Determination of fluoride concentration in various brands of toothpaste marketed in Nigeria using ion selective electrode method

The determination of the total fluoride concentration of 13 brands of fluoridated toothpastes marketed in Nigeria was performed using a fluoride ion-selective electrode (ISE). Eleven adult and 2 paediatric toothpastes of different brands were purchased from local markets/supermarkets in Lagos, Nigeria and their fluoride concentrations were determined using an Orion Bench top pH/ISE meter. The fluoride concentrations of the adult toothpastes were found to be between 348.79 [+ or -] 1.0 and 925.78 [+ or -] 1.0ppm, whilst the paediatric toothpastes samples were found to be 349.1 [+ or -] 0.495 and 726.19 [+ or -] 0.5 ppm respectively. The comparison of these results with the permissible values given by the National Agency for Food and Drug Administration and Control (NAFDAC), Standard Organization of Nigeria (SON) and the World Health Organization (WHO), however revealed that none of the paediatric toothpastes fell within the approved range of 425-625ppm. On the other hand, three of the adult toothpastes samples conformed to the recommended fluoride concentration of between 825- 1250ppm. Although fluoride is added to toothpastes and sometimes other products to promote dental health, the ingestion of excess fluoride increases the incidence of fluorosis, which may particularly affect paediatric users. This study has established that the fluoride content of only three out of thirteen toothpaste samples conformed to the SON and NAFDAC standards and therefore provided a rational basis for the quality assessment of various toothpastes. It also highlights the need for stringent regulatory control measures for the determination of fluoride content or concentration in dental products imported into developing countries like Nigeria. Key words: Fluoride, toothpaste, fluoride ion-selective electrode.