Effects of Microwave and Light Emitting Diode as Disinfection Methods on the Dimensional Stability of Polymethyl Methacrylate and Polyamide Denture Base Resin

Objective: To compare the effects of microwave and light emitting diode disinfection on the dimensional stability of two denture base materials; polymethyl methacrylate and polyamide. Study Design: In-vitro study Place and Duration of Study: Peshawar Dental College and Material Research Laboratories, University of Peshawar from 10 June 2021 to 8 December 2021. Materials and Methods: Fifteen specimens each for polymethylmethacrylate and polyamide were divided into three groups, control, microwave & light emitting diode. The specimens for microwave group were irradiated at 1000W for 3 minutes, thrice a week. The specimens for light emitting diode group were disinfected in a device for 30 minutes, thrice a week. The control group specimens were placed in distilled water for 4 weeks. Dimensions were measured before disinfection, and four weeks after the assigned disinfection. The mean and the standard deviation of the differences between three groups were statistically analyzed using one-way ANOVA and after obtaining significant values, through post hoc Tukey HSD. Results: For polymethylmethacrylate highest dimensional difference (-9.02mm) was noted for microwave disinfected group while the control group showed the lowest value (-6.99mm). For polyamide, the highest dimensional changes were recorded for light emitting diode group (8.66mm) and the lowest (-7mm) for the control group. Statistical analysis showed that the differences were significant for both polymethylmethacrylate and polyamide when compared with the control (p<0.05) but insignificant when microwave disinfected group was compared with light emitting diode group (p>0.05) Conclusion: No significant difference in dimensional stability of both the denture base resins was observed after disinfection with microwave and light emitting diode.