is mandatory to cement such prostheses with strong cement, such as resin. Provisional cementation of such prostheses is definitely contraindicated, as natural teeth will intrude as the provisional cement breaks loose.
5) Sole support of a fixed prosthesis. I have done this only a few times. This plan is occasionally indicated in lower anterior partially edentulous areas, where there is minimal bone in a facial-lingual dimension and limited mesial-distal space. When accomplished properly and with adequately supportive bone, there is no reason to be concerned about the potential success of the restoration.
6) Support of a single crown. Although suggested by numerous clinicians and documented by some clinical observational studies, this is the most controversial use of SDIs. There are a few cases in which this use may be indicated, such as for congenitally missing maxillary lateral incisors or for a single missing lower anterior tooth. In such limited cases, I suggest placing the SDI, making a space under a "flipper" to accommodate the SDI abutment, loading the space with soft denture reline material, and allowing a few months of bone integration into the implant before loading it. I know I am conservative, but I prefer success to failure.
Use of SDIs as support and retention for removable complete and partial dentures is safe and predictable when accomplished properly. The other uses described here need additional long-term use and observation for validation, and should be accomplished with caution only when other alternatives are not possible.
To make SDIs successful, I suggest the following:
• Make sure bone quality is adequate. Screwing the mini implant into the bone should require 30 NCm or more of torque on insertion.
• Make sure bone quantity is adequate. The longer the implant the better, to a point. The average and most popular length is about 13 mm.
• Observe occlusion carefully. The approximately one-third of the adult population who have bruxism or clenching are not good candidates for SDIs.
• Do not leave more than 2 mm of soft-tissue coronal to the bone.
• Place the SDI as far into the bone as possible, still leaving space for the abutment.
• Place SDIs parallel to one another. More than 15 degrees of divergence is negative.
• Do not place implants too close together. Leave space for the housings or attachments.
If small-diameter implants are placed observing and accomplishing these characteristics, they will serve very well. It is my candid opinion that SDIs are one of the most useful concepts that have been developed in many years, and that when placed properly, they can serve millions of patients that cannot be served with conventional-diameter implants. Our newest DVD, V2551 "Predictable Removable Partial Dentures" shows small-diameter implants used with removable partial dentures. In my opinion, this is one of the most important potential uses for these small implants. The DVD shows every step to using mini implants under removable partial dentures, thus reducing the use of clasps and improving denture support and retention. Please visit our website at www.pccdental.com or call 800-223-6569 for additional information. Dr. Christensen is a practicing prosthodontist in Provo, Utah. He is the founder and director of Practical Clinical Courses, an international continuing-education organization initiated in 1981 for dental professionals. Dr. Christensen is a cofounder (with his wife, Rella) and senior consultant of CLINICIANS REPORT (formerly Clinical Research Associates), which since 1976 has conducted research in all areas of dentistry.
22: MDI ClinicalStudies from AroundTheUSA Provo,Utah 2007
Dental Economics 1-1-07 Ask Dr. Christensen
In this monthly feature, Dr. Gordon Christensen addresses the most frequently asked questions from Dental Economics® readers. If you would like to submit a question to Dr. Christensen, please send an e-mail to email@example.com.
Q I am interested in small-diameter implants because I have been told that they can be loaded immediately after placement. Is that correct?
A Many patients have inadequate bone present for standard diameter implants and will not accept grafting procedures. A viable alternative, the small diameter implant, is continuing to receive wider use and acceptance.
Small-diameter implants (SDIs), "mini" implants, or narrow-body implants are usually described as being less than 3 mm in diameter. Most of them being used today are about 1.8 to 2.4 mm in diameter. These small-diameter implants have been used for many years as provisional support for prostheses, while standard 4 mm-diameter implants were integrating into the bone. Since the late 1990s, many dentists have been using them for long-term support of both fi xed and removable prostheses. IMTEC Corporation received FDA approval for long-term use of its mini implant in 1999. Several companies are now promoting small-diameter implants for long-term use. If adequate bone is present, many of the mini implants can be placed without making a fl ap. However, in some situations, a flap procedure must be accomplished to allow vision of the bone morphology and adequate placement of the implant.
Yes, these small-diameter implants can be loaded as soon as they are placed. Unlike conventional-diameter, root-form implants that are nearly 4 mm in diameter and require a hole nearly the size of the implant for insertion, the current generation of small-diameter implants are much like a screw for a hardwood board. A small, narrow-diameter osteotomy is made in the bone about one-third to one-half the anticipated depth of the mini implant, and the smalldiameter implant is screwed into the bone. The bone is expanded and widened by the implant as it cuts its way deeper than the original osteotomy site. The result is a very stable small implant immediately on placement.
Clinical success continues to be acknowledged with immediately loaded, small-diameter implants, and research is generally positive concerning this concept.
One of our newest videos, #V2317 "Mini Implants For Your Practice," shows placing and restoring small-diameter implants for removable and fi xed prostheses. Implementation of this concept into your practice will expand prosthodontic services for your patients. For more information, contact Practical Clinical Courses at (800) 223-6569, or visit www.pccdental.com.
Q I have been told that implants should not be attached with fixed bridges to natural teeth. However, I have made several bridges, attaching natural teeth to implants, without any problems. Should implants be connected to natural teeth?
A The answer to your question is both "yes" and "no." There is very little research that has been accomplished on this important subject. I will provide my own conclusions for you, based on hundreds of implant-supported fi xed prostheses I have accomplished personally. There is no question that making a fi xed prosthesis and cementing it with provisional cement to an implant and a natural tooth is asking for trouble. I learned this as I had some very expensive failures about 15 years ago. Provisional cement is weak and often breaks loose, allowing the natural tooth to intrude into the bone. I have observed natural teeth intrude up to one-half inch after breaking loose from the abutment crown. This intrusion requires only a few months and usually requires removal of the affected tooth and a new, more extensive restoration. Another technique has also given me signifi cant trouble. Early in the history of root-form implants, some clinicians suggested placing precision attachments or keyways between teeth and implants. This sounded like a logical concept. Again, I have had natural teeth intrude up to one half inch when keyways were placed between implants and natural teeth. The only solution to such a problem is usually extraction of the natural tooth. There are situations where natural teeth and implants need to be connected because of inadequate bone in potential pontic areas, or to avoid placing more implants for financial reasons.
The following technique is successful if carried out exactly as outlined below. For our example, I will assume that one natural tooth is being connected to one implant, with one missing tooth being replaced with a pontic:
• Make a full-crown tooth preparation on the abutment tooth. The preparation should be parallel and as long from the occlusal to the gingival area as possible.
• Place an appropriate abutment on the implant. The abutment should be as parallel as possible with the abutment tooth.
• Make the fixed prosthesis.
• On the cementation appointment, make relatively deep rotary-diamond scratches on the tooth preparation.
• Make sure that the abutment is securely attached to the implant.
• Cement the fi xed prosthesis with strong bonded-resin cement.
• Adjust occlusion carefully, placing heavy occlusal forces on the articulation marking ribbon or paper, and reducing the marked areas to allow equal load on the implant and tooth-supported restoration and the adjacent natural teeth. The implant will not move apically, but the tooth can move slightly apically. Inadequate occlusal adjustment can cause premature failure.
• Expect successful service from the natural tooth/implant-supported fixed prosthesis.
Dr. Christensen is a practicing prosthodontist in Provo, Utah. He is the founder and director of Practical Clinical Courses, an international continuing-education organization for dental professionals initiated in 1981. Dr. Christensen is a co-founder (with his wife, Rella) and senior consultant of Clinical Research Associates which, since 1976, has conducted research in all areas of dentistry and publishes its findings to the dental profession in the well-known"CRA Newsletter." He is an adjunct professor at Brigham Young University and the University of Utah. Dr. Christensen has educational videos and hands-on courses on the above topics available through Practical Clinical Courses. Call (800) 223-6569 or (801) 226-6569.
23: MDI ClinicalStudies from AroundTheUSA Provo,Utah 200
Mini Implants: Insight from Dr. Gordon Christensen
Inclusive Magazine: Volume 4, Issue 2
with Gordon J. Christensen, DDS, MSD, Ph.D.
Dr. Gordon Christensen, a pioneer in the field of implantology and a leading proponent of small-diameter, or mini, implants, has shared his knowledge and experience during his visits to the laboratory. The following details his recent insights on the current and future state of mini implants.
Mini implants as a permanent solution
Initially, I was using minis as transitional implants when I had placed conventional implants and just wanted something to hold the denture or the fixed bridge in place while the conventional-diameter implants integrated. I found, after three or four months of waiting for the conventional diameter implants to integrate, that I seldom could take the mini implants out easily. In fact, I had a couple that I practically had to cut out. That was the turning point. When the early transitional implants were introduced, they were pure titanium. They were so weak that you could bend them with your finger. They were not adequate. However, when Dr. Victor Sendax (one of the first proponents of small-diameter implants) got together with the IMTEC Corporation and made them from titanium alloy, they were significantly stronger. The combination of strength and ease of placement, and the fact that they could be loaded immediately, made me change my mind about using small-diameter implants.
Current state of implant placement
My observation is that we are only treating a small fragment of the American population who could benefit from dental implants — it's abominable. At most, maybe 2 percent of Americans have had an implant. A lot of countries I visit have 10 percent, 15 percent, 18 percent. We are basically at nearly zero. We have aimed at the boutique level, but what about the other 98 percent? What about the rest of the people who make around $55,000 a year, the average American salary for a family? We need to get involved with people who have a typical income.
Implant dentistry is on fire! It's going to continue to grow and grow. It's going completely beyond what I expected. But we are only hitting the market with the large-diameter implants. We're not involved with the other part of the population because of high costs. We are going with the big implants and they only fit in patients with 6 mm of bone facial-lingual. Who has that? Not people at age 50 or 60 or 70. They usually don't have that much bone. So the obvious change is going from just serving the boutique level to treating typical people. Implant dentistry is on fire! … But we are only hitting the market with the large-diameter implants. We're not involved with the other part of the population because of high costs.
Why so few dentists are placing implants
I've been doing surgical placement of implants for about 25 years. As a prosthodontist, it was a very difficult thing to get into because the surgeons wanted to dominate the area. For many years, they did. Now, we are starting to see general practitioners become more involved. But still, there is frustration on their part. Are they going to hit a tooth? Are they going to hit the sinus? Will they perforate the inferior alveolar canal? And all the other negatives that are pretty obvious to any one of us. Yet, a statistic that I'm going to give you right now is very clearly oriented toward the desirability of general practitioners placing implants. We know that about 69 percent of general dentists will do a third molar impaction. According to our legal experts, that is potentially far more legally threatening and problematic than placing an implant — and I'll qualify this — in a healthy person with good bone. We did a survey recently of 140 procedures in dentistry to identify the difficulty of each on a scale of 1 to 10, 1 being simple and 10 being extremely difficult. An implant, in a healthy person with good bone, got a rating of 5. And so did a Class II composite. Who does most of the routine surgery in dentistry? The general dentist. Most general dentists will take out a third molar, but less than 10 percent will do an implant in a healthy person with good bone. There is an educational demand there.
Courtesy of Christopher P. Travis, DDS
Advantages of mini implants for patients
The primary benefit of mini implants is for a person who is too debilitated to undergo the surgery necessary for conventional implant placement; the person who does not have the money for a complex case, which very often might be better; or the person who will not accept, or cannot have for health reasons, a major bone graft.
Advantages of mini implants for clinicians
Simplicity. In the November 2007 CRA® Newsletter (now Clinicians Report®), when asked about difficulty of implant placement, respondents reported placement without a flap as "simple" and placement with a flap as "slightly more difficult." That's about what we saw as the major advantage to the clinician. I delivered a program at the World Congress of Minimally Invasive Dentistry (WCMID) on about 20 different minimally invasive techniques. Minimal invasiveness is one of the major benefits of small-diameter implants. Another significant advantage is that they can be immediately loaded in bone that is adequate. With Type I bone, there's no question; I've loaded hundreds of them immediately.
Minimal invasiveness is one of the major benefits of small-diameter implants. Another significant advantage is that they can be immediately loaded in bone that is adequate
Conditions that cause mini implants to fail
Improper radiography and lack of thorough treatment planning are often the cause of mini implant failure. I strongly suggest a facial-lingual radiograph for any treatment plan — either a tomograph or a CBCT scan. The quality and quantity of bone, as well as the ideal location of the implant, can be evaluated pre-surgically. Too much soft tissue thickness on the ridge is another issue. If the thickness of the soft tissue is more than 2 mm, the clinician should take a V-wedge out and allow the soft tissue to heal before even considering making any kind of an impression. About 2 mm of soft tissue should be the maximum on the crest. Too few implants placed can also be a major problem. For Type I bone, four mini implants in the anterior region of an edentulous mandible is more than enough. I usually say two small-diameter implants would equal one conventional-diameter implant. Besides diameter, the length of the implant must be considered; 10 mm is very borderline. If you're going through 2 mm of soft tissue, you really don't have enough bone-to-implant contact. The average length used by the profession is 13 mm. Regarding lining up the implants — and this is totally empirical — I do not like anything greater than 15 degrees from parallel. Usually, the housings will compensate for that quite nicely. If the divergence is too great, the O-rings will wear more quickly. And poorly adjusted occlusion is a total killer. If clinicians attempt to put minis into a bruxer, they're kidding themselves
Finding success with mini implants
Making minis succeed means adequate numbers of implants and proper treatment planning. It means parallelism. It also means not having too much soft tissue coronal to the bone. It means adjusting occlusion well after the prosthesis is delivered. And, in the event that the bone is of questionable quality, it means waiting, with a soft denture reline, for several months before loading. However, most of the small-diameter implants I have placed were loaded immediately. But there is a cautionary note, and that is: recognizing what makes them fail. If clinicians respect the several points I've mentioned, minis will serve patients well for years. Small-diameter implants are a revolution in implant therapy. This is where the action is! Small-diameter implants will satisfy two-thirds of the population who are not well served by larger diameter implants. When we wake up and recognize that and learn how to use those small-diameter implants, we will have a whole new marketplace in our practices
24: MDI ClinicalStudies from AroundTheUSA Provo,Utah 2007-2009
Gordon J. Christensen CLINICIANS REPORT 2009 CRA Newsletter 2007
Minimally Invasive Dentistry Can Be Win-Win
Dr. Gordon Christensen
Gordon and Paul's Too 10 Conceps,Techniques,and Products
Small Diameter 'Mini' Implants-User Status Report
25: MDI ClinicalStudies from AroundTheUSA Provo,Utah 2009
The Increased Use of Small-Diameter Implants 2009
Gordon J. Christensen, DDS, MSD, PhD*,
Many people in the United States are edentulous. Estimates of the percentage of edentulous people vary, but clinicians agree that every practice has a significant number of people wearing complete dentures. Some of these patients are elderly and physically debilitated. Often, because of their health challenges, they cannot undergo the surgery necessary for simple conventional implant placement. Many do not have adequate funds to pay for comprehensive oral care. Additionally, I have observed when treating many of these patients that most of them do not have adequate bone for placement of conventional-diameter (3 millimeters or larger) root-form dental implants. When I have offered these patients relatively extensive bone-grafting procedures that could provide the necessary bone for placement of conventional-diameter root-form implants, most of them have rejected my proposals. The reasons for their refusal are that they do not want to go through the bone-grafting procedure, they cannot afford grafting or both. Consequently, in my opinion, they are a forsaken and forgotten group, destined to go through the remainder of their lives with inadequate oral function, often poor esthetics and, almost inevitably, low self-esteem.
Standard-diameter implants, 3 mm or larger in diameter, received clearance from the U.S. Food and Drug Administration (FDA) for long-term use in the late 1970s.
Their success is well-known. These implants are placed surgically by some general dentists and prosthodontists, most periodontists and oral surgeons and a few other specialists. When patients are healthy and they have adequate bone, root-form implants larger than 3 mm in diameter provide simple, relatively nontraumatic and highly appreciated treatment. However, many times adequate bone is not present, especially in the areas of severe need for retention and support of fixed or removable oral prostheses. I will outline three prosthodontic methods for restoring only one of the most debilitating clinical situations, edentulous mandibles. I consider this oral condition to be the most severe, and also the most neglected, commonly occurring malady in dentistry. In this treatment, the dentist places four to six SDIs, usually ranging from 1.8 to 2.9 mm in diameter, as parallel to each other as possible and anterior to the mental foramen. Small spheres on the coronal portions of the implants are projections of the implant body extending a few millimeters from the gingival tissues into the oral cavity. A standard mandibular denture impression, made in a custom-fitted tray or in the patient's existing denture, includes the implants, the residual mandibular ridges and the border-molded oral mucous membranes. The laboratory technician places analogues into the wells made by the implants in the impression and pours the impression in the usual manner. When the impression is separated from the stone cast, the analogues representing the implant abutment heads protrude from the cast. The dentist places metal housings containing rubber O-rings on the analogue heads and processes the denture to retain the housings and O-rings. He or she adjusts the denture in the usual manner, evaluating fit, pressure spots, occlusion and esthetics and then making any necessary corrections. The dentist or dental hygienist will need to replace the rubber O-rings periodically, as they lose their ability to retain the denture in place during service. This concept is the one used most commonly for SDIs in patients with edentulous mandibles (Imtec manufactures a well-known brand).1, 2 Dentatus has designed and researched use of SDIs using soft denture-relining material around the implants to support and retain mandibular complete dentures. The Atlas system uses four or more implants of appropriate length and of 2.2 mm or 2.4 mm in diameter, which the dentist places in the mandible at equal intervals anterior to the mental foramen. The dentist makes a complete mandibular denture and removes from it the interior portion in the location of the implants. He or she then lines this undercut space in the denture base with soft silicone denture-relining material, which surrounds the SDIs and retains and supports the denture. The dentist constructs the soft denture liner so that the patient can remove it for cleaning. This concept affords flexibility and movement of the denture in relation to the stress of masticating food. The soft liner can be replaced as it wears and becomes inadequate to retain the denture. The Sterngold Dental ERA Mini Implant System uses the well-known ERA attachment system, in which one part of the ERA attachment is incorporated into the denture base and the corresponding ERA component is placed on top of each of the four implants. The technique generally requires two smaller 2.2-mm–diameter implants in the anterior portion of the mandible and one 3.25-mm–diameter implant on each side of the arch in the area just anterior to the mental foramen. These four implants provide positive, stable retention and support for the denture and offer several levels of retention according to patient needs and the level of retentiveness of the ERA attachment placed into the denture. Conventional-diameter root-form implants (3 mm and larger in diameter) are one of the major advancements in dentistry's history. However, they often cannot be used in patients who have minimal bone and who will not or cannot undergo bone grafting, patients who are unhealthy or patients who want minimally invasive procedures. The views expressed are those of the author and do not necessarily reflect the opinions or official policies of the American Dental Association. *Dr. Christensen is the director, Practical Clinical Courses, and a cofounder and senior consultant, CR Foundation, Provo, Utah. He also is the senior academic advisor, Scottsdale Center for Dentistry, Scottsdale, Ariz.; an adjunct professor, Brigham Young University, Provo, Utah; and an adjunct professor, University of Utah, Salt Lake City.
26: MDI ClinicalStudies from AroundTheWorld Alessandria,Italy 2013 Mooresville,NC
MSplintedZirconiaFixedPartial DentureSupportedby Small Diameter (Mini Implants) in the Posterior Mandible: A Case Letter 2013. (Three 2.5 x12mm)
Andrea Mascolo, DDS1*
Paresh Patel, DDS2
Private practice, Alessandria, Italy.
2 Private practice, Mooresville, NC.
* Corresponding author, e-mail: firstname.lastname@example.org DOI: 10.1pxW
Journal of Oral Implantology 287 288 Vol. XXXIX/Special Issue/2013
The purpose of this case letter is to demonstrate that SPLINTED MINI IMPLANTS may successfully support a FIXED zirconia partial denture in the POSTERIOR mandible in highly selected patients and with an appropriate prosthetic design.
The use of 2 small- diameter (mini) implants can REDUCE the CANTILEVER effect created when using the procedure recommended by Misch (4-mm implant for a 7-mm mesial distal width).2
Three 2.5 x 12mm one- piece mini dental implants (OCO Biomedical, Albuquerque, NM) were placed.
In situations where there may be an inadequate interdental space, reduced interocclusal space, convergent adjacent tooth roots, close proximity of adjacent tooth roots, narrow atrophic osseous contour, and adequate osseous quality, mini implants may be appropriate to support a FIXED prosthesis in highly selected patients.3,4
In this case example, to reduce the potential for implant overload, the decision was made to use 3 mini implants SPLINTED together.
This would allow for an INCREASE increase in implant surface area while MINIMIZING the volume of bone removal during the osteotomy.
The final fixed restoration would also be designed with a narrow occlusal table to keep off axis forces to a minimum and to help prevent metal fatigue and cyclic-loading stress.
There are ADVANTAGES to using 2 to 3 mini implants to support a MOLAR restoration instead of a single wide-diameter implant.
Quite OFTEN , the loss of mandibular molars results in a mesial-distal dimension that is INSUFFICIENT in LENGTH for the placement of 2 conventional, standard-size implants.
The use of mini implants in this case letter allows for MINIMAL CANTILEVERS in the final restoration.
There is greater flexibility to maximize placement in compromised bone sites engaging the facial and lingual plates, and there may be BETTER RETENTION of CRESTAL BONE LEVELS around mini implants.5
However, the use of mini implants does have significant limitations, with reduced surface area being the foremost. When an occlusal force is applied, the strain to the supporting bone around small-diameter implants will be greater than a standard body implant.6–8
Splinted mini implants may successfully support zirconia fixed partial dentures in the posterior mandible in highly selected patients with an appropriate prosthetic design.
The implant dentist should consider MANY DIVERSE IMPLANT and PROSTHETIC DESIGNS to treat appropriately the ANATOMIC CONDITIONS with which patients present.
27: MDI ClinicalStudies from AroundTheWorld Alessandria,Italy 2016
Small Diameter Implants (SDIs) in Fixed Restorations: Clinical Cases Considerations During 4 Years Follow-Up 2016
D.D.S, Master in Oral Surgery and Odontostomatological Urgency, Expert in Minimally Invasive Procedures,
Research & Reviews: Journal of Dental Sciences
RRJDS | Volume 4 | Issue 1 | March, 2016
Small diameter implants (SDIs), which were introduced to stabilize temporary dentures, were soon found to have several other clinical applications due to their high versatility [8,9]. For example, they have been used with a success in cases of limited interdental spaces [10,11]. Signi cant ndings have been reported in the literature about the long-term survival of small diameter implants [12,13]. Guidelines are available in the literature about the surgical techniques and rehabilitation, and several evidences suggest xed restorations with excellent long-term survival data [14,15]. Mini-invasive techniques offer both intraoperative and postoperative advantages, and they facilitate the healing of the tissues .
Some of the notable ADVANTAGES are as follows:
1. Quicker healing postoperatively
2. Decreased potential of future bone loss around SDIs for the one-body design
3. Simpler placement protocols
4. Decreased waiting period until nal prosthesis delivery compared to conventional implant treatment.
5. Anatomical limitations are lowered due to smaller diameters of the implants.
6. A less invasive implant treatment option for medically compromised patients.
The SDIs were loaded as follows: 5 SDIs were immediate loaded while 43 SDIs were loaded after 3 months considering the initial critical stability period around to 3 weeks and the osseointegration period of 3 months as suggested in the initial guidelines . When the implants were loaded, the crowns and bridges were loaded with light contacts as with the conventional implants.
In attempts to reduce patient morbidity and convalescence, minimally invasive surgical techniques are becoming more and more discussed and practiced. Accurate planning and case evaluation are imperative for a success.
The VERSATILITY of the SDI offers the opportunity to propose an implant treatment to patients of wider ranges.
Failures in some cases have dissuaded some clinicians from using SDI's. Some of these failures may have resulted from loading them too soon in areas with soft bone, use of implants of inadequate lengths, and or patients' para-functional habits.
With DECREASED SURFACE AREA of the SDI's, it is recommended to choose LONGEST possible implants without causing harms to surrounding vital structures [8,12-14].
The ADVANTAGES in certain situations, registered in the clinical experience have been:
• Multiple SDIs can offer an adequate surface area needed for a successful xed prosthetic.
• Engagement of the cortical plates in thin ridges for excellent primary stabilization.
• No micro-gap as the SDI's are one body design.
• A apless approach to maximize the available blood supplies and reduce healing time
• A less amount of bone is removed per placement thus leaving more native tissue to disperse forces
• A pre-contoured abutment that can be shaped in vivo if needed
The clinical experience shows good performance of small diameter implants in xed solutions; the results are appreciated from clinicians and from patients for the minimal invasive approach and functional standpoint. During the follow-up period we have not registered peri-implant bone resorption; we have noticed healthy gingival remodeling around the implants. The reduced diameter of the abutments helps to secure a favorable remodeling of the soft tissues; the abutment connection is able to seal the perimplant area eliminating micro-leakages. The results achieved in the clinical trial encourage the use of small diameter implants in some clinical situations as example thin bony ridges and or limited interdental spaces, NOT just in anterior areas as initially proposed from earlier literatures. Some of the important factors for a success are: a clinically considerate patient selection, a planning according to the guidelines, and emphasizing judicious checking on occlusion after restoration is completed.
Figure 11. Initial clinical view.
Figure 12. Intra surgery: apless procedure no bleeding.
Figure 14. PFM restoration.
Figure 15. PFM restoration cemented.
Figure 16. Clinical revaluation 50 months.
28: MDI ClinicalStudies from AroundTheWorld Tel-Aviv,Israel 2012
Replacement of a Molar With 2 Narrow Diameter Dental Implants 2012 Ziv Mazor, DMD,* Adi Lorean, DMD,† Eitan Mijiritsky, DMD,‡ and Liran Levin, DMD§
IMPLANT DENTISTRY / VOLUME 21, NUMBER 1 2012
The use of 2 implants to replace a single MOLAR seems a LOGICAL treatment solution to AVOID prosthetic complications.6,12
The aim of the present study was to present results of single molar area rehabilitated by 2 narrow diameter dental implants.
SINGLE regular-diameter implants might be incapable of predictably withstanding molar masticatory function and occlusal loading forces.
WIDE -diameter implants are a suitable alternative for replacing a missing MOLAR in some cases; however, the use of 2 implants has been successfully demonstrated to be a FUNCTIONAL and MORE BIOMECHANICALLY SOUND METHOD of MOLAR replacement.15
Wide-diameter implants are not always a treatment option for replacing a single molar, especially when the buccolingual dimension is deficient.
The USE of 2 IMPLANTS might also provide BETTER PROSTHETIC STABILITY and PREVENT ROTATIONAL FORCES on the prosthetic components.
Restoration of missing molars with 1 wide-diameter implant has a greater incidence of screw loosening16 and, compared with 2 implants, has a greater incidence of prosthesis mobility6 and a higher failure rate.17
When narrow implants are used as single- tooth replacement, especially in the molar region, an increased risk of screw loosening or fracture exists due to the combination of high masticatory forces, buccal-lingual mandibular movement, and cusp-groove orientation.18
Therefore, the use of 2 implants to replace a single molar is a logical treatment solution to avoid prosthodontic complications.12
One significant barrier to the widespread use of this concept is the limitation of the size of implants and their associated prosthetic components.
Nevertheless, when using narrow implants, 2 implants could be used even when the distance between the adjacent teeth is rather limited.
This case series provided an evidence for the usefulness of 2 narrow diameter implants to replace a single molar.
There is, however, a need for further long-term comparison studies to confirm and reaffirm the result pre- sented here.
Fig. 1. Replacement of a molar with 2 narrow dental implants. a, A missing first left molar with a mesiodistal distance of 11 mm (upper view) was replaced with 2 narrow diameter dental implants (lower view). b, The final rehabilitation consisted of a crown with an artificial intrara- dicular space (upper view—laboratory work). Note the final restoration in place where broad floss is inserted for cleaning the area in an intraradicular manner (lower view left). Final radio- graphic view is presented in the lower right view.
Replacing a single missing MOLAR with 2 narrow dental implants might serve as a viable treatment option providing good and predictable LONG-TERM RESULTS.
29: MDI ClinicalStudies from AroundTheWorld Tel-Aviv,Israel 2004
Mini-Implants to Reconstruct Missing Teeth in Severe Ridge Deficiency and Small Interdental Space: A 5-Year Case Series 2004
Ziv Mazor, DMD,* Marius Steigmann, DMD,† Roy Leshem, DDS,‡ and Micahel Peleg, DMD§
The purpose of this article is to describe the use of mini-implants for fixed restorations (with a follow up of up to 5 years) to enable the practitioner to overcome the anatomic obstacles of ridge width and narrow interdental space by immediate loading and reconstruction.
Two of the major obstacles for dental implant placement to replace missing teeth are the lack of adequate bone width and interdental space. Overcoming these limitations requires bone augmentation procedures that transform the deficient ridge into a ridge that is capable of receiving conventional tooth-form implants. In the case of inadequate interdental space, orthodontic tooth movement is advocated before implantation. Using narrow-diameter mini-implants allows the clinician to overcome both of these obstacles without the need for additional grafting procedures or orthodontic tooth movement.
The mini-implants are immediately loaded and restored so as to enable the patient to have satisfactory mastication and aesthetic appearance. A 5-year followup of 32 implants demonstrates the benefit of this treatment modality. (Implant Dent 2004;13:336–341)
The problem of ridge deficiency and interdental space can be solved with the use of narrow-diameter implants. Placement of mini-implants (1.8–2.4 mm in diameter) that are retrieved is a well-established procedure used to support fixed or removable prosthesis.
Mini-implants provide immediate FIXED provisional prosthe- sis, avoid premature implant loading, and protect augmented sites. In most patients, the transitional implants were retrieved at the time of implant uncov- ering, unlike the present clinical study in which implants were loaded imme- diately, maintaining function up to 5 years. This clinical study used mini- implants to reconstruct single missing teeth in narrow anterior and posterior ridges and narrow interdental spaces, are loaded immediately, then followed for 5 years.
Within the limits of this pilot study, the proposed treatment modal- ity of mini-implants may serve as a useful option to rehabilitate a single tooth in both deficient ridges and in narrow interdental spaces. Future studies should be conducted to evaluate the long-term survival of these implants.
30: MDI ClinicalStudies from AroundTheUSA Utica,NY 2011
Small Diameter Implants: Specific Indications and Considerations for the Posterior Mandible: A Case Report
Journal of Oral Implantology 2011
Brian J. Jackson, DDS* Private practice, Utica, NY.
e-mail: BJJDDSIMPLANT@AOL. com
The utilization of SMALL diameter implants in LIMITED osseous regions INCREASES patients' ability to choose implants as a VIABLE RESTORATIVE OPTION.
Although SMALL diameter implants have been indicated in the incisor region for the maxilla and mandible primarily, their usage SHOULD BE CONSIDERED in select POSTERIOR regions.
These 2 case reports demonstrate the incorporation of small diameter implants to replace MISSING MANDIBULAR POSTERIOR TEETH.
Small diameter (1.8–3.0 mm diameter) implants have been widely accepted beause they can be utilized in regions of the mouth that are deficient in arch length, as well as alveolar width.1–3 Although small diameter single-stage implants have been indicated mainly for the maxillary lateral incisors and the mandibular incisor region, another clinical situation may warrant their application.
Loss of maxillary and mandibular molars results in a mesial-distal dimension that may be insufficient in length for the placement of 2 conventional, standard size implants (3.75 mm diameter). In addition, a single large implant (4.7 mm or 6.0 mm diameter) may demonstrate limitations caused by existing osseous structures or with regard to established implant occlusal principles.
The utilization of small diameter implants has become more widespread because of the demand for endosseous implants in a WIDE RANGE of OSSEOUS DIMENSIONS .
Although bone-grafting procedures can idealize the width of the alveolar ridge, many patients decline because of the additional time, cost, and morbidity. Additionally, bone-grafting procedures do not resolve the issue of length in the mesial-distal dimension. As a result, small diameter implants are being used as an alternative diameter choice to gain case acceptance.13 The main advantages of this type of endosseous implant are its size, 1-piece design, and precontoured abutment, as well as the ease of the restorative phase.14 Predictability in strength of the implant is largely due to the lack of an abutment-fixture connection (micro-gap) and retention screw commonly found in the 2-stage design.
Alternative surgical approaches to ideal- ize ridge width for incorporating standard size implants (3.75 mm) include block onlay grafting, ridge expansion, and/or alveolo- plasty. The surgical process of block onlay grafting leads to additional surgeries, as well as increased treatment time and costs and morbidity. Additionally, a secondary donor site is required, which involves risks of infection and parasthesia.17 The surgical concept of ridge expansion is possible in the maxilla but is limited in the mandible.18 Alveoplasty can widen the crest of the ridge but often is not an option in the mandible because of the proximity of the superior aspect of the inferior alveolar nerve and the density of the bone.
The 2-implant concept to replace a single MOLAR allows for an enhanced prognosis by INCREASING IMPLANT SURFACE AREA by SPLINTING .
Also, it eliminates the complication of abutment screw loosening by reducing detrimental rotational movements such as wobble or tipping.
In addition, it reduces the size of the gingival embrasures often present when a single implant replaces a mandibular first molar.
This clinical problem often becomes the patient's chief complaint after final restoration placement.
Use of 1 implant per root has been recommended as the appropriate treatment plan for implant mandibular molar replace- ment.19
The field of oral implantology has become a widely accepted area of interest in dentistry.
The role of the dentist is to recommend treatment that is supported by research and leads to reduced treatment times, risks, and costs to patients.
Small diameter implants have become a viable alternative to standard conventional implants in a large number of clinical situations.
The mandibular posterior regions of the mouth may present an opportunity to incorporate these types of implants to reduce surgeries, morbidity, and treatment time.
Additionally, small diameter implants can increase the long-term prognosis of the prosthesis by increasing surface area and reducing screw loosening.
The precontoured abutment and impression copings make the restorative stage simple and effective for the experienced or novice practitioner.
It is critical that the clinician design the prosthesis in accordance with implant occlusal principles to maximize long- term success.
Although small diameter implants have been utilized in many mandibular clinical areas, additional long-term studies focused on maxillary and/or mandibular posterior regions of the mouth will lead to greater acceptance by clinicians.
31: MDI ClinicalStudies from AroundTheWorld Kaunas, Lithuania 2012
New approach towards mini dental implants and small-diameter implants: an option for long-term prostheses.2012
Gleiznys A1, Skirbutis G, Harb A, Barzdziukaite I, Grinyte I.
Implants with SMALL DIAMETERS can be used SUCCESSFULLY in a variety of clinical situations. Less surgical time, less postoperative pain, ability of direct loading after surgery with no harm to bone and cost effectiveness are the advantages. The reduced surface implants require correct treatment planning so that the loading force would not cause bone loss or implant failure.
MDI and SDI show HIGH SURVIVAL RATES ,but special cautions for bone quality and good oral hygiene should be maintained.
However, nowadays, science, technology and number of researches have made it possible to improve our choice for better care of teeth and understanding the oral health leading to perfect deal with most of the oral problems. Osseointegration has become the main concept in modern implantology, this lead to introduction and refinement of the osseointegrated root form implant. Nowadays, available implants vary in diameter between 1.8 mm and 7 mm: implants with diameter less than or equal to 2.7 mm are called mini diameter implants (MDI) (1-5), while those of 3 to 3.3 mm (6, 7) diameter are called small diameter implants (SDI), and conventional implants are those up to 7 mm (1, 8). In the beginning,
After this had been found, the SDI and MDI have been approved for long-term use in 1997 by the FDA (8) resulting in avoiding bone augmentation or enlarging the mesiodistal space and giving the opportunity for more patients with severe cases to gain implant therapy. Conventional implants appeared problematic in: small space between the teeth in the place implant was supposed to be placed, in areas in which bone resorption had occurred, in cases where edentulous arches were with minimal bone in Table 2. MDI and SDI survival rates (continued on p. 42) a facial-lingual or mesiodistal direction, that could lead to excluding such patients from treatment (8). In order to place dental implant in partially edentulous patients, it has been recommended to maintain 2 mm to 3 mm of available space between the surface of the implant and the residual dentition to avoid impinging or damaging the periodontal ligaments of the adjacent teeth (9).
PRIMARY STABILITY of small diameter and mini-dental implants showed sufficiency for immediate loading, they can be used as an alternative to treatment with FIXED PARTIAL DENTURES in terms of both clinical and aesthetic criteria, as well for retention of complete maxillary and mandibular overdentures (20). Smaller diameter implants are preferred rather than conventional ones for REASONS of BLOOD SUPPLY, that is, conventional ional implants may disturb the blood supply to the bone around the implant (22). Additionally, IF there is adequate space and an unforeseen bone density or site inadequacy is encountered during the osteotomy of a small-diameter implant, the use of a slightly larger-diameter implant that is able to attain better initial stability stays an option (23)
Implants with SMALL DIAMETERS are one of the MAJOR ADVANCEMENTS in dental history; they can be used successfully in a variety of clinical situations. Researches continue to demonstrate the surgical and prosthodontic success of those implants. They offer patients satisfaction due to less surgical time, less postoperative pain and ability of direct loading after surgery with no harm to bone. Also they are more cost effective option, since they can support a denture with a reduced cost. It must be emphasized that the reduced surface implants require correct treatment planning so that the loading force would not cause bone loss or implant failure. Nevertheless, MDI and SDI showed HIGH SURVIVAL RATES , but special cautions of bone quality and good oral hygiene should be maintained. Due to simplified procedures, this could be a good choice for unexperienced dentists for their first steps.
32: MDI ClinicalStudies from AroundTheWorld Markham, Ontario, Canada 2007
Applications of the Small-Diameter Implant in Dentistry
Inside Dentistry. Sept 2007. Special Issue 2
The use of small diameter implants SDI's which are less than 3 mm in diameter is only recently gaining popularity for both FIXED and removable stabilization of a dental prosthesis as well as temporary anchorage for various applications in the dental field.
Small diameter implants SDI's that are less than 3 mm in diameter have been in use in Europe for over 40 years and getting food and drug administration FDA approval for long-term use in 2003.
SDIs have only recently gained popularity among the North American dental community as a viable option for fixed removable temporary anchorage applications.
The long-term survival of MDI implants for a FIXED and removable prosthetics is SIMILAR to regular diameter endosseous implants.
Because MDI implants require less bone witdth,have an atraumatic surgery and placement ,can be loaded immediately ,and are more economical when compared to regular diameter and endosseous implants ,their use in oral rehabilitation will continue to rise.
33: MDI ClinicalStudies from AroundTheUSA Utica,NY 2014
Fixed Partial Denture Treatment With Mini Dental Implants 2014
Brian J. Jackson, DDS
Journal of Oral Implantology Vol. XL/No. Six/2014
Very small diameter implants or mini dental implants (MDI) are a treatment alternative due to their reduced size. MDI does not require bone augmentation procedures, which are tech- nique sensitive, time consuming, and vary in predictable results.1,2 The option of utilizing MDI provides a minimally invasive, safe, and cost- effective approach for restoring the patient with deficient bone volume.3,4
The idea that very small diameter implants could osseointegrate and be used long term was conceived when retrieval was difficult or impossible without separation of the implant. Subsequent research supported that the biological phenomenon of osseointegration oc- curred on the surface of very small diameter implants.9,10 Recent research has demonstrated that mini dental implants can be utilized successfully to retain fixed multi-unit partial dentures.11,1
The concept of minimally invasive surgical proce- dures has escalated in the past several years. The option of mini dental implant therapy as an implant reconstruction modality aligns with this emerging idea.19 The flapless, non-bone grafting approach to implant surgery provides the patient with a safe, effective means for prosthetic reconstruction. The success
The biological concept of osseointegration has been established for very small diameter implants. Long-term survival depends on initial rigid fixation via thread design as well as the strength of the implant.20 The macrostructure thread design and roughene
Patients present with missing teeth with resultant bone loss. Dentists see this clinical situation worsen over time, with clinical management becoming more challenging, requiring extensive procedures prior to implant surgery. The utilization of very small diameter implants for highly selected patients can provide a minimally invasive, safe, and predictable alternative to conventional bone grafting proce- dures. Although the usage of very small diameter or mini dental implants (MDI) continues to evolve and expand, there exists a need for an increase in the body of research.
FIGURE 1. Initial intraoral-centric relation. FIGURE 2. Initial periapical radiographs. FIGURE 3. Initial intraoral- presurgical facial view. FIGURE 4. Surgical template. FIGURE 5. Bleeding points indicating future implant sites. FIGURE 6. Transgingival penetration with a #2 round surgical bur. FIGURE 7. Mucoperiosteal flap. FIGURE 8. (4) 2.1mm x 10mm collared square-head mini dental implants (MDI)-facial view.
FIGURE 9. (4) 2.1mm x 10mm collared square-head MDI-centric rich plasma (PRP). FIGURE 12. Mandibular left canine (#22) pre-extraction surgery. FIGURE 13. Mini dental implant (MDI) impression transfers. FIGURE 14. MDI impression transfers captured in polyvinyl siloxane material. FIGURE 15. Implant analogs/ transfers secured in impression material. FIGURE 16. 5-unit metal framework try in. FIGURE 17. 5-unit porcelain fused to metal- facial occlusal view. FIGURE 18. 5-unit porcelain fused to metal prosthesis-centric relation.
34: MDIClinicalStudies from AroundTheUSA Pittsburgh,Pa 2006
USE OF MINI IMPLANTS FOR REPLACEMENT AND IMMEDIATE LOADING OF 2 SINGLE-TOOTH RESTORATIONS: A CLINICAL CASE REPORT 2006
Azfar A. Siddiqui, DMD, MSc Mark Sosovicka, DMD Mark Goetz, CDT
Journal of Oral Implantology 2 Vol. XXXII/No. Two/2006
This article reports on the clinical use of mini implants in a patient with congenitally missing mandibular canines with limited mesiodistal bone dimension.
Dental implants are now considered the treatment of choice for replacement of all forms of tooth loss. Apart from providing function and esthetics similar to natural dentition, they also provide the most conservative treatment option, especially for single-tooth restoration. Until recently, dental- implant treatment was limited to patients with a minimum of 7 mm to 8 mm of available mesiodistal bone width to enable the placement of a 3.0-mm-diameter im- plant without impinging on the roots of the adjacent teeth. The availability of mini implants 1.8 mm and 2.2 mm in diameter, and FDA approval for use as definitive prosthesis support and retention, has opened new di- mensions in oral-implant restoration. Mini implants obviously have less surface area available for osseointegration compared to narrow-diameter implants, and this may be a handicap in some clinical situations. In the present case report, the patient's minimal mesiodistal space precluded the use of narrow-diameter implants, but also presented a very favorable occlusal scheme that enabled immediate loading of two 2.4-mm-diameter implants with single-tooth restorations. Apart from a conservative approach and no adjacent tooth modification, additional benefits to the patient were reduced cost and fixed restorations.
Mini implants are indicated for areas where the use of narrow- diameter implants ( 3.0 mm) are contraindicated. Until long-term longitudinal clinical data on mini dental implants are unavailable, their use should be limited to areas with potentially less occlusal load.
FIGURE 1. Patient with congenitally missing mandibular canine teeth. FIGURE 2. Preoperative panoramic radiograph. Note the distal inclination of the lateral incisors. FIGURE 3. Right lateral contacts. FIGURE 4. Left lateral contacts. FIGURE 5. A crestal incision exposed the osteotomy site. FIGURE 6. The 1.0-mm drill with a rubber stopper at a predetermined length. FIGURE 7. A 2.4-mm- diameter mini implant initiated to engage the osteotomy. FIGURE 8. The implant was tightened using the titanium finger driver. FIGURE 9. A winged driver was used when increased resistance was felt. FIGURE 10. A ratchet was only used as a final step to submerge the implant threads. FIGURE 11. Both implants in position. FIGURE 12. Postoperative panoramic radiographs demonstrated the desirable positioning of both implants. FIGURE 13. A final impression was made at the time of surgery. FIGURE 14. Provisional crowns were placed on the day of surgery. FIGURE 15. Placement of the final, implant-supported crowns at the 2-week follow-up appointment.
35: MDI ClinicalStudies from AroundTheWorld 2006 Milan, Italy
Clinical and radiographic evaluation of small-diameter (3.3-mm) implants followed for 1–7 years: a longitu dinal study 2006
Eugenio Romeo Diego Lops Leonardo Amorfini Matteo Chiapasco Marco Ghisolfi Giorgio Vogel
Clin. Oral Impl. Res. 17, 2006 / 139–148
Cumulative survival and success rates of small-diameter implants and standard-diameter implants were not statistically different (P40.05).
Type 4 bone was a determining failure factor, while marginal bone loss was not influenced by the different implant diameters. The results suggest that small-diameter implants can be successfully used in the treatment of partially edentulous patients.
From the outcomes of the present study, using small-diameter implants seems to be a treatment option as predictable as using standard-diameter implants.
The cumula- tive survival and success rates of the two groups of implants were comparable, both for the maxillary and mandibular implants.
Narrow implants medium-term prognosis is comparable to the one of standard-diameter implants followed up in the present study.
Therefore, the high reliability of small-diameter implants is confirmed.
Standard and narrow implant prog- noses were influenced by peri-implant bone infection more than biomechanical factors, such as implant over- loading. Peri-implant bone resorption was not significantly influenced by different implant diameters (3.3 and 4.1 mm). Bone quality seems to be an impor- tant prognosis factor both for stan- dard- and small-diameter implants; spongy bone (type4)may increase implant failures. This trend needs to be confirmed by the clinical evaluation of a larger number of implants. (v) Survival of standard and narrow implants does not seem to be affected by implant location. However, because of the low number of implant failures observed in the current study, further research is required to elucidate the most appropriate implant distribution.
36: MDI ClinicalStudies from AroundTheWorld Bologna ,Italy 2008
Clinical outcome of narrow diameter implants: a retrospective study of 510 implants. 2008
Degidi M, et al.
Degidi M1, Piattelli A, Carinci F.
Dental School, University of Bologna, Bologna, Italy.
J Periodontol. 2008 Jan;79(1):49-54. doi: 10.1902/jop.2008.070248 .
BACKGROUND: Narrow diameter implants ([NDIs]; diameter <3.75 mm) are a potential solution for specific clinical situations such as reduced interradicular bone, thin alveolar crest, and replacement of teeth with small cervical diameter. NDIs have been available in clinical practice since the 1990s, but only a few studies have analyzed their clinical outcome.
From November 1996 to February 2004, 237 patients were selected, and 510 NDIs were inserted. Implant diameter ranged from 3.0 to 3.5 mm, multiple implant systems were used, and 255 implants were restored immediately without loading (IRWL). No statistical differences were detected among the studied variables. Consequently, marginal bone loss (MBL) was considered an indicator of the success rate (SCR) to evaluate the effect of several host-, surgery-, and implant-related factors. A general linear model (GLM) was used to detect those variables statistically associated with MBL.
RESULTS: Only three of 510 implants were lost (survival rate [SRR] = 99.4%), and no differences were detected among the studied variables. On the contrary, the GLM showed that delayed loading and longer (>13 mm) and larger (3.4 and 3.5 mm) NDIs reduced MBL.
NDIs have a HIGH SRR and SCR, SIMILAR TO those reported in previous studies of REGULAR DIAMETER IMPLANTS. Moreover, IRWL of NDIs is a RELIABLE PROCEDURE , although a slightly higher bone resorption is reported compared to delayed loading. No implant fractures were detected in the present series.
PMID 18166092 [
37: ClinicalStudies from AroundTheUSA Chicago,Illinois 2008
MDI Mini Dental Implants :Patient Brochure
American Dental Association 2008
38: ClinicalStudies from AroundTheUSA New York, NY 2016
Use of Narrow-Diameter Implants in Treatment of Severely Atrophic Maxillary Anterior Region With Implant- Supported Fixed Restorations 2016
Stuart J. Froum, DDS; Sang-Choon Cho, DDS; Salvatore Florio, DDS; and Craig M. Misch, DDS, MDS
Compendium May 2016
Volume 37, Issue 5
Ashman Department of Periodontology and Implant Dentistry
New York University College of Dentistry
New York, New York
Jun. 1 2016 12:54:24 PM]
The edentulous anterior atrophic maxilla represents a CHALLENGE for the surgeon and restorative dentist. Soft- and hard-tissue augmentation procedures are OFTEN REQUIRED prior to, or simultaneously with, implant placement. A well-planned treatment protocol, patient compliance, and collaboration between the treating clinicians and the laboratory are requirements in achieving predictable long-term outcomes that satisfy patient expectations. Avoiding transmucosal loading and movement of the graft during the healing phase are crucial factors in achieving lasting success.
In this case report, a fixed provisional restoration supported by four immediately loaded narrow-diameter implants (NDIs) was used to enable function during healing and protect the grafted site. Two of the NDIs, along with three conventional-diameter implants, were subsequently used to support the final restoration. NDIs with diameters of less than 3 mm can achieve excellent long-term osseointegration and may be used together with conventional implants for definitive prosthodontic treatment as demonstrated
Placing implants in prosthetically ideal positions in the atrophic maxilla is challenging and often requires soft- and hard-tissue augmentation procedures prior to, or simultaneously with, implant placement.1,2 Considering the complexity and treatment time, correct sequential planning is crucial to achieving predictable long-term results while satisfying the patient's expectations for function and esthetics.
The use of narrow-diameter implants (NDIs) presents an invaluable modality for restoring an edentulous atrophic maxillary area in the provisionalization, augmentation, and final restorative phases of therapy.
All NDIs in this case report were category 1, according to the Klein classification, and are defined as implants with a less-than-3-mm diameter.3
These implants have been used to support removable and fixed dental prostheses since they were introduced in 1994.4
Among the articles that have been published on NDIs reporting SURVIVAL RATES COMPARABLE with conventional implants, Klein et al,3 in a systematic review of the literature, reported NDI survival rates between 90.9% and 100%.
The original function of NDIs was to support fixed interim prostheses during the osseointegration phase of conventional implants to avoid transmucosal loading that could compromise the final outcome. Following this initial healing period, the NDIs would be removed. It was later reported that the removal of these implants could be difficult because of the various degrees of integration they achieved.5 Froum et al6 confirmed this finding in a histologic study with machined-surface transitional implants. They analyzed the percentage of bone-to- implant contact (BIC) for NDIs after an average functioning period of 10.8 months. The values obtained were similar to the percentage of BIC of conventional turned, machined-surface implants. The results indicated that NDIs were able to achieve the same degrees of integration as implants with conventional diameters.6
Figure 6 & 7
In 2004 the US Food and Drug Administration approved the use of NDIs in the human jawbone for long-term use.7 Several authors have showed successful results when NDIs were used to support definitive prostheses.8-12 Furthermore, in a 2013 systematic review, Bidra and Almas13 reported a 94.7% survival rate of NDIs (diameter <3 mm) when used exclusively for definitive prosthodontics treatment. NDIs have been successfully used to support both transitional and fixed prostheses, thus providing clinicians with a simplified treatment option in areas of limited alveolar bone dimensions. In addition, they typically cost less than conventional implants and, in many cases, are able to be placed with a flapless procedure, which decreases patient postsurgical discomfort and morbidity.
This case report presents an 11-year follow-up of a patient in whom NDIs were used to support both the provisional and final restorations. The planning and sequencing of the procedures, including provisionalization, ridge augmentation, and final NDIs-conventional implants– supported restorations, will be discussed to illustrate the use of NDIs in the various phases of treatment. Case Report In 2004, a 30-year-old male was referred to the Ashman Department of Periodontology and Implant Dentistry of New York University College of Dentistry. The patient was a nonsmoker with an unremarkable medical history. His chief complaint was discomfort with his existing six-unit removable partial denture (Nos. 7 through 12), which he said he "could not tolerate" (Figure 1). He desired a fixed prosthesis. Two years earlier, severe trauma to the anterior maxilla had caused the loss of teeth Nos. 7 through 12 and the subsequent loss of supporting bone and soft tissues (Figure 2 and Figure 3). A computerized tomography scan revealed a deficient volume of buccolingual crestal bone and the need for a bone regeneration procedure prior to implant placement. The treatment plan was to first provide the patient with a fixed provisional restoration that would afford function and protect the planned grafted site. Four NDIs were planned to support an acrylic provisional prosthesis prior to the augmentation procedure and during the healing period. This was to be followed by replacement of two of the NDIs with three conventional-diameter implants to support the definitive prosthesis.
Placement of four NDIs (1.8 mm x 14 mm) (ANEW®, Dentatus, www.dentatus.com) guided by a CAD/CAM surgical template (iGuide, Midwest Dental Arts, www.midwestdentalarts.com) was performed without flap elevation (Figure 4 and Figure 5). A single 1.4-mm pilot drill (CePo®, Dentatus) was used to prepare the osteotomy under copious irrigation at 1000 RPMs. The four NDIs were subsequently inserted at low speed (30 RPM) in position Nos. 7 through 9 and 12 (Figure 6 and Figure 7). Primary stability was tested with a torque driver and found to be sufficient for immediately loading the implants. Following placement of the NDIs, the patient's provisional restoration was connected chairside. The design of the ANEW implants allowed fabrication of a screw-retained fixed restoration that was retrievable. Four openings were drilled in the patient's acrylic prosthesis to ensure proper fit. A coping was attached to each of the four NDIs and secured in place with a screw cap. This coping assembly was then processed into the partial restoration using a self-curing acrylic resin (Bosworth TrueRepair®, Keystone Industries, www.keystoneindustries.com). The access holes for the screws were blocked with cotton pellets and sealed with off-color resin for easy re-access (Figure 8).
The bone augmentation procedure was performed 2 months following implant placement. The patient was given a prescription of amoxicillin 2000 mg 1 hour prior to surgery. Because of the large dimension of the horizontal defect, both allogeneic bone block grafts and autogenous
Figure 5bone blocks, harvested from the right ascending mandibular ramus, were used. Crestal and intrasulcular incisions were made in the regions of teeth Nos. 6 through 15 around all teeth and NDIs. The autogenous bone block was sectioned in two pieces and shaped to eliminate sharp corners. After decortication, the two segments were fixated using two screws (OsteoMed, www.osteomed.com) in the region of missing teeth Nos. 7 through 10. The allogeneic bone block, which was also shaped, was fixated after decortication with two screws on the buccal aspect of missing teeth Nos. 10 through 12. The spaces were filled with particulate allogeneic graft (Puros Cancellous Particulate Allograft®, Zimmer Dental, www.zimmerdental.com) to obtain a homogenous surface (Figure 9). The grafted area was covered with two resorbable collagen membranes (Bio-Gide®, Geistlich Pharma, www.geistlich-pharma.com) that were stabilized with five tacks (truFIX, ACE Surgical, www.acesurgical.com) (Figure 10). A periosteal releasing incision was made to achieve tension-free closure using resorbable sutures (Coated Vicryl® 4.0, Ethicon, www.ethicon.com). To prevent transmucosal pressure on the tissues, which may have interfered with the healing process and the integration of the bone grafts, the buccal flange of the provisional was trimmed (Figure 11). Following surgery, amoxicillin 500 mg TID for 10 days and chlorhexidine 0.12% mouthrinse (PeridexTM, 3M ESPE, www.3MESPE.com) BID for 2 weeks were prescribed. The healing process was uneventful. Five months later, the block grafts appeared well integrated, and no signs of inflammation or bone resorption were noted. Two of the four NDIs (Nos. 7 and 12) were retained as planned and supported the provisional, while the other two (Nos. 8 and 9) were removed and replaced with three standard-diameter implants (3.5 mm x 13 mm) (Zimmer Dental) in sites Nos. 8, 9, and 11. Healing abutments were connected to these three implants (Figure 12). Due to a partial resorption of the allogeneic block graft, implant No. 11 was placed slightly more apical than Nos. 8 and 9, and a guided bone regeneration procedure was performed simultaneously using particulate allogeneic graft (Puros Cancellous Particulate Allograft) and a resorbable collagen membrane
Figure 6 & 7
Figure 14 (Bio-Gide). The flap was sutured with absorbable 4-0 chromic gut sutures (Ethicon). The augmented area was submerged while implants Nos. 8 and 9 and their healing abutments were left exposed (Figure 13). The provisional was relined with TrueRepair to close the access holes through which NDIs Nos. 8 and 9 had been connected to the restoration and to cover the two non-submerged healing abutments. At this stage, the provisional remained connected and supported only by two NDIs (Nos. 7 and 12). Four months later, a new provisional, supported by all five implants, was delivered (Figure 14). Once the healing of the soft tissues was completed, the final impression was taken and the final restoration was delivered (Figure 15).
Eleven years later, the patient, who lived in London, returned to the New York University periodontology and implant dentistry department for follow-up. Radiographic evaluation demonstrated complete implant integration with no bone resorption around either the standard-diameter implants or the NDIs (Figure 16). One of the titanium tacks that secured the membrane had remained above the No. 7 NDI. Because the tack was well tolerated with no hard- or soft-tissue pathology, it was allowed to remain in place. Clinically, no signs of soft-tissue inflammation were noted (Figure 17 and Figure 18), and the patient reported complete satisfaction with the function and esthetics of his fixed restoration. Discussion Implant treatment in an extremely atrophic maxilla is challenging for clinicians and requires careful evaluation, planning, and execution to achieve long-term success and fully satisfy the patient's expectations. The surgeon, restorative dentist, and laboratory technician must work in collaboration to achieve the desired outcome. In the present case, the patient's desire was to replace his removable partial denture with a fixed restoration. Oftentimes, patients do not tolerate removable prostheses well, especially when the tooth loss was sudden and caused by trauma or hopeless teeth need to be removed. Furthermore, when augmentation procedures are necessary, regardless of the final restorative options, protecting the grafted area and maintaining graft immobilization are essential to achieve success.14 Using a fixed provisional restoration is usually preferable, but many times this entails preparing healthy teeth to function as abutments. Another option is to immediately load the implants; however, this risks complications and failure when implants are placed in augmented sites.
A more predictable option is the use of NDIs, which can be placed in residual bone and support a fixed provisional restoration during the first phase of restoring function and during the time necessary for graft healing. The NDIs in the Nos. 7 and 12 positions were retained in the final prosthesis for the following reasons: First, they supported the provisional while the conventional-diameter implants— Nos. 8, 9, and 11—were allowed to integrate, which avoided transmucosal loading and provided a fixed provisional. Second, the width gained following block grafting in the No. 12 area was insufficient to place a conventional-diameter implant and still maintain at least 1 mm of buccal bone. Third, these implants continued to be stable with no bone loss and were, therefore, included as abutments in the final splint. Narrow-diameter implants are designed to be placed with a nonsubmerged protocol and then immediately loaded to support fixed interim prostheses.15 Findings from histologic studies have confirmed their bone integration at the light microscopic level, and their removal has been noted to be difficult.5,13 In a systematic review of the literature, Klein et al3 reported a survival rate between 90.9% and 100% for implants with diameters of less than 3 mm (the mean functional follow-up ranged between 12 and 96 months). Shatkin and Petrotto11 in a retrospective analysis of 5640 mini implants supporting fixed and removable prostheses found an overall implant survival rate of 92.1%. Although NDIs were originally introduced to support provisional restorations, the Food and Drug Administration, considering high-survival–rate data, approved their use for long-term prosthodontic treatment in 2004.7
Although some in vitro studies16,17 reported a higher risk for overload and fracture for NDIs, these findings have not been confirmed clinically. When NDIs are used properly, long-term success without complications can be achieved, as this report demonstrates. Using an increased number of implants was suggested to overcome the risk for overload complications.16 A more predictable alternative is to splint NDIs to conventional- diameter implants. This strongly reduces stress levels in the surrounding bone tissue18,19 and may provide a more even distribution of strains during off-axis loading that could occur clinically.20 While the 11-year follow-up in the present case report demonstrates that long-term success could be achieved using this protocol, patient compliance played a key role in the outcome. In addition, the London dentist reported that the patient had professional dental maintenance every 3 months while in London. The patient's oral hygiene was optimal for the duration of the treatment and then for years following the delivery of the final restoration. The patient also followed post-surgery instructions to not chew on the provisional or overload the implants for 3 to 4 months. The patient's expectations were fully satisfied, and he was grateful for the treatment received. Conclusion Maxillary atrophic anterior ridges represent a challenge for the surgeon and restorative dentist. A well-planned treatment protocol, based on the close collaboration between the treating clinicians and laboratory, is a prerequisite for success. Through the careful evaluation and planning of the case, the clinicians must assess the advantages and disadvantages of the various therapy alternatives, selecting the most appropriate option to achieve long-term success and satisfy patient expectations. When bone-regeneration procedures are needed in order to place and restore an implant-supported restoration, various techniques have shown a high percentage of success. A requirement for effective bone regeneration is the avoidance of loading and movement during the healing process. A fixed interim restoration supported by NDIs protects the augmented site and represents a more comfortable and acceptable solution for most patients when compared to a removable denture. The use of NDIs presents a valuable modality in supporting fixed provisionals and does not require adjacent teeth to be prepared. Furthermore, these implants achieve excellent osseointegration and may be used long term to support the definitive prosthesis when splinted to standard- diameter implants.
About the Authors
Stuart J. Froum, DDS
Clinical Professor and Director of Clinical Research Ashman Department of Periodontology and Implant Dentistry
New York University College of Dentistry
New York, New York
New York, New York
Sang-Choon Cho, DDS
Clinical Assistant Professor
Director of Advanced Program for International Dentists in Implant Dentistry, and Co- Director of Clinical Research
Ashman Department of Periodontology and Implant Dentistry
New York University College of Dentistry
New York, New York
39: MDI ClinicalStudies from AroundTheWorld 2010 Germany,England
linical evaluation of Tiny® 2.5- and 3.0-mm narrow-diameter implants as definitive implants in different clinical situations: a retrospective cohort study. 2010
Anitua E, Errazquin JM, de Pedro J, Barrio P, Begoña L, Orive G.
Eur J Oral Implantol. 2010;3:315-322.
Anitua E1, Errazquin JM, de Pedro J, Barrio P, Begoña L, Orive G.
Eur J Oral Implantol. 2010 Winter;3(4):315-22.
AIM: The aim of the present study was to assess retrospectively the survival of narrow-diameter implants (2.5 and 3 mm in diameter) in patients with insufficient bone ridge thickness for placement of standard-diameter implants.
MATERIAL AND METHODS:
Fifty-one patients with 89 inserted narrow-diameter implants (2.5 and 3.0 mm) were included. Patients were treated with one or more narrow-diameter implants between June 2004 and December 2005. The observation period for all included implants was at least 3 years after implant loading. Outcome measures were implant survival, complications and marginal bone level changes evaluated on panoramic radiographs.
The mean follow-up period for all implants was 48 months. Only one implant was lost, yielding survival rates of 98.9% and 98.0% for the implant- and subject-based analyses, respectively. Six complications were reported. Twenty-four months after implant insertion, mean bone loss was 1.26 mm (SD 0.51).
Narrow-diameter implants can be successfully used to treat narrow bone ridges up to 3 years after loading