Degree of conversion, surface hardness and ion release of a fluoride-releasing resin composite

Dental resin composites are the most commonly used tooth color restorative materials. Despite the satisfactory clinical longivity, currenlty commercially available resin composites are technique-sensitive, lack of biomineralisation mechanism and experience secondary caries. Resin composites with thearaputic ion release inbihiting bacterial growth and the ability of promoting remineralisation are therefore highly desireable. This project aimed to investigate the degree of conversion, surface hardness and ion release of a newly formulated fluoride-releasing resin composite (FRC). A newly formulated fluoride-releasing resin composite FRC and Tetric EvoCeram® Bulk Fill (Tec) were used in the present study. Real time degree of conversion (DC) upto 24h monitored using Fourier Transform Infrared Spectroscopy suggested that FRC can be both self- or light-cured with a DCFRC24 approaching 80% (higher than DCTec24). Post-irradiance hardness measured by a Vickers indenter showed an increase after 24h, but no significant difference* was noticed between groups. Ion release profile (upto 60d) was evaluated using a fluoride ion selective electrode and an inductively coupled plasma–optical emission spectroscopy. Fluoride and calcium release were only found in FRC that increased steadily with immersion time. Technical-insensitive FRC showed better DC, surface hardness compared to a market leading resin composite. FTC also offers sustainable fluoride and calcium release that may promote remineralisation of fluorapatite in an oral environment and inhibit plague bacterial in acid production indicating that the new FRC can be a promising restorative material.*Difference between results was analysed using one-way ANOVA (p<0.05) followed by Tukey`s post hoc test.