Effects of photobiomodulation and bethanechol chloride treatment on salivary composition and flow rate in head and neck cancer patients undergoing radiotherapy: longitudinal interventional experimental clinical study.

Objective: To evaluate the efficacy of photobiomodulation therapy (PBMT) and bethanechol chloride (BC) on the quantity and quality of saliva in patients undergoing radiotherapy (RT) for head and neck cancer.

Methods: Saliva samples were collected from patients before and after RT, who were treated with PBMT or BC. Clinical parameters, including salivary flow rate (SFR), pH, xerostomia, and concentrations of macro and microelements in saliva, were assessed. Data were compared and analyzed using a self-organizing map.

Results: No significant changes were observed in SFR, pH, and xerostomia pre- and post-RT in both the PBMT and BC-treated groups. However, there was an increase in Cr levels in the BC group and a reduction in P levels in the PBMT group.

Conclusion: The results suggest that both PBMT and BC treatments can effectively mitigate the impacts of RT, since quality and quantity of saliva were maintained.