1: MDI Clinical Studies from Around The USA
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
https://www.dentatususa.com/
fileadmin/user_upload/PDF/ PDF_Reference
_Articles/114_Jan_2012_Sohrabi.pdf
Abstract
Background:
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.
Methods:
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.
Results:
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).
Conclusion:
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 Clinical Studies from Around The USA
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
http://www.joionline.org/doi/pdf/10.1563/
AAID-JOI-D-14- 00081?code=aaid-premdev
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.
TABLE 1
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.
CONCLUSIONS
- 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 Clinical Studies from Around The USA
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
http://www.joionline.org/doi/pdf/
10.1563/1548-1336%28 2008%2934
%5B107%3AIPOMMD%5D2.0.CO%3B2
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.
CONCLUSIONS
Immediate placement of multiple mini dental implants into fresh extraction sockets can support a medium- span FIXED partial denture.
4: MDI Clinical Studies from Around The USA
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
http://www.joionline.org/doi/pdf/
10.1563/AAID-JOI- D-10-00052.1
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.
FIXED PROSTHETICS
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.
CONCLUSIONS
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 Clinical Studies from Around The USA
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: [email protected]).
Journal of Oral Implantology 34 Vol. XXXII/No. One/2006
http://www.joionline.org/doi/
pdf/10.1563/778.1
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.
Conclusion:
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 Clinical Studies from Around The USA
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 .
Conclusion
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.)
CASE SR
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.
CASE VM
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.
CASE JC
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 al 13 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 Clinical Studies from Around The USA
Willimantic, Connecticut 2016
Case for Smaller Diameter Implants 2016
Dr. Dennis Flannigan
Journal of Oral Implantology : 10.1563/aaid-joi-D-16-00106
http://www.joionline.org/doi/pdf/
10.1563/aaid-joi-D-16-00106
Dear Editor,
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
CONCLUSIONS
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 Clinical Studies from Around The World
Padova, Italy, Beirut and 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.
Abstract
PURPOSE:
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.
RESULTS:
The total implant survival rate was 95.3%. Four implants were lost at second-stage surgery, and 5 more were lost after loading.
DISCUSSION:
SMALL-diameter implants demonstrated a SURVIVAL RATE SIMILAR to those reported in previous studies of STANDARD-size implants.
CONCLUSIONS:
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 Clinical Studies from Around The USA
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 Clinical Studies 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
https://cced.cdeworld.com/courses/99
Abstract
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:
https://cced.cdeworld.com/courses/
99#sthash.6VvFKZP5.dpuf
11: MDI Clinical Studies from Around The USA
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
Abstract:
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
Conclusion
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
INTRODUCTION
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.
CASE REPORT
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.
CLOSING COMMENTS
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 ti
