The Potential of a Bioactive, Pre-reacted, Glass-Ionomer Filler Resin Composite to Inhibit the Demineralization of Enamel in Vitro

Abstract

Clinical Relevance A prereacted, glass-ionomer filler fluoride-containing resin composite had lower remineralization potential than glass-ionomer cements but was able to inhibit enamel demineralization; thus, it may be an option for restoring dental surfaces for patients at high risk of caries. SUMMARY Evidence is lacking on the use of surface prereacted glass-ionomer filler resin composites to inhibit demineralization and that simulate real clinical conditions. The present laboratory study evaluated the potential of such composites to prevent demineralization and quantified fluoride (F) and other ions released from restorative materials after a dynamic pH-cycling regimen applied to the tooth material interface in vitro. The pH-cycling regimen was assessed by measuring surface hardness (SH) along with energy dispersive X-ray spectroscopy (EDX). Methods and Materials: Ninety blocks of bovine enamel were subjected to composition analysis with EDX, and were further categorized based on SH. The blocks were randomly divided into 6 treatment groups (n=15 each): F IX (Fuji IX Extra; GC Corporation); IZ (Ion Z, FGM); F II (Fuji II LC, GC Corporation); B II (Beautifil II, Shofu); F250 (Filtek Z250 XT, 3M ESPE); and NT (control, no treatment). The blocks were subjected to a dynamic pH-cycling regimen at 37°C for 7 days concurrently with daily alternations of immersion in demineralizing/remineralizing solutions. EDX was conducted and a final SH was determined at standard distances from the restorative materials (150, 300, and 400 μm). Results: The EDX findings revealed a significant increase in F concentration and a decrease in Ca2+ in the enamel blocks of group B II after the pH-cycling regimen (p<0.05). SH values for groups F IX, IZ, and F II were greater than those for groups B II, F250, and NT at all distances from the materials. Conclusions: The results suggest that each of 3 restorative materials, F IX, IZ, and F II, partially inhibited enamel demineralization under a dynamic pH-cycling regimen.