Title: 3271 - Enamel Fluoride Uptake From Two KNO3 Containing Toothpastes


Yusuke Hokii (Presenter)
GC America Inc

Clifton Carey, University of Colorado


Objectives: The enamel fluoride uptake (EFU) from toothpaste is thought to be an important quantity that may be reflective of anticaries efficacy. Toothpastes that contain other active ingredients may have altered EFU. We designed an experimental dentifrice called MI Paste ONE to enhance fluoride enamel uptake at the tooth surface. We compared the EFU of this experimental 1100 ppmF toothpaste that contains Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP) and potassium nitrate (5% KNO3 desensitizer) to a commercially available 1100 ppmF toothpaste that also contains 5% KNO3 to investigate the role that CPP-ACP may have on EFU.

Methods: Sixteen caries free human enamel slabs ~4x4mm were polished to 600 grit, baseline F-content determined (15s with HClO4), repolished, demineralized in lactic acid gel for 24 hours then soaked in saliva-like solution (SLS) 24 hours. Two groups (n=8) were exposed to either the experimental or commercial toothpaste slurries (1:3 toothpaste:DI-H2O) for 4 hours daily for 4 days. The samples rinsed in DI-H2O and soaked in fresh SLS for 20 hours each day. On day 5 the samples were extracted 4 times (15s, 1 mol/L HClO4). The extracts were combined for each sample and fluoride concentration determined via F-ISE after a modified Taves diffusion procedure to separate fluoride from the sample matrix. EFU=(measured fluoride extracted less baseline fluoride)/sample area mm2.

Results: The modified Taves diffusion procedure was required because neutralization of the acidic extract for direct F-ISE analyses caused precipitation of potassium and fluoride salts. The experimental dentifrice had significantly greater EFU=0.062±0.015 ppmF/mm2 than the commercial dentifrice EFU=0.035±0.016 ppmF/mm2 (p=0.0016, t-test).

Conclusions: The presence of CPP-ACP enhanced the uptake of fluoride into enamel.

Disclosure Statement:
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: Yusuke Hokii is employed by GC America Inc.