Clinical Thresholds for Repairing Defective Restorations: A Systematic Review of Evidence-Based Decision-Making

This systematic review synthesizes observational evidence on the clinical thresholds used by dental professionals when deciding to repair defective direct restorations. Searches were conducted across major databases and grey literature up to May 2025. Twenty-two studies were included and qualitatively analyzed. The findings indicate that repair decisions are primarily guided by clinical signs such as partial loss or fracture of the restoration, marginal defects, and secondary caries, with decision-making largely based on visual inspection. The review highlights substantial variability and subjectivity in repair thresholds, the absence of standardized decision-making protocols, and a lack of evidence addressing primary dentition. These results underscore the need for clearer, evidence-based guidelines to support minimally invasive restorative dentistry.