Clinical Effects of Interproximal Contact Loss between Teeth and Implant-Supported Prostheses: Systematic Review and Meta-Analysis

Dental rehabilitation with implants is a clinical reality in clinical practice. The Interproximal Contact Loss (ICL) between implant-supported prostheses adjacent to natural teeth is a relatively common occurrence. This systematic review and meta-analysis aims to evaluate the possible clinical effects of the periodontium regarding the ICL between teeth and implanted-supported prostheses. We also identified the main ICL assessment tools described in the literature. This study was registered on the PROSPERO (CRD42023446235), was based on the PICO strategy, and followed the PRISMA guidelines. An electronic search was carried out in the PubMed, B-on, Google Scholar, and Web of Science databases without setting a time limit for publications. Only systematic reviews and comparative clinical trials were included and analyzed. Nineteen publications were eligible for meta-analysis, with thirteen retrospective and six prospective clinical trials. A total of 2047 patients and 7319 prostheses in function were evaluated, and ICL was found in 51% with a confidence interval of 0.40 to 0.61. As ICL assessment tools, dental floss was used in 65%, matrices were used in 30%, and X-ray images were used in 5% of cases. The clinical follow-up ranged from 1 to 21 years, with 50% between 1 and 3 years, 25% between 3 and 10 years, and 25% between 10 and 21 years. ICL was found to occur more frequently in the mandible. No statistically significant difference existed between the anterior (55%) and posterior (47%) oral regions. On the mesial surface, ICL ranged from 13% to 81.4%, possibly due to the different follow-up periods and the diversity of methods used in the assessment. No differences were found for ICL between single or multiple implanted-supported prostheses. Food impaction was the most common effect of ICL and was more prevalent on the implant-supported prosthesis’s mesial surface in the mandible’s posterior region. There was evidence of peri-implant mucositis but without progression to peri-implantitis, and the form of retention or the number of elements was not relevant.