Comparing the effectiveness of Transcutaneous Electrical Nerve Stimulation (TENS) and Pilocarpine mouthwash with standard care on salivary flow in patients with radiation-induced xerostomia: a randomized controlled trial

Background: Patient with radiation-induced xerostomia is a well-recognized consequence of radiation therapy, particularly in cases involving head and neck malignancies. This condition, characterized by a persistent and often severe dryness of the mouth, arises due to the detrimental effects of radiation on the salivary ductal system. While ageing is associated with a natural decline in salivary function, radiation-induced xerostomia exacerbates this physiological change, resulting in a substantial reduction in salivary production. Methods: A randomized controlled trial involving 75 patients will be randomly allocated to Group A: TENS therapy, Group B: 2% Pilocarpine mouthwash and Group C: Standard care with 25 in each group. Pre- and post-intervention unstimulated saliva will be collected. Participants’ salivary flow, xerostomia-related quality of life, oral dryness, oral hygiene index-simplified (OHI-S) score, salivary pH and viscosity will be recorded at baseline and 1st, 3rdand 6th-month post-intervention. The Challacombe scale of clinical oral dryness and the Xerostomia-Related Quality of Life Scale (XeQoLS), respectively, will be used to measure the degree of xerostomia and oral health-related quality of life. Appropriate descriptive and inferential statistics will be applied. Statistical significance is set at p≤0.05. Expected outcome: This trial will help determine whether TENS therapy and 2% pilocarpine mouthwash are equally effective at increasing salivary flow and improving the quality of secreted saliva among patients with oral dryness when compared with the use of standard care.