EFFECTS OF COMPLIANCE WITH FLUORIDE GEL APPLICATION ON CARIES AND CARIES RISK IN PATIENTS AFTER RADIATION-THERAPY FOR HEAD AND NECK-CANCER

The use of fluoride gel applied in a custom tray once daily, has becom e standard for patients who have xerostomia after undergoing radiation therapy. Compliance may be poor as a result of the inconvenient metho d of application and because many patients with head and neck cancer h ave poor health behaviors. Our aim was to investigate the effect of co mpliance with fluoride gel application on caries and caries risk. Pati ents were prescribed neutral sodium fluoride gel (5000 ppm) before und ergoing radiotherapy. Fifty-two patients were willing to visit the den tal clinic for dental examination, measurement or saliva, and quantita tive culture of Streptococcus mutans and lactobacillus species. Before radiotherapy was performed, decayed, missing, and filled surfaces dat a were recorded for all patients in the study. Of these patients, 27 u sed fluoride gel once daily, as directed. Radiation dose, number of fr actions, and duration of radiation had a significant inverse effect on postradiotherapy whole resting saliva (p = 0.04, p = 0.01, and p = 0. 01) and on whole stimulated saliva (p = 0.02, p < 0.01, and p < 0.01). Patients with a subjective feeling of dry mouth had significantly les s saliva production at rest (p = 0.01) and on stimulation (p = 0.01). A trend toward reduction of S. mutans counts was seen in those patient s who used their fluoride gel regularly (p = 0.057). High lactobacilli counts were found in the patients with high and low compliance with f luoride gel use. Differences in the mean caries incidence between thos e who reported compliance with daily fluoride application and those wh o did not comply were not found significant because of the large SD in the patient groups, although differences in the mean for these groups were seen. The lack of a statistically significant difference may be due to the multiple factors associated with caries. Therefore patient care must be individualized, and patients must be assessed at regular intervals to determine the caries risk and caries activity to provide guidance for maintenance of the dentition.