Effect of Thermocycling on Color Stability of Acrylic Resin Materials Immersed in Denture Cleansers

Abstract

Objective: To evaluate the effect of thermocycling on the color stability of heat and self-cure resins after immersion in denture cleansers.

Material and methods: Forty-eight disks of heat and self-cure resins were fabricated. The specimens of each material were divided into 4 subgroups (n = 12) and immersed in different denture cleansers (Distilled water {control}, Corega, StainAway Plus and Polident) daily for 1 week and first color measurements (T1) were recorded (before thermocycing). The specimens were then subjected to 5000 cycles of thermocycling and the second color measurements (T2) were recorded (after thermocycling).

Results: A significant increase of color change was noticed in self-cure compared to heat-cure resins after thermocycling (p=0.001). The color change in heat-cure resins immersed in different solutions was insignificant (p>0.05). Whereas, there was significant color changes in self-cure resins among denture cleansers (p<0.05). The mean difference of color change was greater in self-cure resins immersed in Corega (3.93 ± 2.71) and Polident (3.55 ± 2.06) compared to the control group (0.15 ± 1.66) and lower in specimens immersed in Stain Away Plus (1.36 ± 1.60) compared to Corega. There was a significant decrease in the mean of color change after thermocycling in heat-cure resins immersed in distelled water and Stain Away Plus (p<0.05) and in self-cure resins immersed in Corega, Stain Away Plus and Polident compared to color change before thermocycling (p<0.05).

Conclusion: Aging process resulted in a significant color change in self-cure compared to heat-cure resins and the value of color difference was varied according to the denture cleanser used.