Predictors of peri-implant bone loss during long-term maintenance of patients treated with 10-mm implants and single crown restorations

Purpose: The aim of this retrospective study was to evaluate the predictors of peri-implant bone loss in a sample of patients treated with 10-mm implants and single crowns who underwent periodontal/periimplant maintenance (PM) in a Mexican private periodontal practice. Materials and Methods: Outcomes of a group of systemically healthy, partially edentulous patients attended up to July 2012 were assessed. Patient data were considered for inclusion if they involved treatment of partially edentulous sites with 10-mm-long implants and single crown restorations, as well as at least 3 years of regular PM following implant placement. Peri-implant bone loss was evaluated from data recorded at the most recent examination. Logistic regression analysis was performed to investigate associations between peri-implant bone loss and sex, duration of PM, location and number of implants placed per patient, region of the mouth, smoking status, type of implant, and retention of restoration. Results: A sample of 104 subjects who had been treated with four different types of dental implants and maintained for at least 3 years was selected. Of the 148 implants placed and followed for an average period of continuing PM of 6 years (range, 3 to 15 years), only one implant (1.8%) was lost. The outcomes of logistic regression analysis showed that the independent variables smoking, retention of restoration (cemented vs screw-retained), and type of implant (internal-or external-hex) were found to be correlated with peri-implant bone loss, with odds ratios of 39.64, 4.85, and 0.04, respectively. Conclusions: Peri-implant bone loss was significantly associated with smoking status, the type of implant (ie, externally hexed), and type of retention (ie, cemented). Overall, all patients maintained low rates of bone loss.