Decline in the prevalence of dental fluorosis among South Australian children

Background: The use of fluoride involves a balance between protection against dental caries and risk of dental fluorosis. Fluorosis in Australian children was highly prevalent in the early 1990s. Policy measures were introduced to control fluoride exposure so as to reduce the prevalence of fluorosis. Objective: To evaluate the effectiveness of policy measures in reducing the prevalence of fluorosis among Australian children. Methods: A random sample of South Australian children born in 1989-1994 was selected in 2002/2003, stratified by fluoridation status and urban/rural residence. Children were targeted to form three successive birth cohorts: those children born in 1989/1990, 1991/1992 and 1993/1994, respectively. Fluoride exposures were assessed by questionnaire. One dentist examined 677 children for fluorosis using the Thylstrup and Fejerskov (TF) Index. Data were reweighted to reflect the state's child population. Case definitions of fluorosis were: having a TF score of 1+ (TF1+) or a TF score of 2+ (TF2+) on one or both maxillary central incisors. Results: A higher proportion of children in the later birth cohorts used low-concentration fluoridated toothpaste, and a smaller amount of toothpaste was used when they commenced toothbrushing. The fluorosis experience in this population was mostly very mild to mild. There was a significant decline in the prevalence of fluorosis across the three successive birth cohorts. The prevalence of fluorosis by TF1+ case definition declined from 34.7% to 22.1% and by TF2+ case definition from 17.9% to 8.3%. Risk factors for fluorosis were use of standard-concentration fluoridated toothpaste, an eating and/or licking toothpaste habit and exposure to fluoridated water. Conclusion: The experience of fluorosis among the South Australian child population was mostly very mild to mild. There was a marked decline in the prevalence of fluorosis across the three successive birth cohorts. The decline was mainly linked with the reduction in exposure to fluoride from fluoridated toothpaste.