Surgical factors related to dental implant failure: A cross-sectional multicentre study on 1,308 dental implants

Implant failure is equivalent to the loss of the implant, which entails biological and economic costs and reduces patient's trust in healthcare professionals. The objective of this study was to estimate the cumulative failure rate of 1,308 implants and identify patient-related and surgical factors associated with implant failure.

Data for this retrospective multicentre study were extracted from six private clinics between June 2006 and December 2022. Patient-related factors, surgical techniques, and implant-related variables were evaluated. Multivariate mixed Cox proportional hazards models and Lasso regularisation were employed to identify predictors of implant failure.

A total of 1,308 implants (510 patients) were inserted, with a failure rate of 2.4% over a mean follow-up period of 38.31±32.54 months. The selected mixed Cox regression models showed that three variables were independently associated with implant failure: Postoperative implant infection (Hazard Ratio [HR]=6.6 [95% CI: 1.8-23.9]; p=0.004), previous implant failure (HR=8.3 [95% CI: 2.6-26.6]; p<0.001), and heavy smoking (>20 cigarettes per day) (HR=99.3 [95% CI: 30.7-321.3]; p<0.001).

With the limitations of the present study, the cumulative implant failure rate was low (2.4%). Nevertheless, strict control of smoking habits and infection risk factors is essential, since implant replacement after failure constitutes and independent risk factor for subsequent failure.