Related Articles

Background

Fluoridation of public water supplies remains the key potential strategy for prevention of dental caries. The water supplies of many remote Indigenous communities do not contain adequate levels of natural fluoride. The small and dispersed nature of communities presents challenges for the provision of fluoridation infrastructure and until recently smaller settlements were considered unfavourable for cost-effective water fluoridation. Technological advances in water treatment and fluoridation are resulting in new and more cost-effective water fluoridation options and recent cost analyses support water fluoridation for communities of less than 1,000 people.

Methods

Small scale fluoridation plants were installed in two remote Northern Territory communities in early 2004. Fluoride levels in community water supplies were expected to be monitored by local staff and by a remote electronic system. Site visits were undertaken by project investigators at commissioning and approximately two years later. Interviews were conducted with key informants and documentation pertaining to costs of the plants and operational reports were reviewed.

Results

The fluoridation plants were operational for about 80% of the trial period. A number of technical features that interfered with plant operation were identified and addressed though redesign. Management systems and the attitudes and capacity of operational staff also impacted on the effective functioning of the plants. Capital costs for the wider implementation of these plants in remote communities is estimated at about $US94,000 with recurrent annual costs of $US11,800 per unit.

Conclusion

Operational issues during the trial indicate the need for effective management systems, including policy and funding responsibility. Reliable manufacturers and suppliers of equipment should be identified and contractual agreements should provide for ongoing technical assistance. Water fluoridation units should be considered as a potential priority component of health related infrastructure in at least the larger remote Indigenous communities which have inadequate levels of natural fluoride and high levels of dental caries.

It has been 40 years since the first community in the United States added a regulated amount of fluoride to its public water supply to prevent tooth decay. Despite the proven benefits of fluoride, today only 61 percent of the U.S. population on public water supplies receives fluoridated water. Progress in fluoridating water is impeded by antifluoridation campaigns and a change in the way Federal funds are allocated for State and local fluoridation programs. Despite profluoridation efforts by the Public Health Service, American Dental Association, and other organizations, the well-publicized claims of fluoride hazards by opponents have prevented many communities from initiating water fluoridation and have caused other communities to discontinue their programs. The law and half a century of research are on the side of fluoridation, as are new scientific findings indicating that optimal amounts of fluoride may reduce the incidence or severity of osteoporosis.

Community water fluoridation has served the American public extremely well as the cornerstone of dental caries prevention activities for 45 years. The dental and general health benefits associated with the ingestion of water-borne fluorides have been well known by researchers for an even longer period. Continued research has repeatedly confirmed the safety, effectiveness, and efficiency of community water fluoridation in preventing dental caries for Americans regardless of age, race, ethnicity, religion, educational status, or socioeconomic level. Despite the obvious benefits associated with this proven public health measure, slow progress has been made toward achieving the 1990 national fluoridation objectives as listed in "Promoting Health/Preventing Disease: Objectives for the Nation." This paper documents the lagging pace of community fluoridation by reviewing and analyzing data reported in "Fluoridation Census, 1985," a document published in late 1988 by the Public Health Service's Centers for Disease Control. Failure to attain the 1990 objectives is attributable to a combination of circumstances, including their low priority within many local, State, and Federal health agencies, inadequate funding at all levels of government, lack of a coordinated and focused national fluoridation effort, failure of most States to require fluoridation, lack of Federal legislation mandating fluoridation, general apathy of most health professional organizations toward fluoridation, misconceptions by the public about effectiveness and safety and, finally, unrelenting opposition by a highly vocal minority of the lay public.(ABSTRACT TRUNCATED AT 250 WORDS)

A comparison was made of the dental health of children aged 4-5 and 9-10 in two Scottish towns, one with fluoridated drinking water and the other without. Striking differences were observed. A 44% reduction in decayed, missing, and filled deciduous teeth was found in 4-5 year-olds in the fluoridated compared with the non-fluoridated town and a 50% reduction in decayed, missing, and filled permanent teeth was recorded for the 9-10-year-olds. Larger percentage differences were found for the anterior teeth: a 65% reduction in deciduous incisors and canines, and an 81% reduction in permanent incisors and canines. Fluoridation of public water supplies in urban areas of Scotland would be a safe and effective way of dramatically improving dental health.

Background

The addition of the chemical fluorine to the water supply, called water fluoridation, reduces dental caries by making teeth more resistant to demineralisation and more likely to remineralise when initially decayed. This process has been implemented in more than 30 countries around the world, is cost-effective and has been shown to be efficacious in preventing decay across a person's lifespan. However, attempts to expand this major public health achievement in line with Australia's National Oral Health Plan 2004–2013 are almost universally met with considerable resistance from opponents of water fluoridation, who engage in coordinated campaigns to portray water fluoridation as ineffective and highly dangerous.

Discussion

Water fluoridation opponents employ multiple techniques to try and undermine the scientifically established effectiveness of water fluoridation. The materials they use are often based on Internet resources or published books that present a highly misleading picture of water fluoridation. These materials are used to sway public and political opinion to the detriment of public health. Despite an extensive body of literature, both studies and results within studies are often selectively reported, giving a biased portrayal of water fluoridation effectiveness. Positive findings are downplayed or trivialised and the population implications of these findings misinterpreted. Ecological comparisons are sometimes used to support spurious conclusions. Opponents of water fluoridation frequently repeat that water fluoridation is associated with adverse health effects and studies are selectively picked from the extensive literature to convey only claimed adverse findings related to water fluoridation. Techniques such as "the big lie" and innuendo are used to associate water fluoridation with health and environmental disasters, without factual support. Half-truths are presented, fallacious statements reiterated, and attempts are made to bamboozle the public with a large list of claims and quotes often with little scientific basis. Ultimately, attempts are made to discredit and slander scientists and various health organisations that support water fluoridation.

Summary

Water fluoridation is an important public health initiative that has been found to be safe and effective. Nonetheless, the implementation of water fluoridation is still regularly interrupted by a relatively small group of individuals who use misinformation and rhetoric to induce doubts in the minds of the public and government officials. It is important that public health officials are aware of these tactics so that they can better counter their negative effect.

OBJECTIVE: To examine the effect of water fluoridation, both artificial and natural, on dental decay, after socioeconomic deprivation was controlled for. DESIGN: Ecological study based on results from the NHS dental surveys in 5 year olds in 1991-2 and 1993-4 and Jarman underprivileged area scores from the 1991 census. SETTING: Electoral wards in three areas: Hartlepool (naturally fluoridated), Newcastle and North Tyneside (fluoridated), and Salford and Trafford (non-fluoridated). SUBJECTS: 5 year old children (n = 10,004). INTERVENTION: Water fluoridation (artificial and occurring naturally). MAIN OUTCOME MEASURE: Ward tooth decay score (score on the "decayed, missing, and filled tooth index" for each electoral ward). RESULTS: Multiple linear regression showed a significant interaction between Jarman score for ward, mean number of teeth affected by decay, and both types of water fluoridation. This confirms that the more deprived an area, the greater benefit derived from fluoridation, whether natural or artificial (R2 = 0.84, P < 0.001). At a Jarman score of zero (national mean score) there was a predicted 44% reduction in decay in fluoridated areas, increasing to a 54% reduction in wards with a Jarman score of 40 (very deprived). The area with natural fluoridation (at a level of 1.2 parts per million-higher than levels in artificially fluoridated areas) had a 66% reduction in decay, with a 74% reduction in wards with a Jarman score of 40. CONCLUSION: Tooth decay is confirmed as a disease associated with social deprivation, and the more socially deprived areas benefit more from fluoridation. Widespread water fluoridation is urgently needed to reduce the "dental health divide" by improving the dental health of the poorer people in Britain.

Tooth decay, which affects 95 percent of Americans, is our most common health problem, costing an estimated +2 billion yearly for treatment. By the time children reach 17 years of age, 94 percent have experienced caries and 36 percent have lost one or more permanent teeth due to caries. Dental disease prevention embodies the spectrum of many activities from the fluoridation of community and school water supplies to the dental health education of the child and adult. At this stage of our knowledge, the most effective and cost-beneficial intervention is fluoridation. Fluoridation can reduce the incidence of dental caries by about 65 percent, reduce the need for multiple surface fillings, crowns and extractions, and significantly increase the number of children who are completely free of cavities. No other public health measure is as effective in building a decay-resistant tooth while being available to all without regard to education or socio-economic background. The number of people served by fluoridated water systems has increased steadily since its introduction. Currently, however, less than half of all Americans have access to fluoridated water. In areas where community water supplies are not fluoridated, school drinking water is seldom fluoridated despite evidence supporting the efficacy of this procedure.

This field study included the whole population of children aged 10–15 years (77 from a 0.19 mg/L F area; 89 from a 3.00 mg/L F area), with similar nutritional, dietary habits and similar ethnic and socioeconomic status. The fluoride concentration in the drinking water, the bone mineral content, the bone density and the degree of dental fluorosis were determined. The left radius was measured for bone width, bone mineral content, and bone mineral density. The mean fluorosis score was 1.3 in the low fluoride area and 3,6 in the high fluoride area. More than half the children in the low fluoride area had no fluorosis (scores 0 and 1) while only 5% in the high fluoride area had none. Severe fluorosis (30%) was only observed in the high fluoride area. The Wilcoxon Rank Sum Test indicated that fluorosis levels differed significantly (p < 0.05) between the two areas. No relationships were found between dental fluorosis and bone width or between fluorosis and bone mineral density in the two areas (Spearment Rank correlations). A significant increase in bone width was found with age but no differences amongst and boys and girls. A significant positive correlation was found in the high fluoride area between bone mineral density over age. In the 12-13 and 13-14 year age groups in the high fluoride area, girls had higher bone mineral densities. However, a significant negative correlation (p<0.02) was found for the low fluoride area (0.19 mg/L F) over age.

Background & objectives:

Endemic fluorosis resulting from high fluoride concentration in groundwater is a major public health problem in India. This study was carried out to measure and compare the prevalence of dental fluorosis and dental caries in the population residing in high and normal level of fluoride in their drinking water in Vadodara district, Gujarat, India.

Methods:

A cross-sectional study was conducted in Vadodara district, six of the 261 villages with high fluoride level and five of 1490 with normal fluoride level in drinking water were selected. The data collection was made by house-to-house visits twice during the study period.

Results:

The dental fluorosis prevalence in high fluoride area was 59.31 per cent while in normal fluoride area it was 39.21 per cent. The prevalence of dental caries in high fluoride area was 39.53 per cent and in normal fluoride area was 48.21 per cent with CI 6.16 to 11.18. Dental fluorosis prevalence was more among males as compared to females. Highest prevalence of dental fluorosis was seen in 12-24 yr age group.

Interpretation & conclusions:

The risk of dental fluorosis was higher in the areas showing more fluoride content in drinking water and to a lesser degree of dental caries in the same area. High fluoride content is a risk factor for dental fluorosis and problem of dental fluorosis increased with passage of time suggesting that the fluoride content in the water has perhaps increased over time. Longitudinal studies should be conducted to confirm the findings.

Naturally occurring fluorides of varying levels made possible a study do determine if continuous, lifetime use of home drinking water fluoridated to optimum levels combined with the use of school fluoridated water beginning at school age causes objectionable levels of dental fluorosis as defined by Dr. H. Trendley Dean in 1936. Examinations were performed on 120 children who had fluoride concentrations in home well water ranging from 0.1 to 6.5 ppm and attended a school with a private water source containing 4.5 ppm natural fluoride (5.6 times the optimum for community fluoridation in the area). Fluorosis scores were calculated for each of four groups formed according to fluoride concentrations in home water supplies. The group with an average concentration of 0.87 ppm was found to have a Community Index of Dental Fluorosis well within Dean's normal limits. The results suggest that children consuming water at home containing the optimal fluoride concentration and drinking water at school containing the recommended fluoride level (4.5 times the optimum) are not at risk to dental fluorosis that impairs appearance. If this finding is corroborated by future clinical studies, the target population for school fluoridation can be expanded and the administration of these programs facilitated.

Objectives

We tested a dental health program in remote Aboriginal communities of Australia's Northern Territory, hypothesizing that it would reduce dental caries in preschool children.

Methods

In this 2-year, prospective, cluster-randomized, concurrent controlled, open trial of the dental health program compared to no such program, 30 communities were allocated at random to intervention and control groups. All residents aged 18–47 months were invited to participate. Twice per year for 2 years in the 15 intervention communities, fluoride varnish was applied to children's teeth, water consumption and daily tooth cleaning with toothpaste were advocated, dental health was promoted in community settings, and primary health care workers were trained in preventive dental care. Data from dental examinations at baseline and after 2 years were used to compute net dental caries increment per child (d3mfs). A multi-level statistical model compared d3mfs between intervention and control groups with adjustment for the clustered randomization design; four other models used additional variables for adjustment.

Results

At baseline, 666 children were examined; 543 of them (82%) were re-examined 2 years later. The adjusted d3mfs increment was significantly lower in the intervention group compared to the control group by an average of 3.0 surfaces per child (95% CI = 1.2, 4.9), a prevented fraction of 31%. Adjustment for additional variables yielded caries reductions ranging from 2.3 to 3.5 surfaces per child and prevented fractions of 24–36%.

Conclusions

These results corroborate findings from other studies where fluoride varnish was efficacious in preventing dental caries in young children.

OBJECTIVE: To prevent fluorosis caused by excessive fluoride ingestion by revising recommendations for fluoride intake by children. OPTIONS: Limiting fluoride ingestion from fluoridated water, fluoride supplements and fluoride dentifrices. OUTCOMES: Reduction in the prevalence of dental fluorosis and continued prevention of dental caries. EVIDENCE: Before the workshop, experts prepared comprehensive literature reviews of fluoride therapies, fluoride ingestion and the prevalence and causes of dental fluorosis. The papers, which were peer-reviewed, revised and circulated to the workshop participants, formed the basis of the workshop discussions. VALUES: Recommendations to limit fluoride intake were vigorously debated before being adopted as the consensus opinion of the workshop group. BENEFITS, HARMS AND COSTS: Decrease in the prevalence of dental fluorosis with continuing preventive effects of fluoride use. The only significant cost would be in preparing new, low-concentration fluoride products for distribution. RECOMMENDATIONS: Fluoride supplementation should be limited to children 3 years of age and older in areas where there is less than 0.3 ppm of fluoride in the water supply. Children in all areas should use only a "pea-sized" amount of fluoride dentifrice no more than twice daily under the supervision of an adult. VALIDATION: These recommendations are almost identical to changes to recommendations for the use of fluoride supplements recently proposed by a group of European countries. SPONSORS: The workshop was organized by Dr. D. Christopher Clark, of the University of British Columbia, and Drs. Hardy Limeback and Ralph C. Burgess, of the University of Toronto, and funded by Proctor and Gamble Inc., Toronto, the Medical Research Council of Canada and Health Canada (formerly the Department of National Health and Welfare). The recommendations were formally adopted by the Canadian Dental Association in April 1993.

This paper addresses a number of areas related to how effectively science and technology have met Healthy People 2010 goals for tooth decay prevention. In every area mentioned, it appears that science and technology are falling short of these goals. Earlier assessments identified water fluoridation as one of the greatest public health accomplishments of the last century. Yet, failure to complete needed clinical and translational research has shortchanged the caries prevention agenda that incomplete at a critical juncture.

Science has firmly established the transmissible nature of tooth decay. However, there is evidence that tooth decay in young children is increasing although progress has been made in other age groups. Studies of risk assessment have not been translated into improved practice. Antiseptics, chlorhexidine varnish, and PVP-iodine may have value, but definitive trials are needed. Fluorides remain the most effective agents, but are not widely disseminated to the most needy. Fluoride varnish provides a relatively effective topical preventive for very young children, yet definitive trials have not been conducted. Silver diammine fluoride also has potential but requires study in the US. Data support effectiveness and safety of xylitol, but adoption is not widespread. Dental sealants remain a mainstay of public policy, yet after decades of research, widespread use has not occurred.

We conclude that research has established the public health burden of tooth decay, but insufficient research addresses the problems identified in the Surgeon General's Report. Transfer of technology from studies to implementation is needed to prevent tooth decay among children. This should involve translational research and implementation of scientific and technological advances into practice.

Introduction

Local, state, and national health policy makers require information on the economic burden of oral disease and the cost-effectiveness of oral health programs to set policies and allocate resources. In this study, we estimate the cost savings associated with community water fluoridation programs (CWFPs) in Colorado and potential cost savings if Colorado communities without fluoridation programs or naturally high fluoride levels were to implement CWFPs.

Methods

We developed an economic model to compare the costs associated with CWFPs with treatment savings achieved through averted tooth decay. Treatment savings included those associated with direct medical costs and indirect nonmedical costs (i.e., patient time spent on dental visit). We estimated program costs and treatment savings for each water system in Colorado in 2003 dollars. We obtained parameter estimates from published studies, national surveys, and other sources. We calculated net costs for Colorado water systems with existing CWFPs and potential net costs for systems without CWFPs. The analysis includes data for 172 public water systems in Colorado that serve populations of 1000 individuals or more. We used second-order Monte Carlo simulations to evaluate the inherent uncertainty of the model assumptions on the results and report the 95% credible range from the simulation model.

Results

We estimated that Colorado CWFPs were associated with annual savings of $148.9 million (credible range, $115.1 million to $187.2 million) in 2003, or an average of $60.78 per person (credible range, $46.97 to $76.41). We estimated that Colorado would save an additional $46.6 million (credible range, $36.0 to $58.6 million) annually if CWFPs were implemented in the 52 water systems without such programs and for which fluoridation is recommended.

Conclusion

Colorado realizes significant annual savings from CWFPs; additional savings and reductions in morbidity could be achieved if fluoridation programs were implemented in other areas.

The benefits to be expected from the adjustment of fluoride levels in drinking water have been studied in great depth, but for the most part only with respect to changes from negligible concentrations to approximately 1.0 ppm. This study makes use of previously gathered data on fluoride concentration in domestic water supplies, the average decayed, missing, and filled teeth (DMFT) scores of the 12- to 14-year-old children, and temperature data in conjunction with linear mathematical models to estimate the effect on DMFT of changes in fluoride concentrations from levels above 0.1 ppm to ideal levels. The results of the analyses indicate that the endemic levels of fluoride in a community water supply play a major role in determining the relative benefit of adjusting that water supply to an ideal level of fluoride. If a rational policy decision is to be made with respect to fluoridation for a given community, the endemic fluoride levels must be considered in conjunction with such factors as population size and the anticipated cost to initiate and maintain the program.

The National Institute of Dental Research (NIDR) was created by President Harry S Truman on June 24, 1948, as the third of the National Institutes of Health. NIDR's legislation contained the mandate to conduct research and research training to improve oral health. An impetus for federally funded dental research was the finding in World War II that the major cause of rejection for military service was missing teeth. Because of the population's widespread tooth decay problems, early NIDR research focused on eliminating dental caries. NIDR scientists confirmed the safety and effectiveness of the use of fluoride in tooth decay prevention, leading to one of the nation's most successful public health efforts, community water fluoridation. During the past 40 years, NIDR scientists have provided research advances and fostered technologies which changed the philosophy and practice of dentistry and brought dental sciences into the mainstream of biomedical research. Dental researchers contribute to studies of such diseases and problems as AIDS, cancer, arthritis, cystic fibrosis, diabetes, herpes, craniofacial anomalies, pain, and bone and joint disorders. NIDR's 40th anniversary in 1988 recognizes its continuing commitment to oral disease prevention and health research, and to achieving the goal of people maintaining their natural dentition for a lifetime.

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Objective:

To assess the relationship between exposure to different drinking water fluoride levels and children's intelligence in Madhya Pradesh state, India.

Materials and Methods:

This cross-sectional study was conducted among 12-year-old school children of Madhya Pradesh state, India. The children were selected from low (< 1.5 parts per million) and high (≥1.5 parts per million) fluoride areas. A questionnaire was used to collect information on the children's personal characteristics, residential history, medical history, educational level of the head of the family, and socioeconomic status of the family. Levels of lead, arsenic, and iodine in the urine and the levels of fluoride in the water and urine were analyzed. The children's intelligence was measured using Raven's Standard Progressive Matrices. Data analysis was done using the chi-square, one way analysis of variance, simple linear regression, and multiple linear regression tests. P value <0.05 was considered statistically significant.

Results:

Differences in participant's sociodemographic characteristics, urinary iodine, urinary lead, and urinary arsenic levels were statistically not significant (P>0.05). However, a statistically significant difference was observed in the urinary fluoride levels (P 0.000). Reduction in intelligence was observed with an increased water fluoride level (P 0.000). The urinary fluoride level was a significant predictor for intelligence (P 0.000).

Conclusion:

Children in endemic areas of fluorosis are at risk for impaired development of intelligence.

Objective

To assess the effects of provided fluoride-safe drinking-water for the prevention and control of endemic fluorosis in China.

Design

A national cross-sectional study in China.

Setting

In 1985, randomly selected villages in 27 provinces (or cities and municipalities) in 5 geographic areas all over China.

Participants

Involved 81 786 children aged from 8 to 12 and 594 698 adults aged over 16.

Main outcome measure

The prevalence of dental fluorosis and clinical skeletal fluorosis, the fluoride concentrations in the drinking-water in study villages and in the urine of subjects.

Results

The study showed that in the villages where the drinking-water fluoride concentrations were higher than the government standard of 1.2 mg/l, but no fluoride-safe drinking-water supply scheme was provided (FNB areas), the prevalence rate and index of dental fluorosis in children, and prevalence rate of clinical skeletal fluorosis in adults were all significantly higher than those in the historical endemic fluorosis villages after the fluoride-safe drinking-water were provided (FSB areas). Additionally, the prevalence rate of dental fluorosis as well as clinical skeletal fluorosis, and the concentration of fluoride in urine were found increased with the increase of fluoride concentration in drinking-water, with significant positive correlations in the FNB areas. While, the prevalence rate of dental fluorosis and clinical skeletal fluorosis in different age groups and their degrees of prevalence were significantly lower in the FSB areas than those in the FNB areas.

Conclusions

The provision of fluoride-safe drinking-water supply schemes had significant effects on the prevention and control of dental fluorosis and skeletal fluorosis. The study also indicated that the dental and skeletal fluorosis is still prevailing in the high-fluoride drinking-water areas in China.

Objective

This communication examines the combined effect of topical PVP-iodine plus fluoride varnish in prevention of tooth decay in erupting first permanent molars in an on-going public health program.

Methods

The evaluation employed a retrospective cohort design with two groups of children 60–83 months. Cohort 1 (2004–05) received three times per school year topical fluoride varnish, and Cohort 2 (2008–09) received topical application of 10% PVP-iodine followed at each visit with topical fluoride varnish. The children were examined clinically at the beginning and end of the school year.

Results

The proportion of children with caries-free first permanent molars in Cohort 2 (PVP-iodine plus fluoride varnish) was .883 and was greater than that in Cohort 1 (varnish), which was .785 (Chi-square=1.000E1, df 1, p<.002).

Conclusions

This evaluation of an on-going dental public health program adds evidence that topical antiseptics applied at the same time as fluoride varnish are more effective than varnish alone. Randomized trials are needed.

Fluoridation of public water supplies is the best method of preventing dental caries. Yet, many water systems do not maintain the optimal concentration of fluoride. The Community Fluoridation Compliance Index was developed to provide retrospective and prospective information on water systems in complying with local and State standards. This index permits flexibility in the amounts of optimal fluoride concentration and the frequency of fluoride sample testing. In addition, the index can be modified to address the size of the population served by the water system. The index's components are reviewed, and its use is demonstrated on 50 water systems from Illinois and 50 from Ohio. Annual data from these two States show how this information can be used for targeting corrective action so that the population receives the greatest benefit from fluoridation. These findings suggest that the Community Fluoridation Compliance Index can be a useful administrative instrument for comparing relative compliance results. Further studies to determine its acceptance at the State and local levels are warranted.

Objective:

Prolonged excessive intake of fluoride during child’s growth and development stages has been associated with mental and physical problems. The aim of this study was to investigate the effect of excessive fluoride intake on the intelligence quotient (IQ) of children living in five rural areas in Makoo/Iran.

Materials and Methods:

In this cross-sectional study, 293 children aged 6–11 years were selected from five villages in Makoo with normal fluoride (0.8±0.3 ppm), medium fluoride (3.1±0.9 ppm) and high fluoride (5.2±1.1 ppm) in their water supplies. The IQ of each child was measured by the Raven’s test. Educational and residential information and the medical history of each child was recorded by a questionnaire completed by the parents. Data were analyzed by ANOVA test with a significance level of 0.05.

Results:

The mean IQ scores decreased from 97.77±18.91 for the normal fluoride group to 89.03±12.99 for the medium fluoride group and to 88.58±16.01 for the high fluoride group (P=0.001).

Conclusion:

Children residing in areas with higher than normal water fluoride levels demonstrated more impaired development of intelligence. Thus, children’s intelligence may be affected by high water fluoride levels.

Longitudinal microbiological examinations have been made of dental plaque from a site approximal to the upper central incisors of 10 8-year-old children living in an area with water fluoridation. Differential counts of viable bacteria, made using a selective medium containing various levels of fluoride (0 to 100 μg/ml) at pH levels of 7.0 to 5.5, demonstrated an effect of both pH and fluoride on the numbers and types of bacteria isolated. Strains of Streptococcus and Neisseria grew after only 16 h of incubation at pH levels as low as 6.0 with fluoride levels up to 50 μg/ml. The most commonly isolated streptococci were Streptococcus mitior and S. salivarius. S. mutans was isolated less frequently and was inhibited by 20 and 50 μg of fluoride per ml at pH 6.0 and 6.5, respectively. Veillonella strains were the most resistant isolates, being isolated after 16 h of incubation on media at pH 6.0 with 100 μg of fluoride per ml. Despite their known fluoride resistance, Actinomyces spp. were often only detected on the selective media after 72 h of incubation. The pH of the medium had a definite selective effect, as the number of colonies growing on the fluoride-free basal media at pH 6.0 was only 30% of that at pH 7.0. Representative strains of S. mutans, S. mitior, S. sanguis, and S. milleri were tested for their ability to utilize glucose at the pH and fluoride levels of the medium on which they were initially isolated. Fluoride reduced the initial glycolytic rate of the cells, but in 5 of the 13 strains tested the final amount of glucose used after 2 h of incubation was the same in the presence or absence of fluoride. The isolation of bacteria capable of growth in the presence of fluoride over a significant portion of the pH range that occurs in plaque in vivo could explain in part the finding that fluoride does not have a dramatic effect on the plaque community. Fluoride in plaque may reduce the ecological advantage afforded to aciduric S. mutans strains by carbohydrate substances. In the in vivo situation this could mean that, even with high carbohydrate intake, fluoride may permit S. mitior to compete with S. mutans within the plaque ecosystem.

OBJECTIVE: To determine the extent and confirm the cause of an August 1993 outbreak of acute fluoride poisoning in a small Mississippi community, thought to result from excess fluoride in the public water supply. METHODS: State health department investigators interviewed patrons of a restaurant where the outbreak first became manifest and obtained blood and urine samples for measurement of fluoride levels. State health department staff conducted a random sample telephone survey of community households. Public health environmentalists obtained water and ice samples from the restaurant and tap water samples from a household close to one of the town's water treatment plant for analysis. Health department investigators and town water department officials inspected the fluoridation system at the town's main water treatment plant. RESULTS: Thirty-four of 62 restaurant patrons reported acute gastrointestinal illness over a 24-hour period. Twenty of 61 households that used the community water supply reported one or more residents with acute gastrointestinal illness over a four-day period, compared with 3 of 13 households that did not use the community water supply. Restaurant water and ice samples contained more than 40 milligrams of fluoride per liter (mg/L), more than 20 times the recommended limit, and a tap water sample from a house located near the main treatment plant contained 200 mg/l of fluoride. An investigation determined that a faulty feed pump at one of the town's two treatment plants had allowed saturated fluoride solution to siphon from the saturator tank into the ground reservoir and that a large bolus of this overfluoridated water had been pumped accidentally into the town system. CONCLUSIONS: Correct installation and regular inspection and maintenance of fluoridation systems are needed to prevent such incidents.

This study was conducted to find out the level of oxidative stress and effect of supplementation of vitamin C, D and Calcium on levels of SOD, serum and urinary fluoride in children residing in endemic fluorosis area. For this the fluoride belt of Jaipur district was selected. The parameters selected were Super oxide dismutase, serum fluoride and urinary fluoride. The study was conducted on one hundred children, selected from four areas (25 from each area) consuming water containing 1.2, 2.4, 5.6 and 13.6 mg/l of fluoride. Drinking water fluoride, serum and urinary fluoride were measured by Ion selective electrode method. Serum SOD by Xanthine oxidase method using kit of Ransod (kit cat. No. SD125). The post treatment values showed a significant reduction in serum fluoride and SOD. Urinary fluoride levels increased significantly in post treatment stage. The results revealed a normal SOD levels in all groups but an increasing trend was observed with increasing fluoride concentration. Treatment with Calcium, Vitamin D and Vitamin C showed a significant reduction in serum fluoride and SOD and increase in urinary fluoride. A high positive correlation between pretreatment and post treatment group was observed in serum fluoride, SOD and urinary fluoride (P < 0.05). The study indicated an increasing oxidative stress in cases of fluorosis with increasing drinking water fluoride concentration. Treatment with Calcium, Vitamin D and Vitamin C resulted a significant reduction in serum fluoride and SOD and increase in urinary fluoride.

In three quarters of a century of observation and research, the effects of fluoride on dental caries and on general bodily health have been well documented. An expanding data base has allowed a firming up of the guidance and standards for appropriate and safe levels of naturally occurring fluorides for human consumption. Over time, through specific recommendations, the maximum fluoride concentrations deemed appropriate have been altered, but by a process of considered adjustment. Although the Public Health Service has been responsible for the formalization of many of the recommended standards, those recommendations have been based on research from many fronts. In the most recent reconsideration of the standards for natural fluoride, the most exhaustive and thoroughly documented review to date was done, incorporating review by representatives from State, Federal, and private programs. Although the specific example of the development of standards for natural fluoride is used, it should be illustrative of similar processes that are constantly underway in regard to substances and factors with a potential impact on the public's health. Expansion of the data base through research and scientific inquiry will lay the foundation for future reconsideration of the standards for naturally occurring fluorides.