Effect of Ozone on Surface Characteristics of Acrylic Resin

Aim: To study heat-cured acrylic resins' colour, reflection and roughness after being treated by different chair-side Ozone applications. Materials and Methods: 3 samples/test (10*20mm) were cured (Meliodent, Heraeus Kulzer) then conventionally polished (pumice-rag wheel), Highly polished (rotary silicons; Edenta AG, Switzerland) or glazed (Palaseal, Heraeus Kulzer) then stored for 3 weeks. Treatments for 1 or 2 hours in a sealed jar (500mm³, 0.615 L/min); T1: control cycle (dry-air; HealOzone unit, CurOzone USA). T2: Ozone (2,100 ppm; HealOzone unit). T3: Ozone applied within water in the jar(250mm³). One-sample t-test and ANOVA tested surface roughness (µm). 6 blinded examiners viewed control and test samples in terms of color and surface reflection (naked vision or magnification [X2]). Results: No significant surface roughness difference was measured in highly polished or glazed acrylic stored optimally (p>0.05). Conclusion: Poor storage conditions, prior to testing, was the only factor affecting surface reflection but not the color of conventionally polished samples.