Microhardness Assessment of Different Novel Resin-based Restorative Materials

Objectives: The purpose of this study was to evaluate and compare the microhardness of the silorane-based composite with that of other novel resin-based restorative systems. Methods: 5 types of resin-based restorative materials consisting of hybrid (Spectrum TPH, Dentsply), micro-hybrid (Tetric Ceram, Ivoclar-Vivadent), nano-hybrid (Tetric EvoCeram, Ivoclar-Vivadent), ormocer (Ceram X, Dentsply) and silorane-based (Filtek Silorane, 3M ESPE) composites were selected. Resin-based specimens (n=5) of 5 mm in diameter and 2 mm in thickness were prepared in a polytetraflouroethylene (PTFE) mold. Light curing of the specimens was carried out with a halogen curing light at 800 mW/cm2 for 40 s. Specimens were stored in light proof containers in distilled water at 37 °C for 24 hrs. The Vicker's micro-hardness was measured on top and bottom surfaces by a micro-hardness tester machine. Data were analyzed by one-way ANOVA and Bonferroni post-hoc test. Results: The average microhardness values (mean ± SD) in specimens ranged from 38 ± 4.28 VHN for the hybrid resin composite (Spectrum TPH) up to 95 ± 14.34 VHN for the micro-hybrid resin composite (Tetric Ceram). No statistically significant difference in the microhardness values was found between the resin-based restorative materials tested (P>0.05). Conclusions: From the results, it was concluded that the microhardness of silorane-based composite was comparable with that of other ormocer or methacrylate-based composite materials tested.