The Effect of Al2O3 Addition on the Thermal Diffusivity of Heat Activated Acrylic Resin

This study aimed at investigating the effect of adding 5% to 20% by weight aluminium oxide powder (Al2O3) on thermal diffusivity of heat-polymerized acrylic resin.

Twenty five cylindrical test specimens with an embedded thermocouple were used to determine thermal diffusivity over a physiologic temperature range (0 to 70°C). The specimens were divided into five groups (5 specimens/group) which were coded A to E. Group A was the control group (unmodified acrylic resin specimens). The specimens of the remaining four groups were reinforced with 5%, 10%, 15%, and 20% Al2O3 by weight. RESULTS were analysed by using one-way analysis of variance (ANOVA).

Test specimens which belonged to Group E showed the highest mean thermal diffusivity value of 10.7mm(2)/sec, followed by D (9.09mm(2)/sec), C (8.49mm(2)/sec), B(8.28mm(2)/sec) and A(6.48mm(2)/sec) groups respectively. Thermal diffusivities of the reinforced acrylic resins were found to be significantly higher than that of the unmodified acrylic resin. Thermal diffusivity was found to increase in proportion to the weight percentage of alumina filler.

Al2O3 fillers have potential to provide increased thermal diffusivity. Increasing the heat transfer characteristics of the acrylic resin base material could lead to more patient satisfaction.