The effect of intracanal ozone application on growth factor release in regenerative endodontics

While conventional irrigation protocols in endodontics provide disinfection, they also influence the release of growth factors from the dentin matrix. Due to its potent antimicrobial, biocompatible, and biostimulatory properties, ozone has recently been introduced in endodontics as an alternative disinfectant in the form of an irrigant solution, intracanal medicament, or gas. Furthermore, its ability to remove the smear layer, open dentinal tubules, and enhance biological activity on dentin surfaces makes ozone an attractive option for regenerative endodontic procedures. However, to the best of our knowledge, no study in the literature has yet investigated the effect of ozone on the release of growth factors from dentin. The aim of this in vitro study was to evaluate the effect of intracanal application of ozone in different forms on the release of growth factors from the dentin matrix. A total of 64 extracted human single-rooted premolar teeth with single canals, removed for periodontal reasons, were used. The samples were randomly assigned into groups and subjected to various irrigation protocols. Following the procedures, samples were incubated, and supernatants collected on days 1 and 7 were analyzed using the ELISA method to measure the levels of TGF-β1 and IGF-1 released. The internal root canal surface area of each specimen was determined by micro-computed tomography (micro-CT), and the obtained values were normalized according to this area and reported as ng/mm². According to the results, TGF-β1 was released in all groups. A statistically significant increase was observed on day 7 compared to day 1 in the standard irrigation protocol group and the ozonated EDTA group, whereas no significant change was detected in the ozonated water group. For IGF-1, growth factor release occurred in all groups, but no statistically significant difference was found between the values at day 1 and day 7. In conclusion, intracanal application of ozone had a limited effect on the release of growth factors from dentin, and its combination with EDTA was shown to enhance TGF-β1 release.