published_or_final_version / Dentistry / Master / Master of Philosophy

published_or_final_version / Paediatric Dentistry / Master / Master of Dental Surgery

A importância da fluoretação da água de abastecimento público na prevenção da cárie dentária é reconhecida e exaustivamente estudada desde 1945. O objetivo desta pesquisa foi o de avaliar a concentração de flúor presente na água de abastecimento público de Bauru, SP, antes e depois do processo de fluoretação. Para tanto estabeleceu-se um protocolo para a coleta de amostras de água durante três dias de uma semana, a cada três meses, durante as quatro estações do ano. As amostras foram coletas na ETA e nos 27 poços que abastecem a cidade, antes e depois da fluoretação, e em 63 pontos (residências) estabelecidos a partir do mapa onde estão definidos os 19 setores de abastecimento, com a finalidade de coletar amostras em toda a extensão da rede. A análise das amostras foi realizada em duplicata, utilizando-se o eletrodo íon-sensível (Orion 9609), acoplado ao potenciômetro (Procyon, modelo 720), adicionando 1 mL de TISAB II a 1 mL da amostra. A checagem dos resultados da análise das amostras de água foi feita através de nova leitura de 10% das amostras e com uma reprodutibilidade mínima estabelecida em 90%. Não foram observadas variações na concentração do flúor naturalmente presente na água em função da sazonalidade de cada uma das estações do ano. A concentração, das 318 amostras analisadas, variou entre 0,05 e 0,15 mg F/L. Entretanto, a média das concentrações de flúor verificadas nas 297 amostras obtidas na ETA e nos poços após a fluoretação variou entre 0,26 e 6,23 mg F/L e das 697 amostras das residências, entre 0,10 e 0,91 mg F/L. A concentração de flúor presente na água de abastecimento público de Bauru, antes da fluoretação, mostrou-se constante, diferente daquela verificada após a fluoretação, que apresentou grandes oscilações na sua concentração de flúor, indicando que o sistema de abastecimento de Bauru não mantém constantes os níveis de flúor na água. / The importance of public water fluoridation for the prevention of dental caries has been scientifically recognized. The aim of this study was to evaluate the fluoride concentration of the public water supply of Bauru, SP, before and after the fluoridation, in different seasons. It was established a protocol for collecting water samples during 3 days in a week, every 3 months. Samples were collected at the Water Treatment Station and in 27 wells that supply the city, before and after fluoridation. In addition, samples were also collected in 63 points (houses), which were selected from a city map, corresponding to the 19 sections of supply, in order to represent all the distribution system. Samples were analyzed in duplicates, using an ion-sensitive electrode (Orion 9609), coupled to a potentiometer (Procyon, model SA 720), by adding 1 mL of TISAB to 1 mL of the water sample. Repeatability was checked in 10% of the samples and was higher than 90%. No differences in the natural fluoride concentration in water were observed in the four different seasons. However mean fluoride concentrations found in the 297 samples collected in the Water Treatment Station and in the wells after fluoridation varied between 0.26 and 6.23 mg F/L. For the 697 samples collected in the houses, the ranged was from 0.10 to 0.91 mg F/L. Natural fluoride concentration in the water before fluoridation was constant, differently from fluoride concentration in the public water supply after fluoridation, which spanned a wide range. This indicates that the system of supply of Bauru does not maintain constant water fluoride levels.

No Brasil existem dificuldades para o controle da dosagem correta do flúor na água de abastecimento, ainda que sua incorporação represente um método seguro, econômico, eficaz e eficiente para reduzir os níveis de cárie dentária na população. O flúor presente constantemente na água ingerida participa dos ciclos de desmineralização e remineralização do esmalte dentário, atuando de forma terapêutica e preventiva, tendo sido atribuída à fluoretação das águas uma redução de 30 a 60% na incidência da cárie dentária. Para alcançar os efeitos preventivos, os teores adequados precisam ser mantidos permanentemente, pois a interrupção temporária ou definitiva e teores de flúor abaixo do recomendado acarretam a perda do benefício pela população. Para teores acima do recomendado, corremos o risco de desenvolver a fluorose dentária nas crianças cujos dentes estejam em formação. Este estudo propõe, através de uma metodologia qualitativa, usando como estratégia investigativa a entrevista semi-estruturada e a análise documental, conhecer como o município de Ribeirão Preto realiza o monitoramento da fluoretação das águas de abastecimento público, contextualizando-o com as políticas públicas de saúde, sendo no campo da saúde bucal, seu principal avanço foi a redução do índice CPO-D, de 6,14 em 1992, para 1,95 em 2004. Contudo, o município ainda apresenta dificuldades para universalização da assistência odontológica e para as referências de especialidades. A rede de abastecimento público de água do município apresenta uma singularidade ao ser constituída por 99 poços artesianos, que constituem 76 pontos para aplicação do cloro e flúor, sendo que este último começou a ser adicionado a partir de 1987, somente atingindo 100% dos poços em 1996.Inúmeras dificuldades de ordem técnica, de recursos materiais, humanos, administrativos e financeiros precisam ser superados para que a fluoretação efetivamente aconteça e somente a partir de 1997 o heterocontrole passou a ser realizado. A partir de 2000 a Vigilância Sanitária passou a realizar o acompanhamento da fluoretação e dentre as amostras analisadas, menos de 50% estão com teor adequado para o flúor, geralmente abaixo de 0,6 ppm, com prejuízos dos benefícios previstos por essa ação. As ações e projetos para melhorias na fluoretação ainda não foram capazes de melhorar esses resultados. A participação e o controle social da fluoretação representam ainda um processo incipiente na construção das políticas públicas vigentes no Município. / In Brazil there are several problems to control de correct level of fluoride in the public water system, although its incorporation is a safe, economic, efficacious and efficient method to reduce tooth cavities in the population. The fluoride ingested regularly in the water influences the demineralization and remineralization cycles and is a therapeutic and preventive strategy. Some studies found that water fluoride contributes to a 30 to 60% reduction of dental cavities incidence. In order to achieve preventive effects, the adequate levels of fluoride must be continuously maintained as its temporary or definitive interruption and low fluoride doses (below the recommendation) can result in the loss of its benefits. On the other hand, high fluoride doses cause the risk of dental fluorosis especially in children whose teeth are still developing. Based on a qualitative methodology and using semi-structured interviews and analysis of documents, the author aimed at learning how the municipality of Ribeirão Preto monitors the public water fluoride levels, in the context of public health policies. The main improvement in oral health was the reduction of CPO-D index, from 6.14 in 1992 to 1.95 in 2004, although it still presents difficulties regarding care universalization and speciality references. The public water system has 99 artesian wells with 76 places for chloride and fluoride application. Fluoride application began in 1987, achieving 100% in 1996. Several technical problems or regarding material, human, administrative and financial resources are observed and must be solved in order to have effective water fluoridation. Only in 1997, the municipality initiated the fluoride control. In 2000, the Sanitary Surveillance Department began to supervise water fluoridation and among the analyzed samples, less than 50% present the adequate level of fluoride, generally below 0.6 ppm, impairing possible benefits. The actions and projects directed to improve the fluoride levels did not achieve good results. Social participation and control of fluoridation still represent an incipient process in the construction of public policies in the municipality.

The use of fluoride involves a balance between the protective effect against caries and the risk of having fluorosis. Fluorosis in Australian children was highly prevalent in the early 1990s. Policy initiatives were introduced to control fluoride exposure so as to reduce the prevalence of fluorosis. Objective: The study aimed of describing the prevalence, severity and risk factors for fluorosis, and to escribe the trend of fluorosis among South Australian children. The study also aimed of exploring the effect of the change in fluoride exposure on dental fluorosis and caries. Methods This research project was nested in a larger population-based study, the Child Oral Health Study (COHS) in Australia 2002-2005. The parent study's sample was chosen using a multistage, stratified random selection with probability of selection proportional to population size. Fluoride exposure history was retrospectively collected by a parental questionnaire. This nested study sample (n=1401) was selected from the pool of South Australian (SA) COHS participants. Children were selected by year of birth to form three birth cohorts: those born in 1989/90; 1991/92; and 1993/94. Children were approached in two further stages: a dental health perception questionnaire, and a clinical examination for fluorosis. Some 898 children took part in the first stage. Among those, one trained dentist examined 677 children for fluorosis under clinic conditions using two indices (the Fluorosis Risk Index (Pendrys, 1990) and the TF Index (Thylstrup and Fejerskov, 1978)). The Dental Aesthetic Index score (DAI) was also recorded. Caries experience extracted from dental records of all previous visits to school dental linics was used to enable calculation of dmfs/DMFS scores at different anchor ages. Data were re-weighted age and sex to represent the South Australian child population. Per cent lifetime exposure to fluoride in water and patterns of discretionary fluoride use were calculated. Fluorosis data were used to calculate the prevalence and severity of fluorosis. Caries dmfs/DMFS scores were calculated at different anchor ages to enable comparison between birth cohorts. Results A higher proportion of children in the later birth cohorts used low concentration fluoride toothpaste, and a smaller amount of toothpaste was used when they commenced toothbrushing. There was a significant decline in the prevalence of fluorosis across the three successive birth cohorts. Risk factors for fluorosis, defined by the two indices, were use of standard fluoride toothpaste, an eating and/or licking toothpaste habit, and exposure to fluoridated water. Means (SD) of the deciduous caries dmfs scores at age six and eight were 1.45 (3.11) and 2.46 (3.93) respectively. Evaluation of the "trade-off" between fluorosis and caries with fluoride exposure indicated that the use of low concentration fluoride toothpaste and preventing an eating/licking of toothpaste habit could reduce the prevalence of fluorosis without a significant increase in caries experience. Conclusion There was a marked decline in the prevalence of fluorosis across the three successive birth cohorts. The decline was linked with the reduction in exposure to fluoride. Exposure to fluoridated water and several components of toothpaste use were risk factors for fluorosis. Establishing an appropriate use of fluoride toothpaste could be successful in reducing fluorosis without a significant increase in caries experience. / Thesis (Ph.D.)--Dental School, 2004.

Consistent evidence confirms that the addition of fluoride to achieve an optimal concentration in potable water supplies is both safe and effective in reducing community caries experience. While public acceptance and use of water fluoridation in Australia has been high for forty years, its implementation in Queensland remained low until December 2008. Political and social scientists have long recognised that the formation and maintenance of public policy in Australia is a complex interactive process involving inter alia government, bureaucracy, pressure groups and voters. However, explanations of the factors influencing the outcome of a proposal to fluoridate a municipal water supply remain inadequate. The long evolution of adjusted fluoridation has its genesis in pre-1930 North American concerns over the disfigurement associated with endemic dental mottling. Throughout the 1930s and 1940s, many perceived this affliction as the visible manifestation of a public health problem: chronic fluoride intoxication. Reports of environmental contamination of the food chain from naturally over-fluoridated water and agrarian and industrial practices only increased community doubts about the accumulative and toxic potential of fluoride. For these and other reasons the public perception of fluoride was poor. Between 1937 and 1945, USPHS dental researcher and later Director of the National Institute of Dental Research HT Dean and co-workers emerged as the few who understood the fine line between fluoride therapy and toxicity. Their investigations involved not only specialised interpretations of human dental epidemiology but also multidisciplinary studies of human and animal fluoride exposure and homeostasis. However, decisions to implement water fluoridation had to come from the relevant government authorities. Here scientific knowledge faced political reality. Apart from perceived safety issues and resistance to the compulsory nature of water fluoridation, many other barriers to water fluoridation emerged: incompletely understood pharmacodynamics of fluoride; confounding issues in the initiation and propagation of caries; community acceptance of this epidemic; and political sensitivities regarding water. This scientific and social background explained why adjusted fluoridation was amenable to both challenge and misrepresentation. In the US, the constitutional, institutional and financial network provided the basis for an enduring culture of dental research that eventually provided the multidisciplinary evidence to endorse the safety and efficacy of water fluoridation. Although Australians did not experience a widespread human mottling problem akin to that in the United States, Australian fluoride advocates faced similar opposition. The Australian constitution, state parochialism and decentralisation compounded by vast distances fragmented the responsibilities for research, health and water treatment. Each state had limited resources and faced these responsibilities in its own way. Although there were several early attempts in some states at regional dental field studies, meaningful national dental epidemiology did not emerge until 1993. Hence, much of the supportive evidence for fluoridation in Australia had to be imported from North America. This background meant that wherever fluoridation was widely implemented in Australia, state authority played a role. In addition to the general social and scientific concerns about fluoride and fluoridation, before 1957 there were a number of unresolved scientific factors relating to naturally over-fluoridated ground water, climate, tea consumption and fluid homeostasis involving canecutters. These made Queensland different in the Australian context. After 1957, as these scientific concerns in Queensland diminished, the political landscape changed and provided new foundations for political hesitance and expedience. The timing and circumstances of the promulgation of the Fluoridation of Public Water Supplies Act (1963) influenced its nature to the extent that until 2008, this legislation with its link to various local government acts was unique within Australia. Although there were notable exceptions such as the decisions to fluoridate water supplies at Townsville and Mareeba, this legislative background established the “Queensland difference” as a fixture in fluoride debates across the state. When combined with inadequate state funding and a lack of political resolve from parliamentarians and councillors, prospects for fluoridation in Queensland were virtually paralysed. Nonetheless, while inquiry into the political reasons for the implementing or the failure to implement fluoridation remains thin, developments in Queensland after December 2007 lend significant weight to the finding that a politically resolute centralised authority with the responsibility for both health and water are key components in the outcome.

The use of fluoride involves a balance between the protective effect against caries and the risk of having fluorosis. Fluorosis in Australian children was highly prevalent in the early 1990s. Policy initiatives were introduced to control fluoride exposure so as to reduce the prevalence of fluorosis. Objective: The study aimed of describing the prevalence, severity and risk factors for fluorosis, and to escribe the trend of fluorosis among South Australian children. The study also aimed of exploring the effect of the change in fluoride exposure on dental fluorosis and caries. Methods This research project was nested in a larger population-based study, the Child Oral Health Study (COHS) in Australia 2002-2005. The parent study's sample was chosen using a multistage, stratified random selection with probability of selection proportional to population size. Fluoride exposure history was retrospectively collected by a parental questionnaire. This nested study sample (n=1401) was selected from the pool of South Australian (SA) COHS participants. Children were selected by year of birth to form three birth cohorts: those born in 1989/90; 1991/92; and 1993/94. Children were approached in two further stages: a dental health perception questionnaire, and a clinical examination for fluorosis. Some 898 children took part in the first stage. Among those, one trained dentist examined 677 children for fluorosis under clinic conditions using two indices (the Fluorosis Risk Index (Pendrys, 1990) and the TF Index (Thylstrup and Fejerskov, 1978)). The Dental Aesthetic Index score (DAI) was also recorded. Caries experience extracted from dental records of all previous visits to school dental linics was used to enable calculation of dmfs/DMFS scores at different anchor ages. Data were re-weighted age and sex to represent the South Australian child population. Per cent lifetime exposure to fluoride in water and patterns of discretionary fluoride use were calculated. Fluorosis data were used to calculate the prevalence and severity of fluorosis. Caries dmfs/DMFS scores were calculated at different anchor ages to enable comparison between birth cohorts. Results A higher proportion of children in the later birth cohorts used low concentration fluoride toothpaste, and a smaller amount of toothpaste was used when they commenced toothbrushing. There was a significant decline in the prevalence of fluorosis across the three successive birth cohorts. Risk factors for fluorosis, defined by the two indices, were use of standard fluoride toothpaste, an eating and/or licking toothpaste habit, and exposure to fluoridated water. Means (SD) of the deciduous caries dmfs scores at age six and eight were 1.45 (3.11) and 2.46 (3.93) respectively. Evaluation of the "trade-off" between fluorosis and caries with fluoride exposure indicated that the use of low concentration fluoride toothpaste and preventing an eating/licking of toothpaste habit could reduce the prevalence of fluorosis without a significant increase in caries experience. Conclusion There was a marked decline in the prevalence of fluorosis across the three successive birth cohorts. The decline was linked with the reduction in exposure to fluoride. Exposure to fluoridated water and several components of toothpaste use were risk factors for fluorosis. Establishing an appropriate use of fluoride toothpaste could be successful in reducing fluorosis without a significant increase in caries experience. / Thesis (Ph.D.)--Dental School, 2004.

Thesis (M.S.P.H.)--University of Michigan, 1942.

Thesis (M.S.P.H.)--University of Michigan, 1942.

Thesis (M.S.)--University of Michigan, 1996.