Effects of mouthguard and paste containing S-PRG filler on remineralization of artificial subsurface carious lesions

Abstract

The aim of this in vitro study was to evaluate the remineralization effects of ethylene-vinyl acetate (EVA) sheet (sample; SHOFU) and paste (PRG Pro-Care Gel®; SHOFU) containing surface pre-reacted glass-ionomer (S-PRG) filler. Extracted human premolars were decalcified to create subsurface carious lesions on the buccal side. Decalcified tooth specimens were then covered by EVA sheets with two different S-PRG filler contents either with application of paste (PRG MG-Paste and EVA MG-Paste groups) or without application of paste (PRG MG and EVA MG groups), then immersed in a remineralization solution. Control group teeth were not covered with any mouthguard and did not receive application of paste. Micro-CT (μCT) images of the teeth before and after the remineralization process were obtained to compare mineral gains. The percentage remineralization (%R) of each group was calculated using the mineral density (MD) profile from μCT. The microstructure of the tooth surface was observed under scanning electron microscopy, and constituent elements were examined using an electron probe micro-analyzer. The PRG MG group showed a significantly higher %R than the Control or EVA MG groups. The PRG MG-Paste group showed a significantly higher %R than the PRG MG group. In the PRG MG-Paste group, small precipitations were observed on tooth surface, and silica and aluminum were detected. The combination use of S-PRG filler containing EVA sheet and PRG Pro-Care Gel exhibits a synergetic effect on remineralization of pre-cavitation carious lesions.