Inhibitory effect of zirconium oxide nanoparticles on adhesion to repaired polymethyl methacrylate denture bases and interim removable prostheses: a new approach for denture stomatitis prevention.

BACKGROUND

Despite drawbacks, cold-cured acrylic resin is still the most common material used in denture repair. Zirconia nanoparticles were among the reinforcements added to increase the strength of the resin. The effect on due to the addition of zirconia nanoparticles to the resin has not been investigated.

PURPOSE

The aim of this study was to evaluate the effect of zirconia nanoparticles added to cold-cured acrylic resin on adhesion.

MATERIALS AND METHODS

A total of 120 acrylic resin specimens with dimensions measuring 22×10×2.5 mm were prepared and divided into two equal groups. One group (repair) comprised heat-polymerized specimens that were sectioned at the center and prepared to create a 2 mm repair area that was repaired with cold-cured resin reinforced with 0% wt, 2.5% wt, 5% wt, and 7.5% wt zirconia nanoparticles. The second group contained intact cold-cured acrylic resin specimens reinforced with 0% wt, 2.5% wt, 5% wt, and 7.5% wt zirconia nanoparticles. Specimens were incubated at 37°C in artificial saliva containing , and the effect of zirconia nanoparticles on was assessed using two methods: 1) a slide count method and 2) a direct culture test. Variations in the number of living were observed in relation to the different concentrations of zirconia nanoparticles. Analysis of variance (ANOVA) and post hoc Tukey's tests were performed for data analysis. If the -value was ≤0.05, then the difference was considered as statistically significant.

RESULTS

It was found that adhesion to repaired specimens was significantly decreased by the addition of zirconia nanoparticles (<0.00001) in comparison with the control group. Intact cold-cured groups and groups repaired with cold-cured resin reinforced with 7.5% wt zirconia nanoparticles showed the lowest count. Tukey's test showed a significant difference between the repaired group and the intact cold-cured group, while the later demonstrated a lower count.

CONCLUSION

The addition of zirconia nanoparticles to cold-cured acrylic resin is an effective method for reducing adhesion to repaired polymethyl methacrylate (PMMA) denture bases and cold-cured removable prosthesis.

CLINICAL SIGNIFICANCE

Based on the results of the current study, zirconia nanoparticles have an antifungal effect, which could be incorporated in the repair material for repairing denture bases and in PMMA removable prostheses as a possible approach for denture stomatitis prevention.