Evaluation of the substantivity of a chlorhexidine oral rinse in irradiated head and neck cancer patients.

A trial was conducted to evaluate the substantivity of chlorhexidine in a population of patients who had undergone primary or adjunctive radiation therapy for tumors of the head and neck. Subjects were instructed to first rinse with 0.12% chlorhexidine as per manufacturer instructions, followed by a releasing rinse provided 1 minute, 1 hour, and 4 hours later. All expectorants were collected, pH adjusted, and introduced to the test microorganism. Zones of bacterial inhibition were then measured and recorded. The results suggest that 0.12% chlorhexidine is retained in the oral cavity for at least 4 hours after an initial rinsing and that the property of substantivity remains active in spite of radiation-induced changes in the oral cavity and salivary glands.