Temperature and dimensional changes in the two-stage processing technique for complete dentures.
OBJECTIVE
This study concerned the temperature and linear dimensional change of heat-cured acrylic resin in the two-stage processing technique for complete dentures.


METHODS
Thermocouples were incorporated in the acrylic resin for recording temperatures. Measurements between reference marks were made by a high-resolution digital measuring microscope.


RESULTS
No increase in temperature associated with the exothermic nature of the polymerization reaction was recorded. The temperature of the resin followed the waterbath temperature closely. The temperatures recorded at various regions were in phase with each other. The total linear shrinkage of the base after two processing cycles was less than 1% and compares favourably with studies on the single-stage processing technique.


CONCLUSIONS
Temperature differential is excluded as a reason for the warpage of dentures. The dimensional changes of the denture base resulting from the two-stage processing technique cannot be considered to be of any clinical significance.
Yeung
K C
KC
Prosthetic Dentistry, Prince Philip Dental Hospital, University of Hong Kong.
Chow
T W
TW
Clark
R K
RK
D000180:Acrylic Resins / Q000737:chemistry*; D003080:Cold Temperature; D003735:Dental Casting Technique; D003761:Dental Impression Technique; D003819:Denture Bases; D003824:Denture, Complete; D006358:Hot Temperature; D011108:Polymers / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature; D013821:Thermometers
D000180:Acrylic Resins; D011108:Polymers