Influence of a thickness and processing method on the linear dimensional change and water sorption of denture base resin.

The purpose of this study was to evaluate the influence of a thickness and processing method on linear dimension change and water sorption in a denture base resin after storage in water for 24 hours, one week, and four weeks. Sixty wax specimens 65 mm long and 10 mm wide were fabricated in three thicknesses, 1.5, 3, and 4.5 mm. Three dimples were made in each wax specimen. A travelling microscope was used to measure the total distance from the uppermost dimple to the lowest dimple to the nearest 0.01 mm. Acrylic resin blocks were polymerized with 2 processing cycles (short and long-cured). Immediately after processing, all samples were measured by the same investigator. They were then weighed by an electronic precision balance capable of measuring to 0.001 g. Data were analyzed by analysis of variance. Thickness and time of storage were statistically significant on the dimensional change (linear and weight changes) of denture-base resin (p < 0.01), showing the influence of the processing method.