Implant prosthodontic management of partially edentulous patients missing posterior teeth: the Toronto experience

STATEMENT OF THE PROBLEM: The clinical success of implant-supported fixed partial dentures has been documented. However, few studies have reported long-term results or any association between implant outcomes and host determinants. PURPOSE: This study reports on implant and prosthesis outcomes in a group of partially edentulous patients treated with Br?nemark implants in the posterior zones. It also examines factors described in the medical history that may influence implant survival. MATERIAL AND METHODS: The charts of patients treated with implants from 1983 and followed prospectively through December 2001 at the University of Toronto were reviewed. One hundred thirty partially edentulous patients treated with implant-supported restorations in the posterior zones (area distal to mental foramen) were selected. Implant and prosthesis treatment outcomes were recorded and analyzed through the Kaplan-Meier and Cox regression methods (P<.05). RESULTS: A total of 130 patients received 432 Br?nemark dental implants in 174 posterior edentulous spans. The mean age of the patients at the time of insertion of the implants was 50.97 +/- 13.27 years. At 15 years, the overall implant and prosthesis survival rates were 91.6% and 89%, respectively. At 5 years, the survival rate of the wide-platform 5-mm-diameter implants was 76.3%. Implant diameter (P=.0001) and a history of a chronic medical condition (P=.01) were correlated with implant survival outcomes. CONCLUSIONS: High success of implant-supported prostheses in the posterior zones of both the maxilla and mandible. It corroborated other studies that have shown higher failure rates for wide-platform implants, emphasizing the need for proper establishment of clinical trials prior to marketing of new implant designs.