Effectiveness of Ozone Treatment, Ultrasonic Treatment, and Ultraviolet Irradiation in Removing Candida albicans Adhered to Acrylic Resins Fabricated by Different Manufacturing Methods

Abstract

Acrylic resins are commonly used for denture bases due to ease of molding but are prone to water absorption and microbial contamination. This study aimed to evaluate the effects of ozonated water immersion (OZ), ultrasonic cleaning (US), and ultraviolet (UV) irradiation on the removal of Candida albicans from acrylic resins produced by heat curing and additive manufacturing. The resin specimens were then subjected to treatment with OZ, US, UV irradiation, and commercial denture cleansers. Following treatment, the number of viable C. albicans cells was quantified and statistically analyzed (α = 0.05), morphology was observed under a scanning electron microscope (SEM) and fluorescence imaging. OZ, US, and UV irradiation significantly reduced the viable C. albicans count. Notably, the combination of the three treatments achieved a reduction exceeding 99.9% of viable cells. Although SEM revealed that C. albicans remained on the specimens, fluorescence imaging demonstrated a progressive decrease in viable cells and an increase in dead cells with each treatment, with the greatest effect observed when the three treatments were combined. The difference of removal behaviors of C. albicans among fabrication methods was not observed, comparable to denture cleaners. The combined application of all three treatments was the most effective strategy for microbial removal.