Fluoride Action Network


AIMS:  The aim of this study is to assess the influence of eating, prior to application of professionally used gels, on the rate of fluoride absorption due to the ingestion of 1.23% acidulated phosphate fluoride (APF).

MATERIALS AND METHODS:  After fasting for 12 hours, 16 adult volunteers (> 65 kg) ingested two types of meal: Breakfast (n = 8) and Lunch (n = 8). Accidental ingestion of fluoride gel used in molding trays was simulated (12,300 ppm; 61.5 mg F; pH = 4.65) 15 minutes after eating. After ingestion of the fluoride solution, 3 mL of venous blood were collected at the following times: Zero (before ingestion) and 15, 30, 45 minutes, 1, 2, and 3 hours. Fluoride concentrations in blood plasma were determined using an ion selective electrode.

RESULTS:  With the exception of time 0 (p > 0.05), the average blood plasma concentration of the breakfast group (BG) (0.34 ± 0.04 mg/L) was higher than that of the lunch group (LG) (0.24 ± 0.03 mg/L), with the moment of peak concentration being 2 hours after ingestion for both groups (BG = 0.4 mg/L; LG = 0.28 mg/L).

CONCLUSION:  Results reinforce the idea that eating before undergoing professional application of fluoride is a factor of extreme importance regarding its safety, and that the time following a patient’s heaviest meal should be the time of choice for planning clinical care.

CLINICAL SIGNIFICANCE:  Our results should be considered when planning collective action that involves the application of the gel on children in a school environment, thus ensuring the procedure’s safety.