5-year clinical experience with BTI® dental implants: risk factors for implant failure

Objectives: The aims of this study were to identify with appropriate statistical tests the risk factors associated with implant failure and to evaluate the long‐term survival of dental implants using implant loss as an outcome variable and performing an implant‐, surgery‐ and patient‐based analysis of failures. Material and Methods: A retrospective cohort study design was used. One thousand sixty patients received 5787 BTI® implants during the years of 2001–2005 in Vitoria, Spain. The potential influence of demographic items, clinical items, surgery‐dependent items and prosthetic variables on implant survival was studied. Implant survival was analysed using a life‐table analysis. Cox proportional hazards regression was used to identify risk factors related to implant failure. Results: Smoking habits, implant position, implant staging (two‐stage implants) and the implementation of special techniques were statistically correlated with lower implant survival rates. Two risk factors associated with implant failure were detected in this study: implant staging (two‐stage implants) and the use of special techniques. Additionally, the overall survival rates of BTI® implants were 99.2%, 96.4% and 96% for the implant‐, surgery‐ and patient‐based analysis, respectively. Totally, 28 out from 5787 implants (0.48%) were lost during the observation period. Most of the patients with implant failure (69.6%) presented chronic or aggressive periodontitis. Conclusions: Implant staging and the use of special techniques are risk factors for implant failure.