Properties of fluoride-releasing light-activated resin cement

Fluoroaluminosilicate glass and poly(acrylic acid) in small water phase was incorporated into resin composite cements to reduce or prevent secondary caries around luted restorations. The purpose of this study was to investigate the physical properties and the amounts of fluoride released from four types of visible light-activated resin cements.

A powder was composed of silanized SiO2 filler and 4.5 wt.% (G-4.5), 9.5 wt.% (G-9.5) or 19.5 wt.% (G-19.5) fluoroaluminosilicate glass and 0.5 wt.% reducing agent. The 45.25 wt.% triethylene glycol dimethacrylate (TEGDMA), 45.25 wt.% 2-hydroxyethyl methacrylate (HEMA), 9 wt.% poly(acrylic acid) solution in water and 0.5 wt.% camphorquinone were contained in a liquid. The powder and liquid were mixed at a 3:1 ratio by weight and the three types of specimen disks were cured using a photo-curing lamp. The TEGDMA-based composite cement was used as control (G-0). The specimens were immersed in water at 37 degrees C for 24 h or 6 months and compressive strength (CS) and diametral tensile strength (DTS) were evaluated for the four experimental materials. Disks prepared from the four resin cements were also immersed in deionized distilled water at 37 degrees C, and the fluoride released was measured over a period of 24 weeks.

G-9.5 specimens showed almost the same CS and DTS as G-4.5 and G-0 specimens and significantly higher values for both parameters than G-19.5 specimens after 6 months of water storage. The amount of fluoride released from the three fluoride-containing resin cements continued to increase over the entire experimental period. The fluoride release rates of G-9.5 and G-19.5 resin cements were almost the same and were significantly greater than that of the G-4.5 resin cement.

G-9.5 containing 9.5 wt.% fluoroaluminosilicate glass may be a clinically useful resin cement due to its favorable physical properties and fluoride release.