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pH analysis and dental erosive potential of bottled water commercialized in Portugal

Introduction: The knowledge of drinks' pH is essential for the development of preventive strategies in patients at risk of dental erosion [1], since this defines the erosive potential of a drink. The critical pH, below which demineralization is expected to occur is 5.2–5.5 in enamel [2]. Bottled water is often considered innocuous for dental tissues, both by patients and clinicians, and the erosive potential of different brands is neglected, especially in patients with dry mouth symptoms who need a strong water reinforcement [3]. The aim of this study is to demonstrate that bottled waters, commercialized in Portugal, have a minimum erosive potential for enamel, based on the measurement of their pH. Materials and methods: 31 different bottled mineral water, commercialized in Portugal, were analysed by means of the hydrogenionic concentration, by direct potentiometric measurement using a pH electrode calibrated in the range 4.01-10.00. Five independent pH measurements were recorded at 25 °C immediately after opening each bottle, for later calculation of the mean value and standard deviation. Results: From the 31 analysed bottled mineral water, three have shown a mean pH value within or very close to the critical pH range for demineralization (namely bottled waters Dia, Salutis and Vitalis), while the remaining 28 have shown to have mean pH values above. None of the measured waters had a pH mean value below 5.2 (Table 1). Discussion and conclusions: With the results of this preliminary study, we can demonstrate that bottled mineral waters commercialized in Portugal have minimal erosive potential on human dental enamel, based on the pH mean value. Nevertheless, it is essential for the clinician to be aware of the erosive potential of bottled water and educate patients as a preventive strategy. A further investigation concerning this area is needed for wider conclusions.