Effect of amorphous and crystalline zirconia on the structural, optical, antifungal and thermal behavior of polymethylmethacrylate/zirconium dioxide nanocomposites in complete denture prosthesis

Polymer-based nanocomposites have gained significant attention nowadays and they have potential to replace the existing materials in different fields including denture stomatitis. Polymethylmethacrylate (PMMA) is one of the promising polymers to meet the demands of current materials research. In the present study, the nanocomposites of PMMA with zirconium dioxide (ZrO₂) nanoparticles were synthesized in amorphous (PAZ) and crystalline (PCZ) forms using a facile chemical approach at 2, 3, 4 and 5 weight percentages. The structural, thermal and optical properties of nanocomposites were studied using AT-FTIR, XRD, SEM/EDX, TGA/DTA, and UV–Vis spectroscopy techniques. PAZ and PCZ both were thermally stable but PAZ was found more stable than PCZ. There was no observation of significant peak on ZrO₂ NPs, among all nanocomposite samples, which indicates complete dispersion of NPs within the solution confirming the formation of PAZ and PCZ nanocomposites. PCZ samples have played a significant role in reduction of colony forming units (CFUs) in 5% concentration. All Candida species gave MIC of 10 µg/mL using fluconazole (control). The MIC of both forms PCZ/PAZ samples was tested at 2, 3, 4 and 5 percentage (w/w) concentrations. The obtained MIC values were ranged between 550 and 995 µg/mL. The PAZ samples have shown high efficacy against all Candida species with MIC of 550, 580, 585 and 590 µg/mL. The PCZ sample of 2% exhibited high MIC values ranging from 990 to 995 µg/mL. However, PCZ sample of 5% gave MIC value of 670–690 µg/mL against all Candida species.

Graphical abstract