Effect of a Self-Etching Adhesive System Containing a Novel Antimicrobial Polymer (QAMP) on Inhibiting Carious Lesions by Evaluating the Mechanical Properties of the Resin–Dentin Interface

Abstract

The objective of this study was to assess the in vitro effect of a quaternary ammonium methacrylate polymer (QAMP) incorporated into a self-etching adhesive system on inhibiting caries by evaluating the mechanical properties of the adhesive interface. Twenty-four human third molars were distributed into: Clearfil™ SE Bond containing 5% QAMP (experimental group), Clearfil™ Protect Bond (positive control), and Clearfil™ SE Bond (negative control). Teeth of each group were divided according to the method for producing artificial caries lesions: pH-cycling or microbiological assay. All samples were sectioned and polished in order to obtain hardness (H) and Young's modulus (E) values by nanoindentation test in the hybrid layer and dentin. Data were analyzed by ANOVA and Games Howell's post hoc test (α = 0.05). Regarding the hybrid layer, Clearfil™ SE Bond containing QAMP demonstrated H and E values statistically higher than Clearfil™ SE Bond in both pH-cycling and microbiological experiments. Considering dentin, Clearfil™ SE Bond containing QAMP showed H and E values statistically higher than Clearfil™ Protect Bond and Clearfil™ SE Bond in the pH-cycling method and then Clearfil™ SE Bond concerning the microbiological method. In general, Clearfil™ SE Bond containing QAMP provided better mechanical properties for the resin–dentin interface after cariogenic challenges.