Fluoride-deficient Communities Research Articles

Does fluoride in drinking water delay tooth eruption?

The objectives of this study are to determine the effect of fluoride exposure on permanent tooth eruption patterns as well as to understand its effect on caries attack rate by accounting for the number of erupted tooth surfaces. We analyzed data from the 1986-1987 National Survey of Oral Health of US Schoolchildren to determine the mean number of erupted permanent teeth and permanent first molars according to fluoride level in drinking water. The analysis included 13,348 children aged 5-17 years with a history of single residence. We also estimated the attack rate (decayed, missing, and filled surfaces/surfaces at risk) for fluoride deficient, suboptimal, and optimally fluoridated areas adjusting for covariates. Multivariable statistical analyses were performed to control for potential confounders. By age 7, almost all permanent first molars had erupted. The adjusted mean number of erupted permanent first molars per child were 3.81, 3.67, and 3.92 in areas with <0.3, 0.3-<0.7, and 0.7-1.2 ppm of fluoride, respectively. The adjusted caries attack rate in the first permanent molars among 5- to 17-year-old children was 93, 81, and 78 per 1,000 surfaces in fluoride deficient, suboptimal, and optimally fluoridated areas, respectively (P < 0.0001). This pattern of higher first molar attack rate among children in the fluoride-deficient communities was also observed in all erupted teeth. Exposure to fluoride in drinking water did not delay the eruption of permanent teeth. The observed difference in dental caries experience among children exposed to different fluoride levels could not be explained by the timing of eruption of permanent teeth.

Fluoride Concentration in Dentin of Exfoliated Primary Teeth as a Biomarker for Cumulative Fluoride Exposure

A biomarker for lifetime fluoride exposure would facilitate population-based research and policy making but currently does not exist. This study examined the suitability of primary tooth dentin as a biomarker by comparing dentin fluoride concentration and fluoride exposures. Ninety-nine children’s exfoliated primary teeth were collected from 2 fluoridated and 2 fluoride-deficient communities in North Carolina. Coronal dentin was isolated by microdissection and fluoride concentration assayed using the microdiffusion, ion-specific electrode technique. Information on children’s fluoride exposures since birth from drinking water, toothpaste, supplements, rinses, food and beverages was collected by a self-reported questionnaire administered to caregivers. Only a small portion of the variance (10%) in incisor dentin fluoride (mean 792, SD 402 mg/kg) was accounted for by the best linear regression model as evaluated by the adjusted R². A moderate portion of the variance (60%) of molar dentin fluoride (mean 768, SD 489 mg/kg) was predicted by dietary fluoride supplement exposures, community of residence, and frequent tea consumption. Results for molars suggest that primary tooth dentin concentration may prove to be a satisfactory biomarker for fluoride exposure.

A prevalence study of dental fluorosis in infancy

Objectives To determine the prevalence and severity of fluorosis in permanent incisor teeth in young children in a fluoridated and a fluoride-deficient community and to establish what relationship, if any, there was between the occurrence of dental fluorosis and the reported use of fluoride toothpaste in childhood. Design A prevalence study of children aged 8–9 years who had been continuous residents in fluoridated Newcastle or fluoride-deficient Northumberland. Method The permanent maxillary central incisor teeth were examined clinically and photographically by one examiner using the Thylstrup-Fejerskov index; the photographs were read blind to child identity and clinical score. A closed-response questionnaire enquired into the child's early experiences of toothbrushing and use of fluoride toothpastes. Social deprivation was measured by a Jarman score. The study took place in 1998. Outcome measure Prevalence of dental fluorosis measured by the Thylstrup– Fejerskov index. Results Complete data were available for 78% (n = 409) and 79% (n = 403) of eligible sampled children in the two areas, respectively. Clinical and photographic results agreed closely and had high reproducibility. The prevalence of fluorosis was 54% in the fluoridated area and 23% in the fluoride-deficient area when all grades (> 0) of fluorosis were included; percentage prevalence of mild to moderate fluorosis (≥ 3) was 3% and 0.5% in the two areas, respectively. Multivariate analysis indicated that area of residence (odds ratio = 4.5), Jarman score (odds ratio = 0.99 per Jarman unit) and type of toothpaste (odds ratio = 1.6) were statistically significantly related to presence or absence of fluorosis: the risk factors were – fluoridated area, affluence, and use of adult toothpaste. Conclusions and recommendations The prevalence of aesthetically important dental fluorosis was low, although higher in the fluoridated area. Use of a child's toothpaste (with lower fluoride concentration) could decrease risk in a fluoridated area. Adherence to the guidelines published by the British Society of Paediatric Dentistry is recommended.

A half-century of community water fluoridation in the United States: review and commentary.

The nearly 50-year history of community water fluoridation is reviewed with the major emphasis on the benefits and safety of fluoridation. Other aspects of water fluoridation also described include the apparent reduction in measurable fluoridation benefits because of the abundance of other fluoride sources, the diffusion of fluoridation effects into fluoride-deficient communities, preeruptive and posteruptive effects, technical and cost aspects, sociopolitical and legal issues that affect the successful fluoridation of communities, and alternatives to community water fluoridation. The majority of studies have evaluated the effectiveness of water fluoridation on the permanent teeth of children, while there are fewer studies on deciduous teeth and in adults; the relationship between fluoride ingestion and bone health needs further clarification; the sociopolitical issues of fluoridation need to be better understood.

Caries Risk Assessment by a Cross-sectional Discrimination Model

Although the prevalence of dental caries is continuing to decline, it still affects a majority of the US population and can be a serious problem for those afflicted. The objective of this project was to develop and perfect a model for assessment of risk of dental caries onset in children. In the first study, reported herein, a set of clinical, microbiological, biochemical, and socio-demographic variables was identified that distinguished, with an acceptable level of sensitivity and specificity, between children who had no previous caries experience and children who had high caries levels. A total of 313 children--age 12-15 years, 140 from a fluoridated community and 173 from a fluoride-deficient community--was selected on the basis of previous caries experience, either zero DMFS or high DMFS (> or = 6 in the fluoridated or > or = 8 in the fluoride-deficient community). Clinical exams for DMFS, dental fluorosis, and plaque were conducted. Stimulated whole saliva was collected for analysis of mutans streptococci, lactobacilli, total viable flora, and fluoride concentration. A questionnaire was used for collection of demographic data as well as information on prior fluoride exposure, dietary habits, and oral hygiene practices. By means of discriminant analyses, with use of seven key clinical and laboratory variables, it was possible for zero-DMFS subjects to e classified correctly (specificity) in 77.6% of cases in the fluoridated community and in 86.1% of cases in the fluoride-deficient community. High-caries subjects were classified as such (sensitivity) in 79.3% and 88.1% of cases, respectively.

Fluoride content of school lunches from an optimally fluoridated and a fluoride-deficient community

This study was conducted to compare contemporary dietary fluoride intake to surveys conducted a decade ago. It also served as a means of evaluating the difference in fluoride intake between residents of an optimally fluoridated and a fluoride-deficient community. Forty-four type A school lunches were collected from an optimally fluoridated ( n = 24) and a fluoride-deficient ( n = 20) community and analyzed for fluoride content. Fluoride analysis was accomplished using a microdiffusion technique to assay the acid-diffusible fluoride fractions. The mean total fluoride content of the lunches from the optimally fluoridated community was 227 μg. This was significantly higher than the mean fluoride content of 54 μg from the lunches in the fluoride-deficient community. The mean fluoride concentrations of the solid food from the optimally fluoridated and the fluoride-deficient communities were 0.53 and 0.23 μg fluoride/g, respectively. This difference was also statistically significant. The differences between the two communities in fluoride content of the lunches may be due to differences in the processing and cooking of the samples, primarily in the use of optimally fluoridated water for preparing some foods. In addition, the fluoride content of the lunches from the optimally fluoridated community was higher than expected on the basis of previous reports from similar communities. This difference may be related to differences in analytical techniques, changes in dietary habits, and an increase of fluoride in the food chain.

Associations of microbiological factors and plaque index with caries prevalence and water fluoridation status

Plaque indices, numbers of mutans streptococci, lactobacilli and total viable flora in plaque and saliva were assessed as part of a large-scale cross-sectional study designed to determine the factors that are associated with high caries activity in children. Subjects, 12 to 15 years old, residing in areas where the water supplies were either fluoridated (n = 140) or fluoride-deficient (n = 173) were studied. Mutans streptococci and lactobacilli numbers in saliva were positively correlated with plaque index. Plaque indices were significantly higher in the high-caries group than in the zero-caries group of the fluoride-deficient community. In the fluoridated community, there was no difference in the plaque index between the zero- or high-caries groups. In each community, pooled dental plaque and saliva harbored fewer mutans streptococci and lactobacilli in the zero-caries than the high-caries group. Greater numbers of mutans streptococci were found in the dental plaque and saliva of the zero-caries subjects in the fluoridated community than in the fluoride-deficient community, suggesting that a greater caries challenge can coexist with zero-caries status in the fluoridated community.

A Critique of Topical Fluoride Methods (Dentifrices, Mouthrinses, Operator‐, and Self‐applied Gels) in an Era of Decreased Caries and Increased Fluorosis Prevalence

Within the last 20 years there has been a decrease in the caries prevalence of US schoolchildren, a change in the intraoral caries pattern, and a slowing of the progress of lesions. Simultaneously, the prevalence of enamel milder, cosmetically acceptable forms and is more noticeable in fluoride-deficient communities than those with optimal or above-optimal water fluoride concentrations. Circumstantial evidence indicates that a principal contributor to the caries decline is the extensive use of fluoride dentifrices. Conversely, although use of a fluoride dentifrice can add to the total daily amount of ingested fluoride in preschool children, there is little evidence to suggest that dentifrice ingestion is a principal factor causing the fluorosis increase. The value of fluoride methods may be assessed in relative or absolute terms. The relative, or percentage, caries reduction attributed to fluoride mouthrinses and gels appears to be a property intrinsic to the methods themselves and generally is little affected by the caries activity of the population being treated. Conversely, the absolute, or numerical, caries reduction is dependent upon the level of disease in the population. Thus, the reported caries decline reduces the number of surfaces prevented from developing caries, even though the percentage reduction remains substantially unchanged. Although inadvertent ingestion of fluoride can result from the use of mouthrinses and gels, there is little evidence to suggest that they have contributed to the fluorosis increase. When using topical methods, prudence should prevail to avoid ingestion of fluoride. Fluoride dentifrices should continue to be used routinely, and although lower potency dentifrices may be considered, the literature does not provide strong support for their need. Use of fluoride mouthrinses and gels for individual patients should be predicted upon their caries activity or risk. Use of these methods in public health programs is a matter of cost-effectiveness, which will be influenced by the caries prevalence of the target population.

The effectiveness of pit and fissure sealants.

This review addresses two major issues related to the use of pit and fissure sealants. First, the epidemiology of occlusal caries for children and adults is examined to determine if there is a basis for administering sealant programs to different age groups. Second, the effectiveness of pit and fissure sealants in fluoridated and non-fluoridated communities is compared. Changes in effectiveness of sealant over time are evaluated in terms of percent effectiveness, complete retention, caries incidence, and reapplication rates. Based on epidemiologic evidence, sealant programs can be justified for children and young adults, but not for older age groups. Based on the literature reviewed, following one application of autopolymerized or visible-light-cured sealant, the median percent effectiveness declines from 83 percent after one year to 55 percent after seven years. Similarly, the median complete retention declines from 92 percent after one year to 66 percent after seven years. Conversely, the median percent of sealed first molars becoming carious and/or restored increases from 4 percent after one year to 31 percent after seven years. Large differences in sealant effectiveness are not apparent between studies performed in fluoridated and fluoride-deficient communities.

Review of the anticaries effectiveness of professionally applied and self-applied topical fluoride gels.

Of the five types of topical fluoride gel products available in the United States, two have not been clinically tested in randomized double blind clinical trials. For those tested, the averaged results of clinical trials involving schoolchildren in fluoride-deficient communities indicate a caries reduction of approximately 26 percent from either a professional or self-administered program. A similar relative reduction can be expected from programs conducted in fluoridated communities, but the absolute caries inhibition is less. Twice-a-year professional applications are more effective than once-a-year applications, and self-applications using trays are more effective than applying the gel on a toothbrush. For subjects beyond school age, there are few clinical studies of either self-applied or professionally applied gels; however, current epidemiological evidence does not indicate a need for public health caries preventive programs for healthy employed adults. For medically compromised patients, especially those exhibiting rampant caries associated with radiation-induced xerostomia, a variety of topical gel procedures appear to be effective in limiting caries.

Fluoridation referendum in La Crosse, Wisconsin: contributing factors to success.

Residents of La Crosse, Wisconsin approved a public referendum in favor of water fluoridation on April 5, 1988. The vote, 57 percent supportive, culminated a two-year community effort. Three public referenda had been defeated in the past. Contributing to the success of this recent campaign were: broad-based community support led by a 34-member Citizens for Better Dental Health in La Crosse Committee; American Dental Association/Wisconsin Division of Health/US Public Health Service consultation and support; knowledgeable and supportive press coverage; the timing of the ballot to coincide with the Wisconsin Presidential Primary; and local chiropractic support to offset chiropractic anti-fluoridation leadership. La Crosse, population 50,000, was the largest fluoride-deficient community in a nine-state upper Midwest area.

Three-year root caries increments: an analysis of teeth and surfaces at risk.

Seven hundred and ninety-six adult subjects (mean age 39.9 years) received visual-tactile examinations for root caries over a three-year period. All subjects were employed or the spouses of employees and resided in fluoride-deficient communities on Long Island, New York. Incremental caries data were analyzed to provide descriptive information about the susceptibility of individual teeth and surfaces to root caries. Molars were most prone to root caries/fillings, followed in decreasing order by premolars, canines and incisors. While canines and incisors had a nearly identical increment, since there are half as many canines as incisors in a mouth, canines are actually twice as susceptible to root caries/fillings. Facial surfaces comprised 53 percent of the increment followed by distal, lingual and mesial surfaces. Approximately 70 percent of the DFS for facial and lingual surfaces were fillings, compared to approximately 50 percent for mesial and distal surfaces, suggesting that part of the increment for facial-lingual surfaces may be treated abrasion areas rather than caries.

Primary canine hypoplasia in Head Start children.

Primary canine hypoplasia is an incomplete or defective development of the enamel matrix. The lesion is located on the labial surface and is seen more frequently on mandibular teeth. The purpose of this preliminary study was to determine the prevalence of this lesion among Head Start children. During a dental needs assessment of Mississippi Head Start children, 371 children from 11 centers were examined for this lesion. Of the centers, four were located in optimally fluoridated communities, and six were located in fluoride-deficient communities. Ages ranged from three to five years. There were 206 males and 165 females, 334 black and 37 white children. At ten centers all children were black, while all children at one center were white. Results indicated no significant differences in the black population between fluoridated (38.2%) and fluoride-deficient (36.3%) communities (P = .729) or between males (36.8%) and females (37.6%) (P = .877). When data were collapsed on sex and fluoridation status, the racial differences were highly significant (P = .001). The prevalence rate of dental caries associated with primary canine hypoplasia was 26.0 percent. These preliminary data indicate that the presence of primary canine hypoplasia may result in an increased potential for the tooth becoming carious.

Effect of a 0.05% neutral NaF mouthrinse on coronal and root caries of adults.

Three‐year coronal and root caries increments were compared in adults rinsing with either a 0.05% neutral NaF mouthrinse or a placebo mouthrinse. 1006 subjects, initially 20–65 years old (mean age: 39.9 yrs). who resided in fluoride deficient communities used a fluoride or placebo mouthrinse daily in their homes and brushed with an A.D.A. accepted fluoride dentifrice provided by the study. After three years, 731 subjects remained. Compliance was good. There were no significant differences (t‐test, p≤ 0.05) in coronal DMFT, coronal DMFS, root DFT and root DFS between the two groups. In subjects exhibiting root caries at the final examination, the DF root surface increment was 25.1% less in the fluoride mouthrinse users compared to those using the placebo rinse, but this difference was not statistically significant. The only significant difference in the caries increment between the two study groups was found for the mesio‐distal root surfaces of 45–65 year old participants.

Two years' effect on the primary dentition of mouthrinsing with a 0.2% neutral NaF solution

The benefits to the primary teeth from a school-based fluoride mouthrinsing program are presented. Children in grades 1--4, residents of a fluoride-deficient community in New York, rinsed an average of 49 times during 2 school years using a 0.2% neutral NaF solution. Rinsing was done under the supervision of homeroom teachers. Differences in caries prevalence of 20.0% (dfs/child) or 23.8% (dfs/100s) were found in children who participated in the rinsing program for 2 years compared with baseline caries scores of children who never rinsed. Surface specific differences in caries prevalence after 2 years were: 27.5% for proximal surfaces, 24.1% for buccolingual surfaces, and 12.4% for occlusal surfaces.

Comparisons of caries prevalence of children with different daily toothbrushing frequencies

Clinical caries examinations, supplemented by bite-wing radiographs, were conducted on 290 schoolchildren. The children ranged from 12 to 15 years of age and were residents of a fluoride-deficient community in New York State. The children were divided into two groups based upon their stated daily toothbrushing frequency, namely, those brushing once or less/day and those brushing twice or more/day. Mean DMFS and DMFT scores were recorded for children in both categories. A trend was noted that more frequent brushing was associated with less caries activity. For females and male-females combined the differences in mean DMFS and DMFT scores between those children brushing once a day or less. The caries scores for males in these two brushing groups were marginally significant (P less than .05). Ninety percent of the children used fluoride-containing dentifrices. The inverse relationship between brushing frequency and caries activity may be related to the more frequent fluoride contact when the children brush.

Self-application of fluoride as a community preventive measure: rationale, procedures, and three-year results

Results after three years of two clinical trials in which a fluoride self-application treatment program was administered to schoolchildren confirm the caries-reducing benefits of the program. The rationale and procedures for conducting the program are given. The semiannual supervised self-application of a prophylactic paste, containing 9% stannous fluoride, in school programs, resulted in a statistically significant protective effect against the development of caries. The rationale and detailed procedures for implementing and conducting self-application treatment programs with a stannous fluoride paste are presented. The results observed with the semiannual use of this treatment procedure for a three-year period in children 6 to 14 years of age who were lifetime residents of an optimal fluoride area indicated a significant reduction in the incidence of dental caries of 30.1% and 24.7% as expressed by DMF teeth and surfaces, respectively. If only the teeth that erupted during the study period were considered, the magnitude of the protective effect was 38.4%. The findings in a similarly designed study involving children living in a fluoride-deficient community indicated that the treatments resulted in significant reductions in DMF teeth and surfaces of 31.6% and 37.4%, respectively. In this instance, 37.0% fewer lesions were observed in the teeth that erupted during the study. These findings indicate that this procedure should be considered in public health programs as a means of contributing to the control of dental caries.

Prophylaxis of dentalcaries: Relative effectiveness of chewable fluoride preparations with and without added vitamins

Summary A clinical study was conducted which included815 children between 18 and 39 months of age residing in three different fluoride-deficient communities. The children received chewable tablets containing vitamins, vitamins plus fluoride, or fluoride alone and were examined for dental caries initially and at 6 month intervals. The findings during the first two years of the 5 year study indicate that a significant reduction in the incidence of dental caries of about 37 per cent was observed after six months in the children ingesting either the fluoride or vitamin-fluoride supplements. This degree of protection increased to about 55 and 63 per cent, respectively, after the children had used the supplement for one and two years. No differences in efficacy were observed between the fluoride and vitamin-fluoride preparations. No toxicity related to the use of fluoride was encountered.

The Newburgh-Kingston caries fluorine study IV. Dental findings after six years of water fluoridation

It is the prevailing scientific opinion, as expressed by leading health organizations ∗ ∗ American Dental Association, American Public Health Association, American Medical Association, American Association of Public Health Dentists, State and Territorial Health Officers Association, United States Public Health Service, National Research Council, and The American Waterworks Association. in this country, that the fluoridation of potable water to a concentration of 1 p.p.m. F. is a safe, beneficial, and practical public health procedure. This is based on: (1) a critical review of the available literature on fluoride compounds and the effects of ingested fluorides on both man and animal; (2) on the data obtained from the carefully controlled studies such as the Newburgh-Kingston, Grand Rapids-Muskegon, and the Evanston studies; (3) on the vital statistics from naturally fluoridated areas in which considerable numbers of persons have lived for generations as compared with the vital statistics from fluoride-free areas. Many fluoride-deficient communities throughout the United States have already initiated programs to correct this deficiency. As of Sept. 15, 1952, according to a current report 8 from the United States Public Health Service, 427 communities serving a population of 8 1 2 million persons are now practicing water fluoridation. In addition, 299 communities serving 15,360,000 persons have approved this new public health procedure and should have fluoridation programs in operation shortly. Dentistry has added a new milestone in public health. With the expansion of water fluoridation programs it may be expected that dental caries will lose its dubious honor of being the most prevalent disease to which mankind is subject.