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Fluoride gastrointestinal absorption from Na2FPO3/CaCO3- and NaF/SiO2-based toothpastes
A Falcão1, L M A Tenuta, J A Cury
1Piracicaba Dental School, University of Campinas, Piracicaba, Brazil.
Fluoride bioavailability from toothpaste depends on its solubility, not total concentration. Insoluble fluoride in sodium monofluorophosphate (Na2FPO3) toothpaste reduces absorption, impacting dental fluorosis risk assessment.
Area of Science:
- Dental Research
- Pharmacokinetics
- Toxicology
Background:
- Toothpaste formulations contain varying amounts of soluble and insoluble fluoride.
- Insoluble fluoride may affect fluoride absorption and dental fluorosis risk estimation.
- Understanding fluoride bioavailability is crucial for accurate risk assessment.
Purpose of the Study:
- To investigate the impact of fluoride solubility in toothpaste on bioavailability.
- To compare fluoride absorption from soluble (NaF/SiO2) and insoluble (Na2FPO3/CaCO3) formulations.
- To determine the influence of toothpaste aging on fluoride bioavailability.
Main Methods:
- Two toothpaste formulations with differing fluoride solubility were tested.
- Accelerated aging was used to increase insoluble fluoride content.
- A blind, crossover clinical trial with 20 adult volunteers assessed fluoride bioavailability via saliva and urine analysis.
Main Results:
- Sodium monofluorophosphate (Na2FPO3) toothpaste showed significantly lower fluoride bioavailability compared to NaF/SiO2.
- Aging of Na2FPO3 toothpaste further reduced fluoride bioavailability.
- A strong correlation was found between soluble fluoride ingested and fluoride bioavailability (r = 0.57, p < 0.0001).
Conclusions:
- Fluoride bioavailability from toothpaste is primarily dependent on its soluble fraction.
- Dental fluorosis risk assessment for Na2FPO3-based toothpastes should consider soluble fluoride concentration.
- Toothpaste formulation and aging significantly influence fluoride absorption and potential health risks.
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