Effect of simulated microwave disinfection on the mechanical properties of three different types of denture base resins.

STATEMENT OF PROBLEM Disinfection of prostheses with chemical solutions has deleterious effects on dentures. The appropriate power setting of microwave for disinfection, without affecting denture base properties, is a controversy. PURPOSE To evaluate and compare the effect of simulated microwave disinfection at a recommended power setting on the mechanical properties of three denture base heat polymerized acrylic resins. MATERIAL AND METHODS Ninety rectangular specimens of each acrylic resin of 65mm × 10mm × 3 mm dimensions were divided into three groups. Group A (Trevalon), Group B (Trevalon- HI), Group C (Ivocap). In each group, thirty specimens were divided into three subgroups with ten specimens in each and they were submitted to MicroVickers hardness, flexural strength, and impact strength tests. In each subgroup, five specimens were tested before the simulated microwave disinfection and they served as the control group. The remaining five were tested after simulated microwave disinfection and they were considered as the experimental group. Simulated microwave disinfection was done in a domestic microwave oven at 650 W for 5 minutes. RESULTS The data were analyzed using One-way ANOVA and t-test. The mechanical properties of the three denture base resins were not altered after simulated microwave disinfection, as compared to those of the controls. CONCLUSION Microwave irradiation at 650 W for 5 min did not affect the mechanical properties of the three denture base resins. Domestic microwave oven, at the prescribed setting, can be used as an alternative method of disinfection for complete dentures without affecting their properties.