Physical and microbial adhesion properties of facing crown resins compounded with S-PRG filler

Abstract

Purpose: Discouraging microbial adhesion to dental prosthetics is an effective means of preventing secondary caries and opportunistic infections. We developed prototype resins containing surface reaction-type pre-reacted glass-ionomer (S-PRG) filler for use in facing crowns with the objective of inhibiting microbial adhesion to facing crowns and plaque formation. Methods: In this study, in vivo tests of the antiplaque effect of these resins and in vitro tests of their effect in preventing the adhesion of Streptococcus mutans and Candida albicans were carried out, and the flexural strength, Vickers hardness, and toothbrush wear were also investigated. Results:The flexural strength and Vickers hardness of all the test materials met the ISO criteria. In toothbrush wear tests, increasing the S-PRG filler content made no great difference to the amount of wear. In the antiplaque tests, plaque adhesion was more suppressed as the S-PRG filler content increased. In the microbial adhesion test, increasing the S-PRG filler content made no great difference when the test materials were immersed in distilled water. However, the Streptococcus mutans and Candida albicans counts both decreased when the test materials were immersed in saliva or subjected to thermal cycling. Conclusions: Materials with an S-PRG filler content of 9.4-18.8 wt% had antiplaque properties and excellent physical properties. These results also suggest that they may exert long-lasting antimicrobial adhesion properties.