Evaluation of a Hydrodynamic Ozonation System for Gutta-Percha Disinfection and Structural Characterization

Gutta-percha (GP), composed of the trans-isomer of polyisoprene, is widely used in endodontic obturation due to its favorable sealing properties. However, it is susceptible to contamination upon exposure to the clinical environment, and its thermoplastic nature precludes thermal sterilization. Conventional disinfection methods using sodium hypochlorite (NaOCl) or chlorhexidine (CHX) require strict control of concentration and exposure time to avoid structural damage. This study evaluated the efficacy of a hydrodynamic system using ozonated water for the inactivation of <i>Enterococcus faecalis</i>. Experimentally contaminated cones were exposed to a continuous flow of ozonated water for 5 and 7 min, followed by microbiological analysis. A seven-minute exposure (57.2 mg/L) resulted in complete bacterial inactivation, enabling further characterization of the biomaterial via FTIR spectroscopy, optical profilometry, scanning electron microscopy (SEM), and tensile strength testing. FTIR revealed subtle changes without compromising the polymeric backbone, while profilometry indicated a significant reduction in surface roughness. Mechanical testing showed preserved tensile strength and a reduction in elastic modulus, suggesting improved anatomical adaptation. SEM analysis did not reveal any relevant morphological alterations. These findings suggest that the hydrodynamic ozonated water system is an effective and safe alternative for disinfecting endodontic materials, with promising clinical applications.