Implant failure rate and the prevalence of associated risk factors: a 6-year retrospective observational survey

Introduction: The purpose of this monocentric retrospective observational investigation is to evaluate the implant failure rate observed in an oral surgery department and analyze the risk factors associated with them. Preventative measures will be suggested to reduce the incidence of implant failure. Material and method: All implants removed between 2014 and 2020 were analyzed. The main criterion assessed was the overall failure rate over 6 years of activity;the secondary criteria were the risk factors associated with implant failure. Results: 12 out of 376 implants placed between 2014 and 2019 in 11 patients (mean age: 55.5 ±11.5 years);sex ratio M/F=5/6) were removed, for an overall failure rate of 3.11%. The majority, 83% (10/12) of the lost implants, were in the maxilla, while only 17% (2/12) were placed in the mandible. The main risk factors identified were: a III−IV bone type density (75%, 9/12), pre-implant sinus lift surgery (42%, 5/12) smoking (8.3%, 1/12), surgical site infection (8.3%, 1/12) and rheumatoid arthritis (8.3%, 1/12). Conclusion: The failure rate observed in this oral surgery unit is consistent with the other international studies, confirming the compliance with good clinical practices of the healthcare team. Pre-implant bone surgery is the major risk factor to consider before implant surgery.