Surface Chemical Characterization of Gutta-Percha By FTIR/UATR After Hydrodynamic Ozonated Water Disinfection

Ozonated water has emerged as a promising alternative for the disinfection of gutta-percha cones because of its broad-spectrum antimicrobial activity and the absence of toxic residues. However, information regarding its effects on the chemical structure of gutta-percha remains limited. Therefore, this study aimed to investigate the chemical effects of a hydrodynamic ozonated water system on gutta-percha using Fourier-transform infrared spectroscopy with attenuated total reflectance (FTIR/UATR), determining whether the oxidative modifications induced by ozone were restricted to the material surface or extended into its internal structure. Three experimental conditions were evaluated: untreated gutta-percha, gutta-percha exposed to hydrodynamic ozonated water for 7 min, and ozonated gutta-percha after mechanical removal of a thin superficial layer. FTIR/UATR spectra were acquired in the range of 4000–550 cm⁻¹ using 20 scans, and the spectra were qualitatively compared to identify ozone-induced chemical modifications. The ozonated specimens exhibited broadening of the hydroxyl stretching region (3390–3445 cm⁻¹), changes in the absorption band centered at approximately 1667 cm⁻¹, and reduced intensity of the band near 795 cm⁻¹, indicating superficial oxidation of the polyisoprene matrix. After superficial abrasion, these spectral changes were no longer observed, and the spectral profile became comparable to that of untreated gutta-percha. These findings indicate that the chemical modifications induced by hydrodynamic ozonation are predominantly confined to the outer surface of the material while preserving the chemical integrity of the underlying polymeric matrix. The results support the potential application of hydrodynamic ozonated water as a promising disinfection strategy for gutta-percha, combining effective surface oxidation with preservation of the bulk material structure.