The Effect of Ozone on Salivary Flow in Patients With Xerostomia and Hyposalivation After Radiotherapy (OZONEXEROSTOMI)

Patients who underwent head and neck radiotherapy and developed xerostomia and/or hyposalivation will be selected. The patients will be randomly assigned into two groups, defined as control and treatment. All patients will complete the xerostomia-related quality of life questionnaires, XeQoLS (Xerostomia Quality of Life Scale) and OHIP (Oral Health Impact Profile). This qualitative assessment will be repeated 1 week after the 6th application and 1 week after the 12th application (T0, T6, and T12). The quantitative assessment will be carried out through the collection of unstimulated and stimulated saliva at the same time points (T0, T6, and T12). Patients will undergo 12 sessions of ozone therapy, once a week, in gaseous form, at a concentration of 10 µg/mL (micrograms per milliliter), applied directly into the major salivary glands. The gas will be administered as follows: * Parotid glands: two distinct points per gland, 1 mL at each point. * Submandibular glands: one point per gland, 1 mL per point at 10 µg/mL. * Sublingual glands: one point per gland, 1 mL per point at 10 µg/mL. The ozone generator equipment will be supplied with medical oxygen (99.5% purity), Dental model, Philozon company. Disposable syringes will be Terumo, 10 mL, and the needle will be BD, 30/13 mm.