Fluoride concentration and pH in bottled waters commercialized in Chile: Implications for oral health

Abstract

An increased consumption of bottled water is overshadowing the traditional intake of tap water. Community water fluoridation is described an effective public measure for delivering fluoride (F) for dental caries prevention. Although community water fluoridation implementation varies regionally, it is desirable that our daily water contains optimal fluoride levels and a safe pH for dental health protection. Here, we determined F concentration and pH of commercially available bottled waters in Chile. Varieties (mineral, purified, and flavored) were obtained in duplicate from different batches. F and pH were measured using a calibrated F-specific ion electrode and pH meter, respectively. From 76 different brands, 100 % have F concentrations below the recommended range (0.6–1.0 ppm F), mineral water showing significantly higher levels (0.15±0.009; p<0.05) than purified (0.09±0.080), and flavored (0.07±0.063). Most brands exhibited levels below the critical pH for both enamel (71.05 %, n=54) and dentine (80.26 %, n=61). A 46.1 % (n=35) had values below pH 4. Flavored waters had significantly lower pH (3.19±0.12; p<0.05), than purified (6.16±2.81) and mineral (pH 6.21±2.59). The analyzed bottled water, regardless of type, lack sufficient F for caries prevention. Their low pH, particularly in flavored options, might be related to an increased risk of erosive tooth wear. Implementing fluoride and pH labeling is desirable to empower consumers to make informed decisions.