Effect of bone density on the survival of 407 sandblasted and acid-etched dental implants: A retrospective multicenter study

BACKGROUND. This study evaluated the success and survival rate of sandblasted and acid-etched dental implants according to the patient’s bone quality. METHODS. A multicenter retrospective study was conducted in five clinical centers between 2016 and March 2019. A total of 407 implants (KONTACT(TM) S, Biotech Dental, France) placed in 229 patients (61.5±12.9 years old) were included. Bone quality, classified as types D1 to D4 (Misch classification), maximal insertion torque, and bone loss were measured. The implant survival rate was evaluated after one year for the overall cohort and for each bone quality. The overall survival rate after four years was also estimated with a Kaplan-Meier analysis. RESULTS. After one year (12.8±9.6 months), eight implants were lost out of 407, representing an overall survival rate of 98%. It ranged from 100% for D1 to 89.7% for D4 (n=39), with significantly higher survival rates for D2 (n=93) and D3 (n=165) (98.9% and 98.2%, respectively) compared to D4. According to the Kaplan-Meier analysis, an overall survival rate of 96.5% was estimated after four years. An average maximal insertion torque of 45±12.6 N.cm and bone loss of 0.2±1.2 mm were measured. CONCLUSION. The high overall survival rate (98%), the average maximal insertion torque (45 N.cm), and the low marginal bone loss indicated good clinical results with acid-etched implants. Despite the relatively high survival rate for each bone quality, the significantly lower results in the D4 group highlight the expected benefits of bone quality-based implants and surgical protocols.