Effect of Ozone on Adhesion of Bioactive Restorative Materials in Vitro

Objective: This in vitro preliminary study investigated how different ozone formulations affect the adhesion, surface topography, and interfacial ion release of two pediatric bioactive restorative materials. Materials and Methods: Standardized enamel and dentin surfaces (n=96) from extracted human teeth were randomized into 8 groups which differ by the treatment protocol (no treatment, ozone gas, ozonated water, ozonated gel) and restorative material used (Fuji II LC, ACTIVA Bioactive Restorative). Adhesive performance was evaluated after 7 days of storage (HBSS, 37 °C) by shear bond strength (SBS) test and microscopic fracture mode analysis. Surface roughness (Sa) was measured by optical profilometry; interfacial elemental composition was analyzed by Raman spectroscopy and scanning electron microscopy with energy dispersive X-ray detectors (SEM-EDX). Results: Ozone treatment did not significantly affect SBS (mean 3.59±3.23 MPa [min 0.05 MPa; max 11.69 MPa]), fracture modes, or surface roughness (p>0.05 for all domains). Chemical analyses revealed no appreciable difference, with the possible exception of minimal fluoride release. Conclusions: Regardless of the vector agent, ozone treatments showed no significant effect on the short-term adhesion capability of either restorative material, or on the bonding quality with enamel and dentin. Additionally, it seemed that they they neither affected the surface topography nor the possible bioactivity at the interface of the tested materials. However, these preliminary results are restricted to the specific experimental conditions adopted, and further studies are required before any definitive clinical recommendations can be made.