Fluoride content of toothpastes available in South Africa

A high dental caries burden coupled with a lack of water or salt fluoridation make it imperative that toothpastes available to the South African consumer demonstrate adequate potential for caries control and contain between 1000ppm and 1500ppm total fluoride (TF), with at least 1000ppm F in free available/soluble form.

The objective was to determine TF, total soluble fluoride (TSF) and insoluble fluoride (IF) concentrations in 22 fluoride toothpastes commercially available in South Africa. Samples were purchased from a major pharmaceutical and food retailer located in the two metropolitan areas in South Africa. TF and TSF concentrations were determined potentiometrically, in quadruplicate, following acid hydrolysis of the samples using a calibrated Combination Fluoride Ion Selective Electrode. IF was calculated by subtracting TSF from TF.

Although TF content was found to be statistically significantly lower than manufacturer declaration (3.2x10-⁷; p≤0.05), 77.3% of the samples still contained adequate free, available/soluble F levels. Relative mean TSF content for toothpastes formulated with a calcium-based abrasive was 85% (sd ±14.5; n=6) as opposed to 98.6% (sd ±2.6; n=16) for those containing silica.

The total fluoride concentration of all the toothpastes was lower than that declared by the manufacturers, with one in four having TSF concentrations of less than 1000ppm F. The relative TSF concentrations for the calcium-containing toothpastes were lower than for the silica-based products, reducing their preventive and protective potential. The results call for strengthened regulation and quality control of fluoride toothpastes in South Africa, as well as international efforts to improve related norms.