Some years ago the fluoride content in toothpastes from different Asian countries was measured by using Acidic Phosphatase (AcP) for the measurement of potentially bioavailable fluoride in dentifrices (van Loveren et al. 2005). This way of measurement tries to follow the fact that MFP is hydrolyzed enzymatically in the oral cavity by bacterial phosphatase (Pearce 1983). But so far, no data is available concerning the reproducibility of this method when applied in different laboratories.

The main aim of this study was to assess the reproducibility of fluoride measurements in MFP toothpastes from the Philippines by applying the same protocols and involving three different laboratories. A second aim was to compare the reproducibility of fluoride measurements in NaF toothpastes.