Recurrence Rate of Proximal Contact Loss Between Implant Restorations and Adjacent Teeth After Proximal Contact Repair: A Retrospective Study

Purpose: Proximal contact loss (PCL) between implant-supported fixed dental prostheses (FDPs) and adjacent teeth has been reported as a common complication of implant therapy. The prevalence of PCL and its potential risk factors have been extensively studied. However, few studies have discussed the recurrent PCL after intervention to restore the proximal contacts. Thus, this retrospective study aimed to evaluate the recurrence rate of PCL and its potential risk factors. Materials and Methods: This study included 41 patients (with 45 implants in the posterior region), who had experienced PCL between implant restorations and adjacent teeth and had received contact repair. Recurrent PCL was recorded and evaluated during routine follow-ups with an interval of 6 to 12 months. The recurrence rates and time were measured. The potential influential factors of PCL were also assessed. Fisher exact test, test, univariate logistic regression analyses, and multivariate logistic regression model were utilized to identify factors influencing PCL. Results: The recurrence rates of mesial PCL were high (> 50%) and the recurrence time became progressively rapid after each repair (5, 3.2, and 2.2 years). Implants with the first PCL recurrence were more likely to be splinted than those implants without recurrence (54.5% vs 18.8%; P =.032). In addition, patients with the first recurrence were slightly older than those without recurrence (55.8 vs 50.1 years; P =.087). Age, implant restoration (splinted vs single), frequent use of interdental brushes, and time to first complaint were the candidate factors associated with recurrent PCL in the univariate logistic regression analysis. The multivariate logistic regression model revealed that only splinted implant restoration was independently associated with a higher risk of recurrence (odds ratio 4.99; 95% confidence interval 1.02–24.31; P =.047). Conclusion: The recurrence rates of mesial PCL were high and associated with the splinted-type design. Also, the recurrence time of PCL accelerated after each repair.