The Effect of Multimorbidity on Dental Implant Failure: A Retrospective Cohort Study

SUMMARY Background and Objectives: With an increase in life expectancy on a global scale, there is an increase in the number of patients with multiple systemic conditions and medications. Multimorbidity and polypharmacy may impact health intervention outcomes such as dental implant placement. The purpose of this study was to determine the association of multimorbidity and polypharmacy with dental implant survival and failure rates. Methods: Data was collected from the electronic health record database (Axium) at the University of Illinois at Chicago College of Dentistry. The search identified a random sample of individuals undergoing dental implant placement between March 2005 and March 2022. Survival analysis was performed using the Kaplan Meier estimator, Cox Proportional Hazards models, and RoystonParmar models. Findings: Adjusting for age, gender, and implant location, participants with multimorbidity experienced an almost two-fold increase in the rate of implant loss compared to those without multimorbidity, with a range of plausible values from 1.03 to 3.6 (HR= 1.94, 95% CI [1.03, 3.6], p=0.046). Polypharmacy was not associated with implant loss. Conclusion: Multimorbidity is associated with an increased rate of implant failure. The clinical importance depends upon the concomitant presence of local risk factors, and the baseline rate of implant failure at a particular time. This finding should be interpreted in context of a minimum number of implant failures, a range of plausible values for the HR, the assumption of noninformative censoring, and the potential for unmeasured confounding. It is appropriate to include multimorbidity in risk assessment.