CARIES INCREMENT AMONG SCHOOLCHILDREN EXPOSED TO DIFFERENT FLUORIDE CONCENTRATIONS IN WATER: A FIVE-YEAR RETROSPECTIVE COHORT STUDY Previous studies have indicated that the cessation of community water fluoridation (CWF) leads to an increase in caries prevalence among schoolchildren. However, little is known about the rate of caries progression among schoolchildren exposed to different concentrations of fluoride in water. Hence, this study aimed to compare the mean caries increment in permanent dentition among Malaysian schoolchildren with partial exposure (in Pahang) and full exposure (in Perak) to CWF and determine its associated factors. This was a five-year retrospective cohort study using an analysis of secondary data of school dental records among schoolchildren exposed to different fluoride concentrations in the water supply. Children in Perak were exposed to CWF throughout life while children in Pahang were exposed to CWF for the first five to six years of their lives before it was discontinued. The children were followed retrospectively from 2015 (initially aged eight years old) to 2019 (12 years old). Relevant data such as demographic characteristics, caries experience and exposure to other clinical preventive dental treatments were extracted and analysed using SPSS 21.0. Descriptive, independent t-test and negative binomial regression were used to examine the data. The sample consisted of 462 school dental records in both states. The prevalence of schoolchildren with DMFT scores of 2 and ≥ 3 increased by 10.4% and 13.9%, respectively, in Pahang from 2015 to 2019, compared to 4.8% and 0.9% in Perak. The mean (M) and standard deviation (SD) of caries increment at tooth and surface levels in permanent dentition among schoolchildren in Pahang (M = 0.83, SD = ±1.50 and M = 1.00, SD = ±2.10) was significantly greater (p < 0.001) compared to Perak (M = 0.18, SD = ±0.53 and M = 0.22, SD = ±0.66) over the same period. After controlling for confounders, partial exposure to CWF remained a strong predictor for mean caries increment over a five-year study period. This study showed greater mean caries increment in permanent dentition among schoolchildren in Pahang after CWF ceased. Hence, the findings from this study could be used to assist policy makers to support reimplementation and continuation of CWF in Malaysia.

Introduction: Water fluoridation (WF) was ceased in the state of Pahang, Malaysia, in July 2012. Any changes in fluoride exposure during childhood can influence the development of fluorosis. Thus, this study aimed to compare the prevalence of fluorosis between WF-ceased and WF-continued areas in Malaysia, and its associated factors among 7 and 12-year-old children. Methods: A cross-sectional study was conducted among children in WF-ceased and WF areas (n=1211). The 12-year-olds in WF-ceased areas were exposed to WF between 4.5 to 6.5 years before cessation, and it was hypothesised they would have similar fluorosis prevalence as their counterparts who lived in WF areas. The 7-year olds were born during the cessation period. Examination of fluorosis was performed by a calibrated dentist using Dean’s criteria and a parental questionnaire was utilised to collect information about demographics and exposure to fluoride. Results: Fluorosis prevalence (Dean’s≥2) was significantly lower among children in WF-ceased areas than WF areas (p< 0.001). Intra-area comparison indicated that the 12-year olds have higher prevalence of fluorosis than the 7-year-olds, except for anterior fluorosis scores among those in WF areas. The majority of fluorosis cases were very mild in both areas. Simple logistic regression indicated that duration of exposure to WF, age, mother’s income and education, age started toothbrushing with toothpaste, and frequency of toothbrushing were associated with fluorosis. Conclusions: Fluorosis prevalence decreased following water fluoridation cessation. The null hypothesis that 12-year-olds in both areas would have similar prevalence of fluorosis was rejected. Several factors were associated with fluorosis.

nformation regarding water fluoridation (WF) in Malaysia has been substantially documented, but is scattered in various government publications and may be lost to the stakeholders. This paper is a review of water fluoridation in Malaysia and its effect on oral health: a history of WF in Malaysia, the current policy, the evidence of its effectiveness, the challenges and the future directions. A search for relevant physical and electronic documents of WF in Malaysia resulted in the identification of 70 documents for review. WF was gazetted as national policy with an optimal fluoride level of 0.7 parts-per-million (ppm) in 1972, with a reduction of the level to 0.5 ppm in 2005. Evidence showed that WF effectively reduced population dental caries while fluorosis was not a prevalent public health concern. Strong collaboration between stakeholders and the extensive network of piped water supplies resulted in 80% of the population receiving WF in 2013. However, the coverage was reduced to 74.1% in 2018, largely due to the cessation of WF in Pahang. The key challenges in WF included a lack of funding, weak legislation, use of reverse osmosis water filtration system, difficulty to maintaining an optimal level of fluoride in the water, and lack of local data on the impact of WF cessation on oral health, and its cost-effectiveness. This review will provide dental health professionals with scientific evidence on WF and oral health in Malaysia and assist them in answering relevant questions about WF raised by the public.
Dental Caries ; Fluorosis, Dental ; Malaysia ; Review [Publication Type] ; Fluoridation