Survival rate of implants in a private practice

Objectives: The purpose of this retrospective study was to evaluate the clinical performance and survival rate of implants placed in a private practice. Methods: From April 1997 to December 2004, 314 implants (Ankylos, Friadent GmbH, Germany) were placed in 111 patients (53 male /148 implants, 58 female /166 implants; average age 53 years, ranging from 24 to 79 years). Of these 314 implants, 53,5 % were placed in the mandible, 46,5 % in the maxilla; 19,4 % were placed with simultaneous bone augmentation. After a healing period ranging from three to six month, the osseointegrated implants ( n=304 ) were restored with different prosthetic restorations. Each implant was reassessed on a yearly clinical basis. The statistical survival rate assessment was made using the Kaplan-Meier survival analysis. Results: 10 implants failed during the initial, submerged healing period or at the point of second-stage surgery (maxilla: 1, mandible: 9). One of the remaining 304 implants failed after prosthetic treatment, 6,9 years after insertion. The survival rate according to Kaplan-Meier was 96,9 % after 48 months and 91,8 % after 84 month. The preprosthetic loss rate was 3,2 %, and 0,3 % of implants were lost after prosthetic treatment. For both the upper and the lower jaw, better results were recorded in the posterior part of the jaw than in the intermediate and the anterior part. The age and sex of the patients, the status of jaw (endentulous, partially endentolous), the time of implant placement in relation to tooth extraction and the length and diameter of the implants had no statistically significant influence on the cumulative survival rate. Conclusions: Regarding the calculated survival rate for the implants after a mean observation period of 30 months, the used implant system can be described as a reliable and efficient therapy in a private practice.