Survival and complication rates of two dental implant systems supporting fixed restorations: 10-year data of a randomized controlled clinical study

Objectives To compare clinical, radiographic, biological and technical long-term outcomes of two types of dental implants over a period of 10 years. Materials and methods Ninety-eight implants were placed in 64 patients , randomly allocated to one of two manufacturers (AST and STM). All implants were loaded with fixed restorations. Outcome measures were assessed at implant insertion (T i ), at baseline examination (T L ), at 1, 3, 5, 8 and 10 (T 10 ) years. Data analysis included survival, bone level changes, complications and clinical measures. Results Re-examination was performed in 43 patients (23 AST and 20 STM) at 10 years. The implant level analysis was based on 37 (AST) and 32 (STM) implants. Survival rates of 100% were obtained for both groups. The median changes of the marginal bone levels between baseline and T 10 (the primary endpoint) amounted to a loss of 0.07 mm for group AST and a gain of 0.37 mm for group STM (intergroup p = 0.008). Technical complications occurred in 27.0% of the implants in group AST and in 15.6% in group STM. The prevalence of peri-implant mucositis was 29.7% (AST) and 50.1% (STM). The prevalence of peri-implantitis amounted to 0% (AST) and 6.3% (STM). Conclusions Irrespective of the implant system used, the survival rates after 10 years were high. Minimal bone level changes were observed, statistically significant but clinically negligible in favor of STM. Technical complications were more frequently encountered in group AST, while group STM had a higher prevalence of peri-implant mucositis.