Investigating factors associated with loss of proximal contact between implant-supported fixed dental prosthesis and adjacent teeth: a systematic review

Abstract

Introduction: Proximal Contact Loss (PCL) is a common complication in patients treated with implants and can affect the success of implant treatments and also lead to food retention and endanger the health of teeth adjacent to implants and caries and periodontal problems in them and Increased mucocytes. Although many studies have been performed on PCL so far, they do not include general and consistent results regarding the extent and factors affecting PCL.This systematic review and meta-analysis aimed to investigate the prevalence of proximal contact loss and associated factors. Methods and Materials: A bibliographic search was conducted in June 2021 with no limitation in the article date or language, and updated in January 2022 by hand searching. There was no time limit on the search to retrieve all studies. The search included randomized controlled trials or quasi-experimental, and in the absence of these studies, cross-sectional or cohort studies were also included. Two authors screened the title and abstract. After evaluating the full text of selected articles, irrelevant studies and or the non-English papers that were impossible to translate were excluded and, in the case of a dispute between the reviewers' selection process, resolved by debate on the eligibility of a study. Standardized critical appraisal instruments from the Joanna Briggs Institute for different types of studies were used to assess the studies’ quality. Comprehensive Meta‐Analysis (CMA) software (version 2.2; Biostat, Englewood, NJ) was used for data analysis. Results: The proximal contact loss (PCL) frequency was 29%. According to the results, the frequency of PCL for the distal side was 7%, and this rate was 21% for the mesial side. The results of the meta-analysis showed that the contact loss event on the mesial side was statistically higher than on the distal side (P<0.0001). There was no statistical difference between other associated factors such as the arch of the mandible or maxilla, retention type, opposing dentition, implant type, molar or non-molar, parafunction behaviors, and vitality of adjacent teeth. there was a significant association between bone loss and PCL, and in individuals with bone loss > 50%, the proximal contact loss was higher (P=0.0006). The PCL of the anterior location was lower than in the posterior location (P=0.004). Although in females the frequency of contact loss was higher than in males, this rate was not statistically significant. Conclusion: The PCL on the mesial side, and the posterior location was high. In individuals with bone loss>50%, the proximal contact loss was higher than in others.