INFLUENCE OF SODIUM HYPOCHLORITE AND EDTA ON THE MICROHARDNESS OF ROOT DENTIN: LITERATURE REVIEW

Abstract

Endodontic irrigation is the process of cleaning and disinfecting the root canal system during endodontic (root canal) treatment to remove debris, bacteria, and the smear layer. This procedure is essential because mechanical instrumentation alone does not completely clean the internal walls of the canal; therefore, irrigation with specific substances is necessary. Sodium hypochlorite, used in different concentrations, has been the solution of choice among professionals because it has antimicrobial action, acts as a tissue solvent, has an alkaline pH, a whitening effect, is deodorizing, and has low surface tension. Ethylenediaminetetraacetic acid (EDTA) acts as a chelating agent to remove the smear layer from the root canal walls. In this sense, the use of irrigating solutions alters the chemical composition of dentin, decreasing its microhardness, which affects the clinical performance of endodontically treated teeth. Both irrigants have a negative impact on dentin, which is directly related to the application time, concentration, and combination of protocols used. Therefore, the objective of this work was to review the literature regarding auxiliary chemical substances such as NaOCl and EDTA and their influence on the reduction of root dentin microhardness.