► The Fluoride Debate

Durinda J. Mattana, RDH, MS, is an associate professor in the Department of Periodontology and Dental Hygiene at the University of Detroit Mercy School of Dentistry, Detroit.

QUESTION My dentist is involved in a dispute with a local physician about prescribing systemic fluoride to children who drink well water. The children’s physician advised the parent against giving the kids (ages 2 and 5) a fluoride supplement. My dentist and I believe that fluoride helps the developing tooth enamel, which is why systemic fluoride is prescribed. Is this true?

ANSWER First, let’s discuss the issue of pre-eruptive (fluoride ingested during tooth development) and post-eruptive fluoride exposure (topical exposure to the tooth surface). Over the past several years, our understanding of how fluoride works to prevent dental caries has changed. The current understanding is that fluoride’s primary mechanism of action is topical in nature. The key to fluoride’s effectiveness is having it available to the tooth surface when demineralization occurs. Fluoride can then be incorporated into the demineralized enamel surface to become fluorapatite (a less soluble crystal). However, the pre-eruptive benefits of fluoride cannot be ruled out. We know that exposure to fluoride during tooth development affects the morphology of the developing teeth, resulting in teeth with shallower pits and fissures. The best case scenario is to have optimal pre-eruptive fluoride exposure and then continue with post-eruptive fluoride exposure throughout life.

Fluoride supplements in the form of drops, chewable tablets, and lozenges can be an effective alternative to water fluoridation for the prevention of dental caries. Fluoride supplements are intended to compensate for fluoride-deficient drinking water so the clinician must know the fluoride content of the primary source of drinking water and consider other sources of water and fluoride. For those on a private water supply, determining that the water does not contain natural fluoride is crucial. Fluoride supplements also have a topical effect since tablets are chewed and swished before swallowing and lozenges are dissolved in the mouth. For children age 6 months to 16 years who live in a nonfluoridated community, the Dietary Fluoride Supplement Schedule is available (Table 1). Because the use of fluoride supplements during the first 6 years of life in nonfluoridated communities is associated with a significantly increased risk of developing dental fluorosis, some clinicians are hesitant to prescribe supplements. However, dental fluorosis only develops when an excess amount of fluoride is ingested during this period. Therefore, before prescribing dietary fluoride supplements, a thorough fluoride history must be obtained and if supplements are prescribed, the Dietary Fluoride Supplement Schedule must be followed, which is based on the age of the child and the amount of fluoride present in the child’s primary source of drinking water. The amounts in the schedule reflect the additional amount of fluoride intake that is necessary to obtain an optimal anticavity effect and should not be considered the absolute upper limits of fluoride to be ingested each day. The dosage schedule has been lowered two different times in recognition that more sources of fluorides are available today. Parents of young children should also be counseled on the safe use of fluoride products as excess amounts of these products can lead to dental fluorosis.

While the American Dental Association, the American Academy of Pediatrics, and the American Academy of Pediatric Dentistry recommend that children age 6 months to 16 years living in a nonfluoridated community take fluoride supplements, other researchers advocate a delay in supplementation for children at a low caries risk level until the first molars erupt (the time when developing cosmetically objectionable fluorosis on the permanent teeth that are most visible in the mouth is past). In the case of very young children, all possible sources of fluoride must be determined and parents need to be counseled on the proper amount of fluoridated toothpaste to use. Determining whether the child is at a moderate or high caries risk is also important. Research supporting the use of supplements can be found on ADA’s website.¹

Reference
1. Fluoridation Facts. Available at: www.ada.org/public/topics/fluoride/facts/index.asp. Accessed February 9, 2007.