The influence of overhanging proximal restorations on periodontal parameters: a systematic review and meta analysis.

OBJECTIVE: Overhanging proximal restorations are considered a risk indicator for adverse periodontal parameters and could affect the progression of periodontitis. The objective of this systematic review was to determine the association between overhanging proximal restorations in posterior teeth and periodontal parameters. DATA SOURCES: Electronic databases were systematically searched from inception to April 2025; Clarivate Analytics Web of Science, MEDLINE (via PubMed), Embase and Scopus. DATA SELECTION AND EXTRACTION: Potential studies (case-control, cohort, cross-sectional, randomized clinical trials, non-randomized clinical trials) examining proximal restorations in posterior teeth and periodontal parameters were considered for inclusion by two independent reviewers in duplicate. The certainty of evidence was graded using the GRADE approach. Data were pooled using a random-effects model and an Analytic Hierarchy Process (AHP) framework was applied to rank the association of proximal restorations on periodontal health. After removing duplicate results and non-related studies, 54 studies were screened for full-text. Of these, 30 were excluded for different reasons leaving a total of 24 included studies. DATA SYNTHESIS: 24 studies (n = 5955 participants) from multiple countries were included, most with cross-sectional designs. Meta-analysis of eight studies (17,300 teeth/surfaces) showed overhanging proximal restorations were associated with greater radiographic bone loss (mean difference = 0.58 mm; 95% CI: 0.12-1.04 mm), reduced to 0.35 mm after sensitivity analysis. Compared to non-overhanging restorations, overhangs showed significantly greater bone loss (0.82 mm; 95% CI: 0.21-1.43 mm). Three studies (27,679 teeth/surfaces) found increased probing depth (0.28 mm; 95% CI: 0.26-0.30 mm). Risk of bias was high in 42% of studies; the certainty of evidence for bone loss and probing depth was graded low. CONCLUSIONS: Low certainty evidence indicates that overhanging proximal restorations in posterior teeth are associated with increased radiographic bone loss and slight increases in probing depth.