Fluoride content of school lunches from an optimally fluoridated and a fluoride-deficient community

Highly acidic pH values of carbonated sweet drinks, fruit juices, mineral waters and unregulated fluoride levels in oral care products and drinks in India: a public health concern

PURPOSE

The objective of this study was to quantify and assess the concentrations of fluoride in commonly used oral care products, fruit juices, bottled waters, soft drinks, favoured bottled milk and milkshakes and to determine the pH of carbonated sweet drinks and drinks marketed in India.

MATERIALS AND METHODS

Various commercial brands of dentifrices, toothpowders, mouthwashes, bottled waters, sweet carbonated drinks and fruit juices were collected randomly from different outlets in Mangalore city, Karnataka, India. A fluoride ion-selective electrode was employed to estimate the fluoride concentrations. A standardised pH meter was used to detect pH in the drinks.

RESULTS

The fluoride level in toothpastes ranged between 96 and 1397 mg/l, whereas in toothpowder the fluoride content ranged from 35 to 1380 mg/l and mouthwash fluoride concentrations varied from 6 to 228 mg/l. The fluoride level in bottled waters ranged between 0.10 and 0.12 mg/l, and that in fruit juices between 0.09 and 0.21 mg/l. Most of the carbonated sweet drinks and fruit juices had highly acidic pH values which ranged between 2.62 and 4.26.

CONCLUSION

Of the wide variety of dentifrices and toothpowders available in India, most brands do not indicate the fluoride levels on their packaging or inserts. Similarly, the unregulated acidic pH values of carbonated sweet drinks are not only potentially contributing to non-carious tooth loss (enamel erosion and dentine erosion), but are also a contributing factor to the weight gain observed in Indian adolescents.

Sources of fluoride intake in children

Wide variations in fluoride intake among children make estimating fluoride intake difficult. This paper discusses the various sources of fluoride intake among children, beginning with a review of the fluoride concentrations of water and other beverages, foods, and therapeutic fluoride products. A review of previous studies' estimates of fluoride intake from diet, dentifrice, fluoride supplements, fluoride mouthrinses, and gels, as well as total fluoride intake also is presented. Then, estimates of fluoride intake among young children of different age groups are summarized, and examples demonstrating the high level of variability of fluoride intake, both from individual sources and in total, are presented. Lastly, this paper discusses the implications of our current level of knowledge of children's fluoride intake, and presents recommendations for the use of fluoride for children in light of this current knowledge. The major recommendations are that: (1) the fluoride content of foods and beverages, particularly infant formulas and water used in their reconstitution, should continue to be monitored closely in an effort to limit excessive fluoride intake; (2) ingestion of fluoride from dentifrice by young children should be controlled, and the use of only small quantities of dentifrice by young children should be emphasized; and (3) dietary fluoride supplements should be considered a targeted preventive regimen only for those children at higher risk for dental caries and with low levels of ingested fluoride from other sources.

Review of fluoride exposures and ingestion

The literature on fluoride intake/ingestion was reviewed critically to determine the current exposure to fluorides for children living in non-fluoridated and fluoridated areas in North America. Fluoride from all sources except mouthrinses and professionally applied topical fluorides was considered, including ingestion from foods and beverages, as well as intake from the use of fluoride dentifrice and dietary fluoride supplements. Data from all of these sources were used to produce estimates of mean daily ingestion. Studies consistently have identified substantial variation in ingestion among individuals. These analyses demonstrated that a substantial proportion of individuals had exposure or ingestion well beyond that of the mean for each source, and often 10-20% received up to several times as much exposure as the mean. Some children probably ingest sufficient fluoride from a single source to exceed the "optimal" fluoride intake recommended from all sources, and are therefore at increased risk of fluorosis. This review highlighted the substantial variation and complexity of fluoride ingestion. Appropriate consideration of these aspects is warranted in efforts to ensure a margin of safety favoring dental caries prevention while limiting objectionable fluorosis.