 |
Perspectives in Disease Prevention and Health Promotion
Dental Caries and Community Water
Fluoridation Trends -- United States
One of the 12 fluoridation and dental health objectives
identified
in the U.S. Public Health Service's Objectives for the Nation (1)
states: By 1990, the number of 9-year-old children who have had
caries in their permanent teeth should be decreased to 60% (40%
would
be caries-free). In 1971-1973, 71% of these children had caries in
their permanent teeth. The National Caries Prevalence Survey,
conducted by the National Institute of Dental Research (NIDR) in
1979-1980 (2), reported that 49% of these children have had decay
in
their permanent teeth, demonstrating this objective has been
achieved. The survey also reported that 89% of 17-year-olds have
had
dental caries (2). Although 37% of children aged 5-17 years were
caries-free, approximately 24% of children in the same age group
have
had five or more decayed, missing (due to caries), and/or filled
permanent teeth (Figure 1).
When the NIDR survey is compared with an earlier, similar
survey
by the National Center for Health Statistics, the prevalence of
dental
decay among school-aged children appears to have been significantly
reduced since 1973 (Figure 2) (2,3). The availability of fluorides
from a number of sources, including community and school water
fluoridation, fluoride tablets and drops, fluoride rinses and
dentifrices, and clinically applied fluorides, have contributed to
the
decline in dental caries. It is difficult to attribute this
decline
to one specific modality, and the effects are not arithmetically
additive. However, the combination of systemic and topical
fluorides
has contributed greatly to improved oral health in the United
States.
In 1985, approximately 20,000 employed adults and 5,000 older
adults
at senior citizen centers will be surveyed as part of an NIDR
National
Survey of Adult Dental Health. Oral health status and data on
treatment needs from this survey will be available in 1987.
Although community water fluoridation remains the most
effective
and practical means of preventing and controlling dental caries,
nearly half the U.S. population still does not have access to
optimally fluoridated water. The optimal amount of fluoride
necessary
to reduce the most dental decay, with the least amount of risk of
dental fluorosis (discoloration of the enamel), is 0.7-1.2 mg/l
(0.7-1.2 parts fluoride per 1 million parts water) (4). Fluoride
occurs naturally in most waters but usually at less than optimal
levels. Since it is assumed that people in warmer climates drink
more
water than people in colder climates, the optimal level is lowest
in
the southernmost part of the United States. Therefore, the optimal
fluoride level is calculated based on the annual average of maximum
daily air temperature (5).
Since the introduction in 1945 of the practice of adjusting
fluoride levels in community water systems, the number of people
with
access to water with dentally significant levels of fluoride (0.7
parts per million (ppm) or higher) has increased steadily to an
estimated 123 million in 1983--approximately 52.2% of the total
U.S.
population (6,7). It is impractical to expect 100% coverage,
because
a portion of the population is not served by public water supplies
(approximately 6% in 1983) (6,8). However, in some of these water
supplies, fluoride occurs naturally at optimal levels, and the
number
of people served by naturally fluoridated water has remained fairly
constant at approximately 10.7 million (Figure 3) (6,7). Excluding
this portion, the estimated percent of the population on public
water
supplies receiving fluoridated water was 56.5% in 1983.
However, the number of people served by public water supplies
is
increasing (Figure 3). This trend can be explained by increased
urbanization of the U.S. population. The population served by
public
water supplies varies from state to state and ranges from 29% in
Oregon to 99% in Illinois and Maryland. The population served by
public water supplies in Washington, D.C., is 100% (6,8).
Another national fluoridation and dental health objective for
1990
states: At least 95% of the population on community water systems
should be receiving the benefits of optimally fluoridated water.
Of
the 60,000 public water supplies in the United States, only about
8,000 are fluoridated (6,8). Approximately 46,000 of these systems
serve populations of under 1,000, and 150 systems serve populations
of
more than 100,000 (6,8). The public water systems of nine of the
50
largest cities in the United States are not fluoridated: Los
Angeles,
San Diego, and San Jose, California; Phoenix, and Tucson, Arizona;
San
Antonio, Texas; Portland, Oregon; Honolulu, Hawaii; and Newark, New
Jersey (9). Past experience has shown that the length of time
needed
to implement fluoridation in a given community is not necessarily
related to the size of the community but rather to other factors,
such
as how the decision to fluoridate is made (e.g., city council,
referendum), and the effectiveness of public health education
programs
about the benefits of fluoridation.
The maintenance of the optimal level of fluoride is critical
once
a water system is fluoridated. It has been shown that the dental
benefits from fluoridated water are significantly reduced if
fluoride
levels drop below the optimal concentration (10-12).
The results of the National Preventive Dentistry Demonstration
Program conducted by The Robert Wood Johnson Foundation indicate
that,
"At an estimated cost of less than $1 per child per year,
fluoridation
remains society's least expensive and most effective caries
preventive
measure" (13).
Reported by Dental Disease Prevention Activity, Center for
Prevention
Svcs, CDC.
References
U.S. Public Health Service. Promoting health/preventing
disease:
objectives for the nation. Washington, D.C.: U.S. Department
of
Health and Human Services, 1980.
National Institutes of Health, National Institute of Dental
Research, National Caries Program. The prevalence of dental
caries in United States children, 1979-1980; the national
caries
prevalence survey. Washington, D.C.: U.S. Public Health
Service,
1981. (NIH publication no. 82-2245).
National Center for Health Statistics, National Health Survey,
1971-1973. Unpublished data, 1978.
Galagan DJ, Vermillion JR. Determining optimum fluoride
concentrations. Public Health Rep, 1957;72:491-3.
Galagan DJ. Climate and controlled fluoridation. Am Dent
Assoc J
1953;47:159-70.
CDC. Fluoridation census, 1980. June 1984.
CDC. Unpublished data.
U.S. Environmental Protection Agency. Facilities and
population
by primary water supply source. Washington, D.C.: U.S.
Environmental Protection Agency, 1984.
CDC. Over 115 million people on fluoridated water supplies in
U.S. as of December 31, 1980. Atlanta, Georgia: Centers for
Disease Control, April 1984.
Chrietzberg JE, Lewis JE. Effect of modifying sub-optimal
fluoride concentration in public water supply. Ga Dent Assoc
J,
July 1962:12-7.
Sweeney EA, Murphy TJ, Steinhurst J, Taylor FB. Experiences in
maintaining fluoride concentrations at optimal level in
Massachusetts public water supplies. Mass Dent Soc J, Summer
1978:147-55.
American Dental Association. Omaha's fluoridation from .6 to 1
ppm reduces caries 44%. Am Dent Assoc News, 1980.
The Robert Wood Johnson Foundation. Special report: national
preventive dentistry demonstration program. Chicago: Robert
Wood
Johnson Foundation, 1983.
Disclaimer
All MMWR HTML documents published before January 1993 are electronic conversions from ASCII text into HTML. This conversion may have resulted in character translation or format errors in the HTML version. Users should not rely on this HTML document, but are referred to the original MMWR paper copy for the official text, figures, and tables. An original paper copy of this issue can be obtained from the Superintendent of Documents, U.S. Government Printing Office (GPO), Washington, DC 20402-9371; telephone: (202) 512-1800. Contact GPO for current prices. **Questions or messages regarding errors in formatting should be addressed to mmwrq@cdc.gov. Page converted: 08/05/98
|
|
