Chronic Fluoride Toxicity: Dental Fluorosis

Abstract

Dental fluorosis occurs as a result of excess fluoride ingestion during tooth formation. Enamel fluorosis and primary dentin fluorosis can only occur when teeth are forming, and therefore fluoride exposure (as it relates to dental fluorosis) occurs during childhood. In the permanent dentition, this would begin with the lower incisors, which complete mineralization at approximately 2–3 years of age, and end after mineralization of the third molars. The white opaque appearance of fluorosed enamel is caused by a hypomineralized enamel subsurface; with more severe dental fluorosis, pitting and a loss of the enamel surface occurs, leading to secondary staining (appearing as a brown color). Many of the changes caused by fluoride are related to cell/matrix/mineral interactions as the teeth are forming. At the early maturation stage, the relative quantity of amelogenin protein is increased in fluorosed enamel in a dose-related manner. This appears to result from a delay in the removal of amelogenins as the enamel matures. In vitro, when fluoride is incorporated into the mineral, more protein binds to the forming mineral, and protein removal by proteinases is delayed. This suggests that altered protein/mineral interactions are in part responsible for retention of amelogenins and the resultant hypomineralization that occurs in fluorosed enamel. Fluoride also appears to enhance mineral precipitation in forming teeth, resulting in hypermineralized bands of enamel, which are then followed by hypomineralized bands. Enhanced mineral precipitation with local increases in matrix acidity may affect maturation stage ameloblast modulation, potentially explaining the doserelated decrease in cycles of ameloblast modulation from ruffleended to smooth-ended cells that occur with fluoride exposure in rodents. Specific cellular effects of fluoride have been implicated, but more research is needed to determine which of these changes are relevant to the formation of fluorosed teeth. As further studies are done, we will better understand the mechanisms responsible for dental fluorosis.

Reflexões metodológicas sobre prevalência da fluorose dentária nos inquéritos de saúde bucal

“…Accordingly, cities with fluoridated water and regular control did not show a prevalence of fluorosis above 30%, even when other sources of fluoride are considered. 9 Taking into account that there is a degree of imprecision inherent to the index used, the occurrence of random or systematic error ispossible. 5 This imprecision may be due to characteristics particular to the index or linked to deficiencies in the training and instruction process.…”

Combined Esthetic Therapy of Severe Dental Fluorosis: A Case Report

“…Dental fluorosis is a developmental disturbance caused by excessive fluoride ingestion during tooth formation 1 . The strong relationship between fluoride concentration in drinking water and the prevalence and severity of dental fluorosis were showed by Dean et al 2,3 .…”

“…Restoratif teknikler ile karşılaştırıldığında, teknik daha minimal invaziv, daha az zaman gerektiren ve daha ucuz olabilir. Anahtar Kelimeler: Dental florozis, mikroabrazyon, ev tipi beyazlatma, rezin infiltrasyon responsible for the prevalence of dental fluorosis 1,4 . Even a small 'pea-sized 'amount of toothpaste containing 1450 ppm fluoride would provide approximately 0.36-0.72 mg fluoride, which if consumed twice a day could contribute to fluoride levels that would increase the risk of dental fluorosis in children 5 .…”

“…According to many studies and reports up to date, fluorosis is still a serious public health problem affecting millions of people in the world especially in regions in which high concentrations of ionic fluoride have been found in ground waters 1,4,[6][7][8] . Therefore an increasing number of patients with dental fluorosis are applying to dental clinics with esthetic expectations 9 .…”

“…In severe cases, in addition to chalky white appearence and discoloration, teeth can erupt with pits. Although teeth with mild dental fluorosis may be more resistant to dental decay, severely fluorosed teeth are more susceptible to caries most likely because of their irregular surface structure and loss of outer protective layer 1,11 .…”