Water Sorption and Antimicrobial Performance of Alkali-Treated Moringa oleifera Reinforced Heat-Cured Denture Base Resin: An In-vitro Experimental Study

Abstract: Background: Heat-cured polymethyl methacrylate (PMMA) is susceptible to water sorption and microbial colonization leading to dimensional instability and denture stomatitis. Natural lignocellulose based fillers like Moringa oleifera , may improve the functional and antibacterial properties of PMMA. Objective: To evaluate water sorption and antimicrobial activity of heat-cured Polymethyl Methacrylate resin reinforced with alkali-treated Moringa oleifera powder. Materials and Methods: This in-vitro experimental study was performed at Azra Naheed Dental College and University of Lahore, from 30th March 2025 to 31st December 2025 after obtaining approval from of Ethical Review Board (Ref: ANDC/RAC/2025/66) dated: 29th March 2025. Heat-cured PMMA specimens were prepared as control (0% moringa) and moringa-reinforced groups (5%, 10%, 15% w/w). Powder was washed, oven-dried, milled, sieved, and alkali-treated (5% NaOH), then neutralized and re-dried. Water sorption (%) was measured by mass change after immersion in distilled water for one month. Antimicrobial activity was evaluated using an agar disc diffusion method by measuring zones of inhibition. One-way ANOVA and Tukey HSD were used, followed by Pearson correlation. p-values ≤0.05 were taken as significant. Result: Water sorption decreased with higher moringa content (control 1.82±0.12 to 15% 1.62±0.08; p=0.008). The Antimicrobial zones increased with the increase in concentration (control 0.00±0.00 to 15% 12.17±0.75; p<0.001). In moringa groups, the correlations were very small and non-significant. Conclusion: Alkali-treated moringa reinforcement reduced PMMA water sorption and produced measurable antimicrobial inhibition in a concentration-dependent manner. Keywords: Candida, Denture stomatitis, Moringa oleifera , PMMA denture base, Water sorption.