Impact of Acacia arabica Addition on Optical, Mechanical, and Fungicidal Properties of Polymethyl Methacrylate Denture Base Material

Abstract

The aim of the study was to evaluate the optical, mechanical, and microbiological performance of heat-cured polymethyl methacrylate (PMMA) modified by adding various gum Acacia arabica (GA) concentrations.Specimens containing 1, 2.5, 5, 7.5, and 10% GA by weight were prepared, with control specimens containing no GA. Thirty-six rectangular samplings were assessed for color changes, flexural strength, and elastic modulus. Color measurement was conducted using a spectrophotometer. A universal testing machine measured flexural strength through a three-point bending test, and the elastic modulus was calculated. A profilometer and Vickers hardness tester evaluated the surface roughness and hardness. Antifungal activity was assessed by incubating specimens with Candida albicans and counting colony-forming units (CFU/mL).Data were analyzed using the Kruskal-Wallis test for antifungal activity and optical properties and One-way ANOVA for mechanical properties at a significance level of p < 0.05.Groups with higher GA concentrations exhibited significant color changes (p < 0.001). Nonsignificant changes were reported in flexural strength, elastic modulus, or surface hardness (p >0.05), although lower concentrations of GA (1 and 2.5% wt) improved surface hardness. Both 7.5% and 10% wt GA significantly increased surface roughness (p < 0.001). Antifungal activity increased with GA concentration declining from 12 × 10⁸ CFU/mL in the control to no detectable fungal growth in the 10% wt.Low GA concentrations (1 and 2.5%) improved hardness with minimal surface changes, while higher levels (7.5 and 10%) significantly enhanced antifungal efficacy but compromised roughness and aesthetics. A 5% GA concentration offered a balanced compromise, necessitating further investigation.