by Bonnie C. Dyck, RDH, MPH

From the Past Toward the Year 2000

Community water fluoridation is the deliberate upward adjustment of the natural trace element fluoride to promote public health through the prevention of dental caries (tooth decay) in accordance with scientific and dental guidelines. Fluoride is present naturally in variable amounts in all soils and existing water supplies. It is also present in animal and plant food consumed by people. The highest concentrations in mammals are found in the bones and teeth.

History

• The study of the correlation between fluorides in water and dental health dates back to the early 1900's, when a young dentist, Frederick S. McKay, established a dental practice in Colorado Springs, Colorado. In 1908, Dr. McKay initiated a study to investigate the cause of a developmental enamel defect which he called "Colorado Brown Stain." We know this defect today as dental fluorosis (mottled enamel), or chronic endemic enamel fluorosis. In the late 1920's Dr. McKay made another major discovery, namely, that teeth with mottled enamel were essentially free of dental caries. In 1931, fluoride was identified as the element in drinking water that not only caused mottled enamel but also inhibited dental caries. During the 1930's, Dr. H. Trendly, Dean of the U.S. Public Health Service, and Dr. McKay corroborated to determine if fluoride could be added to the drinking water to prevent cavities. Dr. Dean and his associates conducted several classic studies to establish a community fluorosis index. This research led to further studies that predicted the cause-and-effect relationship between fluoridation and the reduction of dental caries and that also determined what the optimal levels of fluoride should be in a community's drinking water (1ppm).

Four Classic Studies

• Although the studies on fluorides were interrupted by World War II, on January 25, 1945, Grand Rapids, Michigan, became the first city in the world to adjust its water fluoride concentration to a level expected to reduce dental caries and achieve dental health. Four and a half months later Newburgh, New York, added sodium fluoride to its water supply; and in late June, 1945, fluoride was added to the water supply of Brantford, Ontario. In February, 1947, Evanston, Illinois, was fluoridated. These studies firmly established fluoridation as a practical and effective public health measure that would prevent dental caries.

Engineering Aspects

• Although it had been determined that fluoridation was safe and effective, the engineering aspects needed to be developed before community water fluoridation could be more widely implemented. In the 1950's and 1960's, two more individuals emerged on the fluoridation scene, both with the U.S. Public Health Service, Franz J. Maier, a sanitary engineer, and Ervin Bellack, a chemist, helped determine for water fluoridation which fluoride chemicals were the most practical to use and which were the best mechanical equipment and process controls to use. In 1963, Maier published the first comprehensive book of the technical aspects of fluoridation, the Manual of Water Fluoridation Practices. In 1972, Bellack, then with the U.S. Environmental Protection Agency, published the Fluoridation Engineering Manual, which is still widely used today.

Dental Benefits

• The early studies showed that children who had from birth drank water containing optimal fluoride had 30-60 percent fewer cavities. Current data on dental caries show that the incidence of dental caries is reduced by 20-40 percent in the mixed dentition of children (ages 8-12) and 15-35 percent in the permanent dentition of adolescents (ages 14-17). Fluoridation does not only benefit children, it reduces coronal caries in adults by as much as 35 percent in fluoridated communities. The benefits of fluoride last a lifetime.

• There is strong evidence that water fluoridation not only makes the tooth more resistant to bacterial acids, but it inhibits the growth of certain kinds of bacteria that produce these acids. Fluoride actually promotes the demineralization of the tooth, causing a reversal process of tooth decay after it has already begun. The actual mechanism for the incorporation of the fluoride ion in the tooth and bone is not well known. However, it is known that the fluoride ion replaces the hydroxyl ion (OH-) in the crystal lattice in the enamel, resulting in a stronger tooth. In addition, several studies have evaluated the effect of discontinuing water fluoridation; after 2-6 years, the prevalence of dental caries had risen as high as 84 percent in school-age children, therefore, establishing a causal relationship between optimal concentrations of fluoride in drinking water and caries-resistant teeth.

Community Water Fluoridation

• According to the 1992 Fluoridation Census published by the Centers for Disease Control and Prevention (CDC), approximately 144 million Americans --- 55.8 percent of the total U.S. population and 62.1 percent of the population on public water supplies --- are served by drinking water containing optimal or above levels of fluoride. Despite the benefits of community water fluoridation, only 14,351 public water systems are fluoridated. In contrast, approximately 46,000 public water systems, serving more than one-third of the U.S. population, are not fluoridated. Since the introduction of community water fluoridation in 1945, the U.S. population receiving the benefits of water fluoridation has generally grown with the overall population growth and with the growth of the population on public water systems. One of the oral health objectives contained in Healthy People 2000, which outlines the disease prevention and health promotion objectives for the nation, proposes to increase to at least 75 percent the proportion of people served by community water systems providing optimal levels of fluoride. To achieve this goal, approximately 30 million people must gain access to the benefits of fluoride through the addition of community water fluoridation to their public water systems.

State Mandate and Ranking

• Fluoridation is mandatory in 8 states: Connecticut (1965), Georgia (1973), Illinois (1967), Michigan (1968), Minnesota (1967), Nebraska (1973), Ohio (1969), and South Dakota (1969). Six of these states have restrictions in their laws that limit the scope of the mandate; however, the two other states, Minnesota and Illinois, have mandated that all public water supplies be fluoridated. According to the 1992 CDC Fluoridation Census, nine of the states with the lowest percentage of population on public systems using fluoridated water are in the western one-third of the country (Washington, Idaho, Wyoming, Montana, Oregon, Arizona, California, Nevada, and Utah). Other low ranking states include Kansas, New Hampshire, New Jersey, Mississippi, and Hawaii. Four of the five largest U.S. cities (New York, Chicago, Philadelphia, and Detroit) were fluoridated between 1950 and 1960. The fifth, Los Angeles, with a population of 3 million, is not fluoridated. Twenty-one states meet the Healthy People 2000 objective of having at least 75 percent of their population on public water supplies that receive the benefits of fluoridated drinking water.

Controversies

• Community water fluoridation in the 1990's continues to be a political and legal issue in the public health arena. From a scientific and public health perspective, community water fluoridation is not controversial. There is a broad consensus among scientists, health professionals, and the courts that water fluoridation is safe, cost effective, practical, equitable, and does not violate individual rights guaranteed in the U.S. Constitution. Recently, statewide ballots to prohibit fluoridation have surfaced in Oregon, Washington, and Utah. Also, over the last decade, groups who oppose water fluoridation have:
  1. Made attempts to rescind fluoridation in communities already fluoridated;
  2. Introduced legislative bills to allow local option for fluoridation in those states with statewide mandates; and
  3. Initiated state and local litigations.

• Opponents of fluoridation have used many of the popular phrases that have been alarming to the public and effective in defeating fluoridation efforts, such as "violation of personal freedom," "forced medication," "Communist plot," and "an abuse of 'police power.'" The legal validity of fluoridation has been repeatedly tested and universally affirmed by the court of last resort in the United States over the past decade. Over a dozen cases reached the U.S. Supreme Court between 1954 and 1984, but none were actually heard by the court. Either the cases were dismissed for lack of a substantial federal question, or the court denied the writ of certiorari for which no reason need be given.

• In 1980, 41 fluoridation referenda were held in the United States; fluoridation was disapproved in 33 of these and approved in only eight. Between 1977 and 1982, about 25 percent of the ballot measures on fluoridation were approved. Although much progress has been made in water fluoridation over the last 45 years, it is important that supporters of fluoridation understand various factors that often result in defeat of fluoridation efforts. These factors include, but are not limited to:
  • Public apathy and distrust in government.
  • Failure to effectively educate the public on the scientific and sociopolitical aspects of water fluoridation.
  • Timing and readiness of the community to consider the adoption of fluoridation as a preventive oral health measure.
  • Failure of health professionals to treat the situation as a "political" campaign.
  • Failure of supporters of fluoridation to organize and prepare countererresponses early enough to refute opponents claims.
  • Failure to word the ballot succinctly to avoid confusion by the voter.

• Fluoridation has been linked with many diseases and conditions (from constipation in dogs to cancer in humans), none of which has ever shown to be valid.

Toward the Year 2000

• If the year 2000 fluoridation goal is to be met, there must be a collaborative partnership established at local, state, federal, and national levels to do the following:
  • Develop and implement a plan of action to maintain efficacy of water fluoridation as a proven public health measure.
  • Organize and enlist the support of other state and federal organizations that have an influence in guiding the development of public health policies and bringing about social change.
  • Effectively translate fluoridation information into languages for all racial and ethnic groups.
  • Develop new and innovative strategies to meet the challenges of fluoridation opponents, both past and present.
  • Develop a national clearinghouse for fluoridation materials, which include the sociopolitical, legal, medical, dental, scientific, and engineering aspects of community water fluoridation.
  • Develop a national surveillance system to collect, analyze, and evaluate risk factor data related to fluorides.
  • Create a national work group charged with the responsibility of developing a strategic plan to implement a national policy that would require all public water systems serving more than a population of 50,000 to fluoridate their water supplies.
  • Support legislation to fund community water fluoridation.

• Finally, these plans of action must also be accompanied by a consorted effort to eliminate the general public's misconceptions of water fluoridation in order to ensure the public's acceptance of water fluoridation as the practical and effective means of preventing dental caries.

Bibliography

Bonnie C. Dyck, RDH, MPH
Bonnie Dyck received her Diploma of Dental Hygiene from Meharry Medical College in Nashville, Tennessee and her MPH degree from the University of Tennessee, Knoxville. She is currently working with the California Department of Health Services, Dental Health Section, as the state fluoridation coordinator. She is also a public health advisor with the Centers for Disease Control and Prevention. She conducts a series of fluoridation seminars during the winter quarter at the University of California, San Francisco, School of Dentistry.

Additional reading:

• Ripa LW: A half-century of community water fluoridation in the United States: Review and commentary. J. Public Health Dent 53(1):17-44, 1993.
• Dodge CH, Tiemann ME: Fluoridation of Public Drinking Water: Issues of Health Benefits and Risks.. Congressional Research Service, Library of Congress. September 1, 1992.
• Grembowski D, Fiset L, Spadafora A: How fluoridation affects adult dental caries: Systemic and topical effects are explored. JADA 123(February):49-54, 1992.
• Newbrun E: Effectiveness of water fluoridation. J Public Health Dent 49(5 Spec No.):279-89, 1989.
• Kaminsky LS, Mahoney MC, Leah J, et al.: Critical Reviews of Oral Bio Med 1(4):261-81, 1990.
• U.S. Public Health Service, Committee to Coordinate Environmental Health and Related Programs. Ad Hoc Subcommittee on Fluoride: Review of Fluoride Benefits and Risks Washington, DC, Public Health Service Department and Human Services, 1991.