c da j o u r n a l , vo l 3 6 , n º 4

                                                         f igure 3 b. Panoramic ...

Upcoming SlideShare
Loading in …5

narrow Diameter Implants for mandibular Denture retention


Published on

1 Like
  • Be the first to comment

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

narrow Diameter Implants for mandibular Denture retention

  1. 1. mini-implants c da j o u r n a l , vo l 3 6 , n º 4 r s narrow Diameter Implants for mandibular Denture retention eugene e. labarre, dmd, ms; robert h. ahlstrom, dds, ms; and warden h. noble, dds, ms a bstract  Narrow diameter implants are a lower cost alternative to conventional implants and are used to retain mandibular dentures. The experiences at a dental school predoctoral clinic are reviewed. The cumulative success rate for 626 fixtures placed in a six-year period is 92.6 percent with high patient satisfaction. Narrow diameter implants are a useful adjunct in the long-term management of edentulous patients. I authors eugene e. labarre, dmd, warden h. noble, dds, ms, n 2002, an international symposium solutions to the inaffordability di- ms, is associate professor is clinical professor and at McGill University concluded that a lemma. They are endosseous implants and chairman, Department director, Complex Care Clinic, conventional denture was no longer made of titanium alloy and less than 3 of Removable Prostho- Department of Restorative dontics, University of the the most appropriate option for mm in diameter. They were introduced Dentistry, University of the Pacific Arthur A. Dugoni Pacific Arthur A. Dugoni restoring the edentulous mandible commercially to the dental profes- School of Dentistry, San School of Dentistry, San and that the two-implant retained over- sion in the 1990s and were first used Francisco. Francisco. denture should become the first choice for transitional prosthesis support.3,4 prosthodontic treatment.1 While the Recently, manufacturers have mar- robert h. ahlstrom, dds, ms, is associate professor McGill consensus summarized numerous keted them widely to the profession and and director, Implant randomized controlled trials and longi- patients as lower cost, less invasive, and Clinic, University of the tudinal clinical studies as overwhelming technically easier alternatives to conven- Pacific Arthur A. Dugoni evidence for preferring implant-retained tional implants. They are now used in a School of Dentistry, San dentures, the issues of affordability and variety of applications, including orth- Francisco. access to this level of care were unre- odontic anchorage, single and multiple solved. In the United States, coverage of tooth fixed replacement, bridge repair, dental implants by third parties is in its and removable prosthesis retention.5-10 infancy and is nonexistent in the Med- The small diameter of each fixture (1.8 icaid system. Edentulism in this country mm to 2.4 mm), as well as the reduced is strongly associated with low income, surgical and prosthetic armamentarium, and most edentulous patients cannot result in lower overhead and fees com- afford the high cost of implant dentistry.2 pared with conventional implants. A The use of narrow diameter or patient can receive a mandibular over- mini-implants is potentially one of the denture retained by four narrow diam- a p r i l 2 0 0 8   283
  2. 2. mini-implants c da j o u r n a l , vo l 3 6 , n º 4 f ig ur e 1a. Four sites were marked on ridge f igure 1 b . Four Atlas implants have been placed f i g u r e 1 c. Postoperative panoramic radiograph crest tissue of anterior mandible and pilot osteoto- in the anterior mandible. Note the lack of tissue of 14 mm length Atlas implants. mies will be created through the tissue. The drill trauma. (Atlas Implant, Dentatus USA, New York, N.Y.) is used at slow rotational speed with copious sterile irrigant, to half the length of the proposed implant length if the bone is soft or to the full length of the implant length if the bone is resistant. f ig ur e 2a. Preoperative view of periodon- f igure 2 b . The mandibular canines have f i g u r e 2 c. The patient’s original transi- tally compromised mandibular canines. been extracted and four 15 mm- length MDI tional partial denture was converted to an collared implants (IMTEC Corp., Ardmore, Okla.) immediate complete denture and this was have been placed through the soft tissue at retrofitted over the implants at the conclu- sites No. 21, 23, 26, and 28. sion of the surgery. The patient left the clinic with function and esthetics fully restored. eter implants (figure 1 ) for less than A multiclinic study of 1,029 mini-implants A. Dugoni School of Dentistry has an half the cost of the standard treatment used for mandibular denture reten- edentulous patient base typical of urban with two conventional implants. tion, with service range of five months areas in the United States. Many of Additional benefits of narrow im- to eight years, had an overall success these patients struggle with unstable plants are the ability to place them in rate of 91.2 percent, and 89 percent for mandibular dentures but are unable to horizontally narrow sites (4 mm of fixtures in place for at least five years.14 afford the undergraduate clinic’s basic bone required), minimally invasive Another study reported the long-term two-implant overdenture protocol that surgical technique, and the ability to results for 2,514 mini implants placed in has been in place since 1982 and reliably load the implants immediately. a single office over a five-year period and improves oral function and patient self- A contentious issue with narrow di- subjected to a spectrum of prosthetic confidence. Narrow diameter implants ameter implants is the lack of evidence for anchorage in both jaws: single crowns, are part of the curriculum at Pacific and clinical suitability and success, particularly fixed partial dentures, removable par- have been offered as an alternative and the absence of objective long-term and tial dentures and complete dentures; less costly treatment for our patients prospective comparative studies. It has the overall success rate was 94.2 per- with edentulous mandibles since 2001. been shown that narrow diameter im- cent.15 The encouraging results of both In the last six years, more than 150 plants osseointegrate to the same extent these long-term studies are restrained operators, most of them senior dental as conventional implants, and success by the disclosure statements that the students with close faculty supervi- rates reported for limited patient cohorts lead authors had commercial interests sion, have placed 626 narrow diameter over brief service periods have been favor- in the products cited in the papers. implants, and 37 percent of these were able (93 percent to 98 percent).11-13 The University of the Pacific Arthur inserted at the time of extraction and 2 8 4  a p r i l 2 0 0 8
  3. 3. c da j o u r n a l , vo l 3 6 , n º 4 f igure 3 b. Panoramic radiograph showed lack of bone around implant at site No. 20, with dangerous prox- resulting in extravagant bone loss and imity to the mental foramen (fortunately, the patient had delayed healing. There have been no figure 3a. This patient complained that both remaining implants were painful and loose. Four MDI no paresthesia). The implant at site No. 24 demonstrated paresthesias, as would be expected, significant funneling in the bone. Both implants were collared implants had been placed at a private office removed. because no implants have been placed 12 months previously, and two had been lost already. in the posterior mandible, and all im- Both implants have total exposure of the collar (nor- mally collars are completely embedded in soft tissue). plants were placed at least 5 mm medial to the radiographic mental foramina. immediate denture placement (figure 2 ). surgical/prosthetic treatment. Exclusion The Implant Clinic at Pacific has had Forty-six implants have been lost, due to criteria for patients were conservative: experiences other than treating its own loosening, chronic pain, or infection, for severe or recent cardiac pathology, severe patients. Multiple patients with narrow an overall success rate of 92.6 percent. hypertension, uncontrolled diabetes, or diameter implant problems and failures The protocol of placing four fixtures bleeding disorder, AIDS, any condition who were referred to Pacific from local intraforaminally provided 1 to 3 pounds that seriously compromised bone heal- communities have been evaluated and of resistance to vertical displacement of ing potential or autoimmune response, treated. Common issues included atypi- the denture, and substantially reduced intravenous bisphosphonates, heavy cal implant location, extreme divergence the tendency of the denture to wander smoking, personality disorder or psycho- of implant axes, infection, implant laterally during function. The o-ring sis, substance abuse, and physician veto. rejection, and poor prosthesis fit. retainer (MDI system, IMTEC Corpora- In addition, patients with Class IV Also, the authors have received reports tion, Ardmore, Okla.) or soft liner (Atlas edentulous mandibles (American College from other parts of the United States system, Dentatus USA, Ltd., New York, of Prosthodontists classification, indicating regarding inappropriate treatment with N.Y.) permitted the denture to be entirely less than 11 mm of vertical bone height or these implants (figure 2 ). Egregious fail- supported by soft tissue. If the implants absent clinical ridge) were excluded. Pre- ures have been published.16 Dentists who were placed without raising a soft tissue surgical planning was accomplished with a are accustomed to a disciplined approach flap, patients noted the lack of surgical study model and a panoramic radiograph. to achieve success with conventional im- drama and generally, the healing interval If available, the existing denture plants are dismayed by these instances of was mild. When a conventional denture was used as a general guide for artificial poor planning, execution, and follow-up. was retrofitted to the implants, patient tooth position, location of the bulk of To make matters worse in this field, appreciation of the improvement in den- the denture base and for occlusal plane aggressive marketing strategies feature ture comfort and function was universal. orientation. As a cost control measure, CT patient-targeted infomercials and Web- The word-of-mouth referral of new scans and laboratory fabricated surgical based advertising; dentists are enticed patients by satisfied implant overdenture stents were not used on a routine basis. with promises of enhanced profitabil- patients has been a notable aftereffect of Procedures to retrofit and reline ity; and small diameter implants have this program at Pacific. Another sig- existing dentures were more stringent become the organizational axis for nificant outcome of the narrow diameter than normally encountered in denture profit-dominant denture franchises. overdenture program for students at prosthetics, due to the unforgiving nature This business-first energy obscures the Pacific was the learning and practice of of implant attachments. Post-treatment message that narrow diameter implants distributive justice, which is specifically, swelling, surgical pain, and denture sore can be a useful adjunct to dentistry and in this case, the allocation of implant spots were encountered routinely. Three a benefit to many denture patients. resources and effective procedures among patients had severe local postsurgical The usual high standards of dedica- a diverse edentulous population. swelling that did not respond to anti- tion to scientific inquiry and excellence The experiences at Pacific with narrow biotics, and all fixtures were removed in clinical practice are required of the diameter implants reflected the learning within one month. The worst surgical professional and manufacturing commu- curve associated with the development of complication was a chronic osteomyelitis nities before narrow diameter implants a predictable protocol for a new elective around one narrow diameter implant, will be wholly accepted in dentistry. a p r i l 2 0 0 8   285
  4. 4. mini-implants c da j o u r n a l , vo l 3 6 , n º 4 Conclusions tional implants for partially edentulous patients: a case study. diameter implants with overdentures in severely atrophic Narrow diameter implants have been Pract Proceed Aesthet Dent 13:123-7, March 2001. mandibles. Pract Proced Aesthet Dent 19:168-74, March 2007. 5. Gray J, Smith R, Transitional implants for orthodontic 13. English CE, Bohle GC, Diagnostic, procedural and clinical used successfully to provide retention for anchorage. J Clin Orthod 34:659-66, November 2000. issues with the Sendax mini dental implant. Compend Contin mandibular overdentures. More long-term 6. Vigolo P, Givani A, Clinical evaluation of single-tooth mini-im- Educ Dent 24:3-25, November 2003. studies are needed to compare narrow and plant restorations: a five-year retrospective study. J Prosthet 14. Bulard RA, Vance JB, Multiclinic evaluation using mini dental Dent 84:50-4, 2000. implants for long-term denture stabilization: a preliminary bio- conventional diameter implant outcomes, 7. Christensen GJ, The ‘mini’-implant has arrived. J Am Dent metric evaluation. Compend Contin Educ Dent 26:892-7, 2005. including honest analysis of the problem pat- Assoc 137(3):387-90, March 2006. 15. Shatkin TE, Shatkin S, et al, Mini dental implants for long- terns with narrow diameter variety. 8. Spitler N, Rescuing bridges in trouble. Implant News and term fixed and removable prosthetics: a retrospective analy- Views 4:1-4, November 2002. sis of 2,514 implants placed over a five-year period. Compend r efer e nces 9. el Attar MS, el Shazly D, et al, Study of the effect of using Contin Educ Dent 28:92-100, February 2007. 1. Feine JS, Carlsson G, Implant Overdentures — The Standard mini-transitional implants as temporary abutments in implant 16. Scortecci GM, Bert M, Leclercq P, Implants and Restorative of Care for Edentulous Patients, Chicago: Quintessence overdenture cases. Implant Dent 8:152-8, 1999. Dentistry, London: Martin Dumitz, Ltd., Complications, preven- Publishing Co., 155-7, 2003. 10. Simon H, Use of transitional implants for prosthodontic, tion, correction and maintenance, 432-3, 2001. 2. Eklund SA, Burt BA, Risk factors for total tooth loss in the surgical and orthodontic applications: two-year data. Clin Oral United States; longitudinal analysis of national data. J Public Implants Res 11:49-52, August 2000. Health Dent 54:5-14, 1994. 11. Froum SJ, Simon H, et al, Histologic evaluation of bone- to request a printed copy of this article, please con- 3. Petrungaro PS, Windmiller N, Using transitional implants implant contact of immediately loaded transitional implants tact Eugene E. LaBarre, DMD, MS, University of the Pacific during the healing phase of implant reconstruction. Gen Dent after six to 27 months. J Oral Maxillofac Implants 20:54-60, Arthur A. Dugoni School of Dentistry, 2155 Webster St., San 49:46-51, 2001. January 2005. Francisco, Calif., 94501. 4. Brown M, Tarnow D, Fixed provisionalization with transi- 12. Cho SC, Froum SJ, et al, Immediate loading of narrow 286 a p r i l 2 0 0 8