Computer-controlled differential scanning calorimetry of dental composites

Computer-controlled differential scanning calorimetry that has been used to evaluate the heat liberated and the temperature rise associated with the light cure of selected dental composites is described. The effect of postcure heating and the increased ambient temperature of the light cure are examined in terms of a potential secondary cure. The results indicate significant differences between the mean heats of cures of different composites, primarily reflecting the filler fraction variations of the composites. Increased cure activity appears to result from postcure heating as well as thermal activation due to higher ambient temperature of the light cure. The results are analyzed and attributed to variations in resin phase composition and resin content per unit weight of composite as well as to thermally induced enhancement of cure.