HINI

Fluoride: Statements by the C.P.S. and A.A.P.

Editor's note: In this issue, we are reproducing recent statements by the Canadian Paediatric Society and the American Academy of Pediatrics. The A.A.P. statement is currently under review; the interim policy reproduced in this issue was released in May of 1995.

The Use of Fluoride in Infants and Children
A statement by the Nutrition Committee of the Canadian Paediatric Society
Reprinted with the permission of the Canadian Paediatric Society

Comprehensive articles are available that review the mechanisms of fluoride action, the controversy and history of water fluoridation, sources of fluoride and issues surrounding safety and efficacy. ¹These issues will not be reviewed in this document; it updates the previous Canadian Paediatric Society (CPS) statement on fluoride and dental health. ²

CPS statements are meant to apply to all Canadian children unless specific exclusions are highlighted. The statements must recognize the geographic, cultural, ethnic and socioeconomic diversity of infants and children within Canada. An agreement on recommendations for fluoride ingestion has been particularly difficult to achieve because of the diversity in drinking water supply within Canada, the wide variety of sources of fluoride in the diet, the perceived differences in dental hygiene practices within Canada and the lack of comprehensive epidemiologic data with which recommendations should be made. For example, for the many Canadian aboriginal children living in remote communities without a reliable source of running water, routine teeth brushing may not be readily accomplished. Even for children brushing their teeth, varying amounts of toothpaste will be used and some will be swallowed and some spit out. ^3,4Although oral fluoride supplementation has been shown to be efficacious, it is not necessarily a very effective public health intervention. ⁵The question of whether all children not having access to fluoridated water supplies need fluoride supplements is not straightforward, nor is the issue of how the fluoride should be provided. Too much fluoride may result in dental fluorosis, which in its mild form is primarily an aesthetic problem but may damage teeth if severe. ⁶Too little fluoride will increase the risk of dental caries. The challenge is to find a way to provide the right amount of fluoride to all children in a reliable and safe fashion.

We acknowledge that recommendations for fluoride supplementation are controversial and that the current guidelines will not be accepted by all Canadian dentists. The CPS recommendations differ considerably from the current Canadian Dental Association (CDA) guidelines. ⁵

To develop the guidelines, the CPS Nutrition Committee examined literature describing the prevalence and severity of dental fluorosis in Canadian communities, whether their water is fluoridated or unfluoridated. The amount of very mild and mild fluorosis is quite high, both in fluoridated and unfluoridated communities in Canada (15-60%). ⁵The amount of moderate fluorosis is still very low. The data are not complete enough to predict future trends, although very mild and mild forms of dental fluorosis are more prevalent in the 1990s compared with the 1980s.

In 1971, the CPS published its first recommendations for fluoride supplementation. ⁷The initial schedule recommended 0.5 mg/day for infants and toddlers aged 0 to 2 years and 1.0 mg/day for those older than 2 years living in nonfluoridated communities. In 1986, the revised schedule raised the age of fluoride introduction (from birth to the first few months of life) and lowered the recommended dose to 0.25 mg/day up to 2 years of age, 0.5 mg/day for children aged 2 to 3 years, and 1.0 mg/day for those between 3 and 12 years. ²

It is important to note that dental fluorosis, however severe, has not been shown to pose any significant health risks. ⁸Very mild and mild forms of fluorosis is largely benign. ⁹Severe dental fluorosis may result in pitting and brown staining of the teeth. ¹⁰In children, skeletal fluorosis has not been identified as a problem. ¹⁰Chronologically, the window of vulnerability to dental fluorosis involving the permanent anterior teeth lies somewhere between birth and age 6 years. ^11,12Since the current Canadian data on fluorosis are based on examination of the teeth of children who are, for the most part, older than 10 years of age, the effects of the reduced "1986 dosage schedule" on the incidence of fluorosis are currently not available. ⁵It is possible that the trend to increasing incidence of mild fluorosis will have halted, owing to the lower fluoride dose recommendation. ²Continuing surveillance is needed to monitor trends indicative of increasing fluorosis incidence and severity.

In the preceding paragraph, the potential risks associated with early and excessive fluoride use have been summarized. There are many more data showing that fluoride is effective in protecting teeth from caries. ⁸Infants ingesting fluoride (from any source) from an early age have fewer dental caries (including caries of deciduous teeth) than those who do not ingest fluoride at all or than those who start fluoride at a later age. ¹²There is controversy about the degree of protection offered when fluoride is started at different ages. However, if fluoride is not given in the first three years of life, there will likely be a small increase in the prevalence of dental caries in school-aged children living in households with unfluoridated water supplies. ⁵

Sources of fluoride for an infant and young child:

The Nutrition Committee continues to support the principle of widespread water fluoridation. Fluoridated water, however, is a primary source of fluoride for fewer than 50% of Canadians.

Currently, there are many other sources of fluoride for infants and children not living in communities with fluoridated water sources. These include: pharmacologic fluoride drops or tablets; fluoride-containing mouthwashes; fluoride-containing dentifrices; and commercial beverages and foods. With the increasing consumption of fluoride-containing products, there is an increased risk of enamel fluorosis. However, because of the wide variety of products containing fluoride and the variable amounts of fluoride in each product, it is impossible to predict accurately the fluoride intake of any individual. If a large number of fluoride-containing products are ingested by an infant or child, even in a nonfluoridated community, fluorosis may become a problem. ¹³If a small amount of fluoride-containing products are ingested by infants and children, especially in communities where water is not fluoridated, then fluorosis will not be a problem, but an increased number of teeth with caries will be a problem.

The dilemma from a public health perspective is how to develop a single recommendation for a widely scattered population ingesting varying amounts of fluoride-containing products. Does one err on the side of protecting teeth from a potential problem (moderate/severe fluorosis) or on the side of protecting teeth from dental caries?

The answer for part of the population is straightforward. If the community has a fluoridated water supply (>0.6 ppm), then fluoride supplements should not be givenand parents should be warned about the dangers of excessive fluoride ingestion. For those who live in communities (or households) where the water supply is not fluoridated, the Nutrition Committee was faced with two alternative strategies. The first strategy was to recommend oral fluoride supplements (as is currently recommended) as a source of fluoride. The advantage of this choice, if followed, was that a predictable and known amount of fluoride would be ingested by the child from this source. The disadvantages are that not all parents will or can provide the supplement on a regular basis, and that, if taken with other sources of fluoride, too much fluoride may be ingested. The alternative strategy was to recommend that fluoride-containing toothpaste be used to provide the fluoride supplement. The advantage of this choice is that it is a simple and practical way to provide fluoride. The disadvantages are that not all children brush their teeth daily (or twice daily), that not all young children use toothpaste when they brush their teeth, and that, even if toothpaste is used, one cannot predict how much will be spit out versus how much will be swallowed. ⁴If too much is swallowed, then the risk of fluorosis is increased. There are no studies that we are aware of that have compared the effectiveness of fluoride supplements, versus optimal toothpaste use alone, on rates of caries or fluorosis. The Nutrition Committee concluded that the current practice of oral supplementation is more likely to provide a reliable amount of fluoride for infants and children than a recommendation to rely on toothpaste as the primary source of fluoride.

To avoid fluorosis in all children, we continue to recommend that parents supervise teeth brushing in younger children (under age 3) and that only small amounts (pea-size) of fluoride-containing dentifrices be used on a toothbrush. ²In addition, we would encourage manufacturers of toothpastes to lower the concentration of fluoride in toothpastes targeted to young children; to manufacture tubes that make it more difficult to place excessive amounts of toothpaste on a toothbrush; to label fluoride products with the specific fluoride concentration; and to include a warning that children under 6 years of age should use only a pea-sized portion, spit out after brushing, avoid swallowing the paste, and rinse thoroughly afterward.

The Nutrition Committee determined that the potential benefits of carie protection (from the use of fluoride supplements from age 6 months onwards) outweigh the potential benefits of protection from fluorosis (if fluoride supplements were not recommended for young children). The committee recognizes that the likely effectiveness of an oral fluoride supplementation recommendation is limited ¹⁴(i.e., many people cannot or will not provide the supplement on a regular basis) and recommends that monitoring of the effectiveness of the program be carried out. The committee would also like to emphasize that, for fluoride, "more is not better."

From a public health perspective, the Nutrition Committee cannot support the CDA guidelines for fluoride supplementation. The CDA statement requires the practitioner (dentist, doctor, nurse, etc.) to determine whether the individual infant (under age 3 years) is at risk for dental caries before making a recommendation for supplementation. Other than infants with obvious nursing/baby-bottle caries, it is difficult, if not impossible, to identify individual children or groups at high risk for dental caries before age 3. In fact, nearly all children are at some risk and would benefit from fluoride supplements in the absence of fluoridation. The CDA statement does not offer guidance for making this risk assessment, and, even if it did, the committee does not believe that a public health recommendation can be successfully employed if it depends on a prior risk assessment. Finally, the authors of the CDA guidelines state that the adoption of their recommendations might increase caries prevalence among children. ⁵Currently, there is no evidence to show that the CDA recommendations, if followed, will reduce the prevalence of dental fluorosis. Even if the incidence of mild fluorosis were to increase, there are no medical consequences associated with it, and aesthetic consequences for the children and their parents are negligible. ⁹As evidence of the controversial nature of this issue, the CDA guidelines have not been adopted by all provincial dental associations (e.g., Canadian Academy of Pediatric Dentistry, Quebec Order of Dentists, Quebec Association of Pediatric Dentists and the Quebec Association of Community Health Dentists).

Recommendations
The revised supplemental-fluoride dosage schedule is shown in Table 1. This schedule recognizes that alternative sources of fluoride are available in the diet of infants and children living in communities and households that do not have direct access to fluoridated water supplies and that dental fluorosis may be increasing in Canada. Compared with the 1986 CPS fluoride dosage schedule, the age of introduction is later (6 months versus first few months); the initial dose is lower (0.25 mg/day) and continues for a longer period of time (3 versus 2 years); an intermediate dose (0.5 mg/day) is recommended for children 3 to 6 years of age; and the dose for older children is unchanged but continues until an older age (16 versus 12 years). The new dosage schedule is identical to that found in the recommendations recently published by the American Dental Association ¹⁵and the American Dietetic Association. ¹⁶Similar to those found in the previous CPS statement, the general principles for avoiding toxicity while providing an appropriate amount of dietary fluoride are reaffirmed. These principles are outlined in Table 2.

Summary
The new dosage schedule reflects our recognition of the potential impact of increasing fluoride intake on dental fluorosis during this vulnerable age range, yet there is still a need to continue to provide fluoride for carie prevention to populations not exposed to fluoridated water supplies. Although we acknowledge the rationale for the later introduction of fluoride as reflected in the Canadian Dental Association guidelines, we do not believe that there are currently enough data to determine, with accuracy, the effects of changing the recommended age of introduction of fluoride supplements from 6 months to 3 years. Like the CDA, we believe that monitoring trends in dental fluorosis is important. If rates of moderate/severe fluorosis increase, a further modification of the dosage schedule may be necessary.

References

1. Ripa LW. A half-century of community water fluoridation in the United States: review and commentary. J Public Health Dent1993;53(1):17-44.

2. Nutrition Committee, Canadian Paediatric Society. Fluoride supplementation. Contemp Pediatr1987;
(March/April):50-6.

3. Simard PL, Naccache H, Lachapelle D, Brodeur JM. Ingestion of fluoride from dentifrices by children aged 12 to 24 months. Clin Pediatr1991;30(11):614-7.

4. Levy SM. Review of fluoride exposures and ingestion. Community Dent Oral Epidemiol1994;22(3):173-80.

5. Clark DC. Appropriate uses of fluorides for children: guidelines from the Canadian Workshop on the Evaluation of Current Recommendations Concerning Fluorides. Can Med Assoc J1993;149(12):1787-93.

6. Pendrys DG, Katz RV, Morse DE. Risk factors for enamel fluorosis in a fluoridated population. Am J Epidemiol1994;140(5):461-71.

7. Nutrition Committee, Canadian Paediatric Society. Fluoridation or fluoride supplements. CPS statement,
November 1971.

8. Young FE, ed. US Public Health Service: Review of fluoride. Benefits and risks. Washington: US Department of Health and Human Services, 1991.

9. Clark DC. Aesthetic concerns of children and parents in relation to different classifications of the Tooth Surface Index of Fluorosis. Community Dent Oral Epidemiol1993; 21(6): 360-4.

10. Riordan PJ. Perceptions of dental fluorosis. J Dent Res1993;72(9):1268-74.

11. Evans RW, Stamm JW. An epidemiologic estimate of the critical period during which human maxillary central incisors are most susceptible to fluorosis. J Public Health Dent1991;51(4):251-9. (cont'd on page 4)

12. Newbrun E. Current regulations and recommendations concerning water fluoridation, fluoride supplements, and topical fluoride agents. J Dent Res1992;71(5):1255-65.

13. Burt BA. The changing patterns of systemic fluoride intake. J Dent Res1992;71(5):1228-37.

14. Ismail AI. Fluoride supplements: current effectiveness, side effects and recommendations. Community Dent Oral Epidemiol1994;22(3):164-72.

15. American Dental Association Council on Dental Therapeutics. New fluoride schedule adopted. Am Dent Assoc News1994;(16 May 1994):12-14.

16. ADA Reports. Position of the American Dietetic Association: The impact of fluoride on dental health. J Am Diet Assoc1994;94(12):1428-31.

Table 2: Fluoride supplementation guidelines
1. The CPS Nutrition Committee continues to support the principle of universal community water fluoridation.

2. Supplementation is recommended (at the dosage schedule outlined in Table 1) for infants from age 6 months living in homes that do not have access to fluoridated community water supplies.

3. All parents should be warned of the dangers of excessive fluoride ingestion.

4. Manufacturers of fluoride-containing dentifrices targeted to infants and children should be encouraged to:

a) lower the concentration of fluoride in the product;

b) manufacture tubes that make it more difficult to place excessive amounts of dentifrice on a toothbrush;

c) label fluoride products with the specific fluoride concentrations;

d) include a warning that children under 6 years of age should use only a pea-sized portion, should spit out after brushing, should avoid swallowing the paste and should rinse thoroughly afterward.

Table 1: Dosage schedule for dietary fluoride supplements (mg/day)
Fluoride concentration in principal
drinking water source (ppm)

Dosage (mg/day)

Age
6 months - 3 years
3 - 6 years
6 - 16 years
< 0.3
0.25
0.5
1.0
0.3 - 0.6
0
0.25
0.5
> 0.6
0
0
0