Exposure to water fluoridation and caries increment

Australian Research Centre for Population Oral Health, School of Dentistry, The University of Adelaide, South Australia.
Community dental health (Impact Factor: 0.6). 03/2008; 25(1):12-22. DOI: 10.1922/CDH_2067Spencer11
Source: PubMed


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.

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    • "York also noted that studies in communities with higher baseline dmft/DMFT values, as well as the studies of longer duration, showed greater benefits. Meanwhile, research workers continue to add to this evidence base (Spencer et al, 2008) Striking a balance between reducing decay and preserving aesthetics Balancing the benefits of less caries with the risk of an increase in dental fluorosis has always been an important consideration in determining fluoridation policy. Trendley Dean and his colleagues in their pioneering studies in the 1930s and 40s suggested that, at a fluoride concentration in water of 1ppm, the reduction in caries was substantial while the increase in fluorosis was confined to the milder forms (Lennon, 2006). "
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    ABSTRACT: Tooth decay rates among children have been falling in most European countries since the mid-1970s, with the gap between the countries with the highest and lowest average levels narrowing. Widespread use of fluoride toothpaste, high levels of educational achievement in the Scandinavian countries, and public health approaches such as the use of fluoridated salt in Switzerland, France and Germany, have all contributed to this welcome improvement. Whilst average tooth decay rates are down, those averages mask stubbornly high decay rates in some communities and in some social groups. Many young children in the UK still suffer from severe dental caries (BASCD, 2007). No one in public health could reason- ably argue that dental caries in the UK is a battle already won. It is not. Even if we take the deceptively soothing average dmft scores (decayed, missing or filled teeth), we find a fivefold difference between the best and worst dental health. The average South Staffordshire five year old has 0.6 dmf teeth (the best dental health in England), while the average Blackburn five year old has 3.2 dmf teeth (the worst in England) (BASCD, 2007). The quandary for members of a Strategic Health Authority (SHA) or Primary Care Trust (PCT) with en- duringly high rates of caries is: do they persevere with ineffective strategies or do they consider alternatives that have been tried elsewhere and worked? Earlier this year, the Secretary of State for England Alan Johnson - no doubt basing his comments on advice from his Chief Dental Officer - called on SHAs and PCTs in areas with high dental health needs to consider water fluoridation. No one is suggesting that all water supplies should be fluoridated. We suggest that the total population served by fluoridation schemes should be increased from 10% to around 30%. New schemes could be expected to be most effective in areas with particularly high levels of tooth decay among children. Subject to technical feasi- bility and public consultation, such schemes in England might include Greater Manchester, some other areas in the North West, and the large conurbations of Yorkshire. In addition, there are pockets of high dental need in, for example, Southampton and Inner London.
    Community dental health 06/2008; 25(2):66-9. DOI:10.1922/CDH_2435Lennon04 · 0.60 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
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    ABSTRACT: There is substantial evidence that fluoride, through different applications and formulas, works to control caries development. The first observations of fluoride's effects on dental caries were linked to fluoride naturally present in the drinking water, and then from controlled water fluoridation programs. Other systemic methods to deliver fluoride were later suggested, including dietary fluoride supplements such as salt and milk. These systemic methods are now being questioned due to the fact that many studies have indicated that fluoride's action relies mainly on its post-eruptive effect from topical contact with the tooth structure. It is known that even the methods of delivering fluoride known as 'systemic' act mainly through a topical effect when they are in contact with the teeth. The effectiveness of water fluoridation in many geographic areas is lower than in previous eras due to the widespread use of other fluoride modalities. Nevertheless, this evidence should not be interpreted as an indication that systemic methods are no longer relevant ways to deliver fluoride on an individual basis or for collective health programs. Caution must be taken to avoid excess ingestion of fluoride when prescribing dietary fluoride supplements for children in order to minimize the risk of dental fluorosis, particularly if there are other relevant sources of fluoride intake - such as drinking water, salt or milk and/or dentifrice. Safe and effective doses of fluoride can be achieved when combining topical and systemic methods.
    Monographs in oral science 06/2011; 22:133-45. DOI:10.1159/000325161
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