Evaluation of the Antimicrobial Effect of Silver Nanoparticles Incorporated Into Heat-Cured Acrylic Denture Base Resin: A Clinical Study

Introduction: Denture-associated candidal stomatitis is one of the most common inflammatory conditions affecting complete denture wearers and is primarily associated with Candida albicans colonization of the denture base. Conventional antifungal therapies are often associated with recurrent infections and patient non-compliance. The incorporation of silver nanoparticles (AgNPs) into polymethyl methacrylate (PMMA) denture base resin has emerged as a promising approach to provide sustained antimicrobial activity and reduce fungal biofilm formation. This study aimed to evaluate the antimicrobial efficacy of an AgNP-incorporated heat-polymerized PMMA denture base resin by assessing changes in Candida colony-forming unit (CFU) counts among completely edentulous patients with denture-associated candidal stomatitis. Materials and methods: A prospective single-group clinical study was conducted on 36 completely edentulous patients diagnosed with denture-associated Candida stomatitis. Complete dentures were fabricated using a heat-polymerized PMMA denture base resin incorporated with AgNP. Microbiological samples were collected from the palatal mucosa before denture insertion (baseline) and one and three months after denture delivery. Candida colony counts were quantified on Sabouraud dextrose agar and expressed as CFU/mL. The data were then analyzed. Repeated-measures analysis of variance followed by Bonferroni-adjusted post hoc tests were performed, with statistical significance set at p < 0.05. Results: All 36 participants completed the study. The mean Candida colony counts decreased significantly from 186.4 ± 42.7 × 103 CFU/mL at baseline to 98.3 ± 28.5 × 103 CFU/mL after one month and 54.6 ± 19.8 × 103 CFU/mL after three months. Repeated-measures ANOVA demonstrated a highly significant reduction in fungal counts over time (F = 187.42, p < 0.001) with a very large effect size (partial η2 = 0.843). Bonferroni-adjusted pairwise comparisons showed significant reductions between all the assessment intervals (p < 0.001). The percentage reduction in Candida colony counts reached 47.3% at one month and 70.7% at three months. Conclusion: The AgNP-incorporated heat-polymerized PMMA denture base resin demonstrated significant and sustained antimicrobial activity by markedly reducing Candida colonization over a three-month period. This biomaterial may serve as an effective adjunct in the prevention and management of denture-associated Candida stomatitis. Further randomized controlled clinical trials with larger sample sizes and longer follow-up periods are recommended to confirm the long-term clinical efficacy and safety.