Avaliação da eficácia de dentifrício de baixa concentração de fluoreto suplementado com hexametafosfato de sódio sobre a desmineralização do esmalte: estudo in vitro

• Autor(a) principal: Miyasaki, Marcela Lumi [UNESP]
• Data de Publicação: 2011
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/149346; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2017-01-26/000839563.pdf
• topic: Desmineralização do dente; Esmalte dentário; Dentifrícios; Fluoreto de sódio; Fosfatos; Tooth demineralization

The involuntary ingestion of dentifrice by children under six years of age has been considered a risk factor for the development of dental fluorosis. The use of dentifrices with low concentrations of fluoride (F) helps to decrease the ion intake by children who do not yet have full control of expectoration. Recent studies have shown that dentifrice containing 500 μgF/g supplemented with sodium hexametaphosphate (HMP) present similar efficacy of a dentifrice with 1100 μgF/g in the reduction of enamel demineralization in vitro. The objective of this study was to evaluate the efficacy of dentifrices with lower concentrations of F supplemented with different concentrations of HMP on the bovine tooth enamel demineralization through pH cycling model. Enamel blocks were prepared from bovine teeth, surface microhardness was measured and then the blocks were subjected to repeated cycling of alternated pH with daily treatments with dentifrices containing 250 μgF/g between 0 and 3% HMP; A dentifrice without the addition of F and HMP (placebo) and a commercial (Crest , the 1100 μgF/g) were also used. After the pH cycling it was determined the surface microhardness, calculating the percentage change of surface microhardness (% SMH). The results were submitted to ANOVA and Tukey tests and the level of significance was set at 5% (p <0.05). It was observed that the group 250 μgF/g with 0.5% HMP showed lower percentage of surface microhardness change (% SMH), followed by the group of 250 μgF/g with 1.0% HMP that was similar to that Crest . The addition of 0.5% HMP to a dentifrice without F promoted a lower percentage of surface microhardness change compared to placebo. We conclude that it is possible to reduce the concentration of F to 250μgF/g to obtain comparable action of a commercial dentifrice on the demineralization of bovine enamel through the supplementation with hexametaphosphate at concentrations of 0.5 and 1%