Influence of the volumes of bis-acryl and poly(methyl methacrylate) resinson their exothermic behavior during polymerization

This study aimed to evaluate the influence of the volumes of a bis-acryl resin (Luxatemp) and a poly(methyl methacrylate) resin (Jet)on their exothermic behaviors during polymerization based on vinyl group conversion. The number of vinyl groups reacted andexotherm were determined based on weight percent of methacrylate groups using FTIR spectroscopy. Temperature changes during polymerization at 23°C were recorded for 20 minutes using a multiple cavity mold overlying a thermocouple. The number of vinylgroups reacted and exotherm of Luxatemp were consistently lower than those of Jet at each resin volume. Mean peak temperature rises of Luxatemp and Jet were in the range of 2.0-6.6°C and 4.2-11.6°C respectively, with Luxatemp and Jet taking 2 and 10minutes respectively to reach their peak temperatures. As their resin volumes increased, their peak temperatures and total peakareas were also observed to increase significantly (p<0.01).