A 10-year Retrospective Clinical Study to Identify Risk Indicators for Peri-Implant Bone Loss and Implant Failure

Aim: To evaluate long-term survival and success of dental implants and evaluate indicators affecting the long-term outcome. 

Materials and Methods: Implant survival, success and crestal bone loss (BL) over time were evaluated. For covariates at patient level, Kaplan–Meier estimates of implant survival were compared between groups with the log-rank test. Observed mean bone loss (MBL) was plotted as a function of time. Cumulative frequencies of BL were plotted for different post-op times. Uni- and multivariate analysis was performed. Simple linear mixed and multiple linear mixed models for BL at 1, 5 and 10 years were fitted. 

Results: 407 patients (221 women, 186 men; mean age 64.86 years (range 28–92, SD 10.11)), with 1482 implants, responded. Absolute implant survival was 94.74%; MBL was 0.81 mm (SD 1.58, range 0.00–17.00) after an average follow-up of 10.66 years (range 10–14, SD 0.87). Implant survival was influenced on implant level by smoking, implant width and early bone loss (EBL) > 0.5 mm; on patient level by a history of periodontitis. Indicators influencing MBL after the 1st year were abutment height, type of surgery and implant width, while after 5 and 10 years of function were abutment height, EBL > 0.5 mm and smoking. 

Conclusion: Implant survival was significantly affected by a history of periodontitis on patient level and by smoking, implant width and EBL > 0.5 mm on implant level. Late bone loss was significantly affected by abutment height, EBL > 0.5 mm and smoking. Trial Registration: B670201524796.