Degree of Conversion of Nanoceramic and Microhybrid Composites Activated by Different Polymerization Modes at Different Intervals: An

This is an To determine the DC of two resin composites at different time intervals and modes of polymerization on DC. Two commercially available composite resins-nanoceramic (Ceram X, Dentsply) and microhybrid (Spectrum TPH, Dentsply)-were used in this study. A total of 80 cylindrical samples ( Degree of conversion for the tested composites varied between 44% and 55% for Ceram X and 42% and 45% for Spectrum TPH. A significant difference was observed in DC for Ceram X samples for different polymerization modes (20 seconds and 40 seconds) as well as at 2-7 days measurement, whereas Spectrum TPH did not show any significant difference for polymerization modes. Ceram X demonstrated high DC values compared with that of Spectrum TPH with regard to two different polymerization modes. Lesser the time required for conversion and less the residual monomer left, better is the prognosis of the restoration, and better is the patient satisfaction.