Fluoride Bioavailability After Ingestion of Water or Foods Prepared With Fluoridated Water

Fluoride Bioavailability in Plasma and Saliva After Ingestion of Water or Foods Prepared With Fluoridated Water

The importance of fluoridated water to control caries is well recognized. Although the mode of action of fluoridated water is known (related to a slight increase in fluoride concentration in saliva/dental biofilm in individuals living in fluoridated areas), the kinetics of fluoride concentration in saliva after ingestion of food prepared with fluoridated water, either from fluoride remaining in the oral cavity after mastication, or from fluoride returning from salivary secretion is not known in details. Therefore, the aim of this study is to assess fluoride bioavailability after ingestion of food prepared with fluoridated water. The study will be in vivo, crossover and double blind, in which 12 adult volunteers will participate. In 4 experimental phases, volunteers will ingest: a. a typical Brazilian meal cooked with non-fluoridated water (<0.1 ppm F); b. a typical Brazilian meal cooked with fluoridated water (1 ppm F); c. non fluoridated water (<0.1 ppm F) and d. fluoridated water (1 ppm F). Immediately before and 5, 10, 15, 30, 45, 60, 120, 180 minutes after the ingestion, a blood sample will be collected by digital puncture, and a sample of unstimulated saliva will be collected. Fluoride concentration in the samples will be determined by an ion specific electrode adapted for microanalysis. Results will be analyzed by ANOVA, with significance limit of 5%.

Ingestion of a typical brazilian meal (rice, beans, meat, french beans, carrots, gelatin and juice) prepared with purified water containing a fluoride dose of 0.8 ug of fluoride/kg body weight (resulting of the natural fluoride concentration in foods).

Ingestion of a typical brazilian meal (rice, beans, meat, french beans, carrots, gelatin and juice) prepared with fluoridated water (1 ug of fluoride/mL), to provide a total intake of approximately 12 ug of fluoride/kg body weight.

Ingestion of purified water with addition of fluoride to provide a total intake of approximately 0.8 ug of fluoride/kg body weight, which represented the same fluoride ingestion dose of the experimental phase with meal prepared with non fluoridated water.

Ingestion of fluoridated water (1 ug F/mL), to provide a total intake of approximately 12 ug of fluoride/kg body weight.

Ingestion of a typical Brazilian meal (rice, beans, meat, french beans, carrots, gelatin and juice) prepared with non-fluoridated water, with sodium fluoride solution added to the juice to provide a total intake of approximately 60 ug of fluoride/kg body weight.

Ingestion of a typical Brazilian meal (rice, beans, meat, french beans, carrots, gelatin and juice) prepared with non-fluoridated water, with sodium fluoride solution added to the juice to provide a total intake of approximately 60 ug of fluoride/kg body weight.

A microsample of blood will be collected by digital puncture before and 5, 10, 15, 30, 45, 60, 120 and 180 min after treatments, to calculate the area under the curve of fluoride concentration in the plasma

A sample of unstimulated saliva will be collected by digital puncture before and 5, 10, 15, 30, 45, 60, 120 and 180 min after treatments, to calculate the area under the curve of fluoride concentration in saliva

Inclusion criteria: Good general health Good oral health Normal salivary flow rate Exclusion criteria: Gastric disorders Renal disorders Systemic diseases Use of drugs that alter salivary flow rate/renal excretion

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