Influence of glycolic acid as a chelating agent for smear layer removal and its effect on the microhardness of root canal dentin - A systematic review.

This study aimed to evaluate the effect of glycolic acid (GA) as a chelating agent on the removal of smear layers and the microhardness of root dentin. This review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, and study quality was assessed using a modified Joanna Briggs Institute (JBI) tool. Two authors independently conducted an electronic search across four databases, supplemented by examining the reference lists of the included articles. A total of five in-vitro studies having variable concentrations (5%, 10%, and 17%) of GA were chosen for this review. Two articles include microhardness and smear layer removal together, two deal with microhardness, and one deals with smear layer removal. The included studies revealed a low overall risk of bias owing to the variability among the studies; the analysis was limited to qualitative assessment, with no meta-analysis performed. Based on the findings, various concentrations of GA (5%, 10%, and 17%) can be considered alternatives for smear layer removal with less impact on root dentin microhardness. However, further studies with proper standardization are required to confirm the effects on root dentin.