Risk factors for dental implant failure: A 10-year retrospective study

Abstract

Background: Owing to the high long-term survival rates of osseointegrated dental implants it has become increasingly used as the treatment of choice to replace missing teeth in the past few decades. Nevertheless, implant failures and loss may occur as a result of biological and technical complications. Aim: To identify the risk factors associated with early and late implant failures in patients treated at Dubai Health Authority (DHA) and establish risk assessment model.

Materials and Methods: A total of 645 patients aged ≥18 years had 830 failed implants at DHA between 2010 and 2019. The data was manually collected from records available at DHA and then analyzed using logistic regression analysis. The collected data was divided into two sub-categories; systemic-/patient-related factors, and implant-/site-related factors. The strength of association between the frequency of early and late implant failure and each variable was measured by chi-square analysis. Differences were considered statistically significant at P < 0.05. For systemic and patient-related factors, the patient was considered the unit of analysis. For implant-related factors, the implant was considered as the statistical unit.

Results: Out of 14191 implants inserted during the observation period, 721 implants failed before loading (5.1%) and 109 implants failed after loading (0.8%). More than half of late failed implants (59.3%) were single implant and (57.0%) were screw-retained prostheses. A significant association was observed between implant failure and histories of treated ii periodontitis (P < 0.0001), previous implant failure (P < 0.0001), and irregular dental attendance (P = 0.006). Implants inserted in the posterior region in both arches had a significant impact on implant failure with more early and late implant failures (P < 0.0001). The other variables did not influence early or late implant failures.

Conclusion: Within the limitations of this retrospective study, the analysis identified plausible risk factors for early implant failure, namely history of treated periodontitis, previous implant failure and irregular dental attendance that would allow clinicians to identify those at risk and ensure continuous peri-implant supportive care. Further studies are necessary to achieve more robust understanding on potential risk factors for implant failures and to provide effective preventive and therapeutic protocols.