Tea Tree Oil Addition on Surface Roughness and Strength of High-Impact Acrylic Resin Material

Objective: Polymethylmethacrylate (PMMA) is porous and rough in nature; this allows food to stick to it and microbes to proliferate, maybe resulting in oral disease. Selecting the right denture cleanser is not enough to prevent all fungi from adhering to the denture or decrease roughness. The essential tea tree oil (TTO) possesses antifungal, antioxidant, and antibacterial characteristics. TTO will be used to study its effect on the surface roughness and impact strength of high-impact acrylic denture material after incorporation with TTO at concentrations of 0%, 6%, and 9% by volume. Materials and Methods: 60 specimens were made and categorized into two groups. Each group consisted of 30 samples and was divided into three different concentrations of TTO (0%, 6%, and 9% by volume). After 48 h incubation in distilled water, all samples were assessed by two tests, the surface roughness test and the impact strength test. Atomic force microscopy (AFM) was used to prove the effect of TTO on the surface morphology at the nanoscale of high-impact acrylic. Results: Tea tree oil had a statistically significant effect on surface roughness, which led to a decrease in surface roughness of high-impact acrylic. Also, TTO has a significant effect on the impact strength of high-impact acrylic at a 9% concentration, which causes a decrease in impact strength (P>0.05), but 6% TTO has a non-significant effect on high-impact acrylic (P<0.05). That means 6% TTO is the better concentration to use to improve the property of acrylic. Conclusion: The high-impact acrylic resin incorporated with the tea tree oil is effective. It appeared that 6% vol TTO will decrease the surface roughness and not significantly affect the impact strength of high-impact acrylic.