Exposure to water fluoridation and caries increment.
ABSTRACT The objective of this cohort study was to examine the association between exposure to water fluoridation and the increment of dental caries in two Australian states: Queensland (Qld)--5 per cent fluoridation coverage; and South Australia (SA)--70 per cent fluoridation coverage.
Stratified random samples were drawn from fluoridated Adelaide and the largely non-fluoridated rest-of-state in SA, and fluoridated Townsville and non-fluoridated Brisbane in Qld.
Children were enrolled between 1991 and 1992 (SA: 5-15 yrs old, n = 9,980; Qld: 5-12 yrs old, n = 10,695). Follow-up caries status data for 3 years (+/- 1/2 year) were available on 8,183 children in SA and 6,711 children in Qld.
Baseline data on lifetime exposure to fluoridated water, use of other fluorides and socio-economic status (SES) were collected by questionnaire, and tooth surface caries status by dental examinations in school dental service clinics.
Higher per cent lifetime exposure to fluoridated water (6 categories: 0;1-24; 25-49; 50-74; 75-99; 100 per cent) was a significant predictor (ANOVA, p < 0.01) of lower annualised Net Caries Increment (NCI) for the deciduous dentition in SA and Qld, but only for Qld in the permanent dentition. These associations persisted in multiple linear regression analyses controlling for age, gender, exposure to other fluorides and SES (p < 0.05).
Water fluoridation was effective in reducing caries increment, even in the presence of a dilution effect from other fluorides. The effect of fluoridated water consumption was strongest in the deciduous dentition and where diffusion of food and beverages from fluoridated to non-fluoridated areas was less likely.
Article: Bias in observational studies.American journal of orthodontics and dentofacial orthopedics: official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics 04/2014; 145(4):542-3. DOI:10.1016/j.ajodo.2014.01.008 · 1.33 Impact Factor
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ABSTRACT: To compare the prevalence and severity of diffuse opacities among subjects whose maxillary incisors developed during periods with different concentrations of fluoride in the Hong Kong public water supply. Standardized intra-oral photographs of random samples of 12-year-old children were collected in 1983, 1991, 2001 and 2010 (n = 2658) in Hong Kong and were assessed for diffuse opacities by a calibrated and blinded examiner. The fluoride concentrations in the public water supply at the times when the enamel on their maxillary incisors developed were 1.0, 0.7, 0.5 and 0.5 ppm, respectively. The mouth prevalence figures for diffuse opacities of these children (based on the maxillary incisors) were 89.3%, 48.5%, 32.4% and 42.1 in the years 1983, 1991, 2001 and 2010, respectively. Variation in the mouth and tooth prevalences of diffuse opacities was apparent among the four different year groups (P < 0.0001). Marked differences in severity of diffuse opacities, in terms of different subtypes and maximum extent of tooth affected, were also observed in association with the year of study (P < 0.001). The prevalence and severity of diffuse opacities among maxillary incisor teeth of Hong Kong children decreased from 1983 and then increased in 2010; however, this change did not fully correspond to the concentration of fluoride in the drinking water during the time of enamel development.Community Dentistry And Oral Epidemiology 07/2013; DOI:10.1111/cdoe.12064 · 1.80 Impact Factor
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ABSTRACT: PURPOSE: To assess the damage and the prevalence of caries and fluorosis in children and adolescents in the metropolitan area after 8 years of drinking water fluoridation and to compare them with the baseline study. METHODS: This was a prevalence study. The sample was selected using two-step probability sampling and stratified according to socioeconomic level. Subjects included 2,323 schoolchildren aged 6 to 8 years and 12 years living within the metropolitan region. The parents of all students provided consent and were previously included in the study. The subjects were clinically examined by calibrated dentists, who used World Health Organization (WHO) screening criteria and indicators to determine the presence of caries and dental fluorosis. RESULTS: No cavity damage was found in 23.68% of the children. The average dmft was 3.18 for children aged 6 to 8 years. The DMFT was 0.59 in children aged 6 to 8 years and 2.6 in children 12 years compared with the baseline study. These differences were statistically significant. There were also significant differences in the DMFT index for each socioeconomic status group. The average number of dams was higher among children of low socioeconomic status. Of the studied children, 14.3% of children had dental fluorosis. Fluorosis was very mild in 12.35% of the cases, mild in 1.98% and moderate in 0.26%. There were no cases of severe fluorosis (classified according to Dean's index). CONCLUSION: We conclude that after 8 years drinking water fluoridation in the metropolitan area, the number of children with no history of caries has increased by approximately 100%. The number of cases significantly affected by caries has also decreased significantly. The incidence of dental fluorosis has increased, but to milder degrees.12/2010; 26(2):109-115. DOI:10.1590/S1980-65232011000200003