Periotron^® Measurements to Determine Fluoride Retention on Mucosal Oral Surfaces

Method: Initial tests using 0.2 - 1 µl volumes of known fluoride concentrations absorbed in pre-cut filter paper discs were performed to see if Periotron^® measurements affected subsequent F analyses. Samples from 15 subjects were collected in paper discs placed on the tongue, and on the buccal and lower labial mucosa after swallowing, before (baseline) and up to 60 min after a rinse with 0.2% (Flux; Actavis AB, Stockholm) solution. Un-stimulated and stimulated whole saliva (SWS) was collected before rinsing and SWS also 60 min afterwards. After Periotron^®measurement for evaluation of the liquid volume absorbed in the paper discs, the discs and whole saliva samples were kept frozen pending analyses using a F specific electrode.

Result: Periotron^® measurement did not affect the F analysis. F was initially retained to lowest extent on the labial mucosa. Sixty min after the 0.2% NaF rinse, F was increased compared to baseline on the mucosa in the order buccal and labial > tongue, and in SWS. AUC_0-60min on the labial and on the buccal mucosa was significantly and negatively correlated to the labial wetness and stimulated whole saliva secretion rate, respectively, after rinsing with 0.2% NaF.

Conclusion: Periotron^® measurements allowed easy determination of fluoride retained on the oral mucosa. Both mucosal and stimulated whole saliva fluoride concentrations were increased 60 min after a 0.2% NaF rinse compared with baseline. Labial wetness and SWS affected F retention on the lip and buccal mucosa respectively.