Evaluation of the Effect of Ozone Gas and Nanohydroxyapatite Gel Application on Remineralization of Initial Enamel Caries: An In Vitro Study

The aim of this study was to evaluate the effect of several remineralization agents on artificial enamel lesions. Sixty orthodontically extracted, caries-free teeth were embedded in acrylic blocks, exposing the buccal surfaces and these surfaces were standardized with SiCi sandpaper (800,1000,1200 grit). Initial laser fluorescence and microhardness values from the samples were measured and recorded. The samples were exposed to a demineralization solution for 72 h to create artificial caries. The teeth were divided into six remineralization groups: Ozone, nano-HAP gel, Ozone + nano-HAP gel, Nano-HAP gel + Ozone, Fluoride varnish, and a negative control group, followed by a 7-day pH cycling process (18-h remineralization, 6-h demineralization in a day). After pH cycling, microhardness and laser fluorescence measurements were repeated. Following that; a post-treatment cycle was performed 7 days to assess the long-term effects of remineralization treatments. According to the obtained data, the initial microhardness values showed no significant differences between groups (p > 0.05). Statistical analysis revealing a significant difference between demineralization and remineralization processes (p < 0.05) and the most significant microhardness increase was seen in the nano-HAP gel + Ozone group (p > 0.05). Laser fluorescence measurements showed that lesion size decreased in all groups. However, after the post-treatment cycle, the nano-HAP gel + Ozone group was found to have the lowest microhardness (p > 0.05), indicating that although this combination provided the best reminera lization, its effect was not permanent over time.