TEMPERATURE AND DIMENSIONAL CHANGES IN THE 2-STAGE PROCESSING TECHNIQUE FOR COMPLETE DENTURES

Objectives: This study concerned the temperature and linear dimensiona l change of heat-cured acrylic resin in the two-stage processing techn ique for complete dentures. Methods: Thermocouples were incorporated i n the acrylic resin for recording temperatures. Measurements between r eference marks were made by a high-resolution digital measuring micros cope. Results: No increase in temperature associated with the exotherm ic nature of the polymerization reaction was recorded. The temperature of the resin followed the waterbath temperature closely. The temperat ures recorded at various regions were in phase with each other. The to tal linear shrinkage of the base after two processing cycles was less than 1% and compares favourably with studies on the single-stage proce ssing technique. Conclusions: Temperature differential is excluded as a reason for the warpage of dentures. The dimensional changes of the d enture base resulting from the two-stage processing technique cannot b e considered to be of any clinical significance.