Bone level changes at implants supporting crowns or fixed partial dentures with or without cantilevers.

OBJECTIVE The aim of this study was to analyze whether or not a cantilever extension on a fixed dental prosthesis (FDP) supported by implants increased the amount of peri-implant bone loss or technical complications compared with reconstructions without cantilevers. MATERIALS AND METHODS Fifty-four partially dentate patients with a total of 54 FDPs supported by 78 implants were enrolled in the study. Twenty-seven FDPs were with cantilever and 27 FDPs were without cantilever (control group). All FDPs were supported by one or two implants and were located in the posterior maxilla or mandible. The primary outcome variable was change in peri-implant marginal bone level from the time of FDP placement to the last follow-up visit. FDPs were under functional loading for a period of 3 up to 12.7 years. Statistical analysis was carried out with Student's t-test. Regression analyses were carried out to evaluate the influence of confounding factors on the peri-implant bone level change. In addition, implant survival rates were calculated and technical complications assessed. RESULTS After a mean observation period of 5.3 years, the mean peri-implant bone loss for the FDPs with cantilevers was 0.23 mm (SD+/-0.63 mm) and 0.09 mm (SD+/-0.43 mm) for FDPs without cantilever. Concerning the bone level change at implants supporting FDPs with or without cantilevers no statistically significant differences were found. The regression analysis revealed that jaw of implant placement had a statistically significant influence on peri-implant bone loss. When the bone loss in the cantilever group and the control group were compared within the maxilla or mandible separately, no statistically significant difference was found. Implant survival rates reached 95.7% for implants supporting cantilever prostheses and 96.9% for implants of the control group. Five FDPs in the cantilever group showed minor technical complications, none were observed in the control group. CONCLUSION Within the limitations of this study it was concluded that cantilever on FDPs did not lead to a higher implant failure rate and did not lead to more bone loss around supporting implants compared with implants supporting conventional FDPs. In contrast to these results more technical complications were observed in the group reconstructed with cantilever.

[1]  Björn Klinge,et al.  A systematic review of the incidence of biological and technical complications in implant dentistry reported in prospective longitudinal studies of at least 5 years. , 2002, Journal of clinical periodontology.

[2]  J. Wennström,et al.  Bone level change at implant-supported fixed partial dentures with and without cantilever extension after 5 years in function. , 2004, Journal of clinical periodontology.

[3]  U. Lekholm,et al.  Oral implant treatment in posterior partially edentulous jaws: a 5-year follow-up report. , 1993, The International journal of oral & maxillofacial implants.

[4]  P J Becker,et al.  Survival of fixed implant-supported prostheses related to cantilever lengths. , 1994, The Journal of prosthetic dentistry.

[5]  O. Miyakawa,et al.  Influence of restoration type on stress distribution in bone around implants: a three-dimensional finite element analysis. , 1998, The International journal of oral & maxillofacial implants.

[6]  N. Lang,et al.  Biological and technical complications and failures with fixed partial dentures (FPD) on implants and teeth after four to five years of function. , 2001, Clinical oral implants research.

[7]  A. Wennerberg,et al.  Implant stability during initiation and resolution of experimental periimplantitis: an experimental study in the dog. , 2005, Clinical implant dentistry and related research.

[8]  G. van der Perre,et al.  Finite element analysis of non-axial versus axial loading of oral implants in the mandible of the dog. , 1998, Journal of oral rehabilitation.

[9]  M. Ogiso,et al.  A histologic comparison of the functional loading capacity of an occluded dense apatite implant and the natural dentition. , 1994, The Journal of prosthetic dentistry.

[10]  N P Lang,et al.  Does excessive occlusal load affect osseointegration? An experimental study in the dog. , 2004, Clinical oral implants research.

[11]  Marco Ghisolfi,et al.  Long-term survival and success of oral implants in the treatment of full and partial arches: a 7-year prospective study with the ITI dental implant system. , 2004, The International journal of oral & maxillofacial implants.

[12]  H. Iplikçioğlu,et al.  Finite element stress analysis of the effect of short implant usage in place of cantilever extensions in mandibular posterior edentulism. , 2002, Journal of oral rehabilitation.

[13]  M. Quirynen,et al.  Histo-pathologic characteristics of peri-implant soft tissues in Brånemark implants with 2 distinct clinical and radiological patterns. , 1991, Clinical oral implants research.

[14]  J. Lindhe,et al.  Bone reactions adjacent to titanium implants subjected to static load. A study in the dog (I). , 2001, Clinical oral implants research.

[15]  D van Steenberghe,et al.  A study of 589 consecutive implants supporting complete fixed prostheses. Part II: Prosthetic aspects. , 1992, The Journal of prosthetic dentistry.

[16]  D van Steenberghe,et al.  Fixture design and overload influence marginal bone loss and fixture success in the Brånemark system. , 1992, Clinical oral implants research.

[17]  G A Niznick,et al.  Bending overload and implant fracture: a retrospective clinical analysis. , 1996, The International journal of oral & maxillofacial implants.

[18]  G E Carlsson,et al.  Bone resorption around fixtures in edentulous patients treated with mandibular fixed tissue-integrated prostheses. , 1988, The Journal of prosthetic dentistry.

[19]  J. Lindhe,et al.  Spontaneous progression of experimentally induced periimplantitis. , 2004, Journal of clinical periodontology.

[20]  A A Caputo,et al.  Effect of cantilever length on stress transfer by implant-supported prostheses. , 1994, The Journal of prosthetic dentistry.

[21]  F. Isidor,et al.  Histological evaluation of peri-implant bone at implants subjected to occlusal overload or plaque accumulation. , 1997, Clinical oral implants research.

[22]  M. Quirynen,et al.  Evaluation of factors influencing the marginal bone stability around implants in the treatment of partial edentulism. , 2001, Clinical implant dentistry and related research.

[23]  G Zarb,et al.  The long-term efficacy of currently used dental implants: a review and proposed criteria of success. , 1986, The International journal of oral & maxillofacial implants.

[24]  Kitetsu Shin,et al.  The influence of controlled occlusal overload on peri-implant tissue. part 4: a histologic study in monkeys. , 1998, The International journal of oral & maxillofacial implants.

[25]  M. Chiapasco,et al.  Implant-supported fixed cantilever prostheses in partially edentulous arches. A seven-year prospective study. , 2003, Clinical oral implants research.

[26]  J. Lindhe,et al.  Histopathological observations of human periimplantitis lesions. , 2004, Journal of clinical periodontology.

[27]  T. Miyata,et al.  The influence of controlled occlusal overload on peri-implant tissue: a histologic study in monkeys. , 1998, The International journal of oral & maxillofacial implants.

[28]  T. Miyata,et al.  The influence of controlled occlusal overload on peri-implant tissue. Part 3: A histologic study in monkeys. , 2000, The International journal of oral & maxillofacial implants.

[29]  S. Aquilino,et al.  Cantilever and implant biomechanics: a review of the literature, Part 2. , 1994, Journal of prosthodontics : official journal of the American College of Prosthodontists.

[30]  C. M. Becker.  Cantilever fixed prostheses utilizing dental implants: a 10-year retrospective analysis. , 2004, Quintessence international.

[31]  A. Sertgöz,et al.  Finite element analysis of the effect of cantilever and implant length on stress distribution in an implant-supported fixed prosthesis. , 1996, The Journal of prosthetic dentistry.

[32]  L. Barbier,et al.  Adaptive bone remodeling around oral implants under axial and nonaxial loading conditions in the dog mandible. , 1997, The International journal of oral & maxillofacial implants.

[33]  R. Kohal,et al.  Changes in peri-implant tissues subjected to orthodontic forces and ligature breakdown in monkeys. , 1998, Journal of periodontology.

[34]  F. Isidor,et al.  Loss of osseointegration caused by occlusal load of oral implants. A clinical and radiographic study in monkeys. , 1996, Clinical oral implants research.