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

Objective: To determine the effects of disinfection through microwave (MW) and LED disinfection on color stability of Polymethyl Methacrylate (PMMA) and Polyamide (PA) denture base resins. Methodology: A total of 30 specimens of 25x25x5mm dimensions were fabricated in a split mold of stainless steel, which was categorized into 2 groups Polymethyl Methacrylate (PMMA) and Polyamide (PA). These were further differentiated into groups of no exposure (Group A) or microwave (group B) and LED (group C) exposure. Primary color parameters were determined according to CIELab color space for all specimens once immediately after fabrication, using a spectrophotometer within the visible light range of 400 to 700nm. For group B & C, the specimens were exposed to disinfection regimens thrice a week for 4 weeks. After 4 weeks, the specimens were again examined. Data was statistically analyzed using one-way ANOVA and post hoc Tukey’s tests (SPSS ver 26), p <0.05. Results: ANOVA for the PMMA presented no significant results in comparison with PA. On Post Hoc analysis of PA, a significant difference (0.006) was found between groups B and C. Color stability of PMMA remained unaffected statistically after disinfection, but color of PA was adversely affected by MW. Conclusion: The denture base resins’ disinfection regimens did not significantly change color of PMMA. Total color change in PMMA according to NBS remained in the lower range of appreciable color change. For PA, MW disinfection is not feasible as it caused unacceptable color change of the PA base resin.