A Comparative Evaluation of the Linear Dimensional Changes of Two Different Commercially Available Heat Cure Acrylic Resins during Three Different Cooling Regimens.

Abstract

Close mucosal adaptation of denture base to the underlying mucosa is of prime importance for denture stability. This however can be affected by various temperature changes which the denture base undergoes during processing and also to its material properties. The aim of the present study was to compare linear dimensional change of heat cure acrylic resin with three different cooling regimens on two different commercially available acrylic denture base resins. Six groups of acrylic specimens with 10 samples each were prepared using either PYRAX or DPI acrylic resin, with a standard processing technique. Three different cooling methods were used for both the commercially available heat cure acrylic denture base resins. Linear dimensional changes were measured between three pre-determined points on the specimens of all the groups using a travelling microscope after removing the sample from the flask. One way ANOVA and unpaired t-test was used for statistical analysis. Linear dimensional change was more in quenching followed by air and water bath method of cooling respectively. Amongst the materials, linear dimensional changes were more in PYRAX than in DPI acrylic. Slow cooling by methods described should be advocated for better mucosal adaptation of the denture base.