Efeito da incorporação do trimetafosfato de sódio microparticulado e nanoparticulado ao cimento de ionômero de vidro nas propriedades físico-mecânicas e na desmineralização do esmalte

• Autor(a) principal: Abreu, Valéria Marisel de [UNESP]
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/134202; http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/28-01-2016/000857869.pdf
• topic: Cimentos de ionômeros de vidro; Desmineralização do dente; Polimerização; Fosfatos; Nanopartículas; Força compressiva; Dental glass ionomer cements

The aim of this study was to evaluate the effect of addition of sodium trimetaphosphate (TMP) microparticle (m) and nanoparticle (n) to the glass ionomer cement (GIC) on the physico-mechanical properties and demineralization of the enamel. Specimens (n=54) were fabricated from each experimental group: GIC without TMP (GIC), GIC with 3.5%, 7% and 14% TMPm and GIC with 3.5%, 7% and 14% TMPn. To determine the release of fluoride (F) and TMP it was used six specimens immersed into a demineralization and remineralization solution during 15 days. The physico-mechanical properties evaluated 24 hours and 7 days after fabrication were: compressive strength (n=12), diametral tensile strength (n=12), surface hardness of material (n=6) and the degree of conversion of monomers (n=6). For the study of enamel demineralization, specimens (n=12) were attached to enamel blocks selected by the initial surface hardness test (SH1) and submitted to the pH-cycling. Following, final surface (SH2) and cross-sectional (CSH) hardness, as well as enamel F concentration were determined. Parametric and non-parametric tests were performed after checking the data homoscedasticity (p<0.05). The addition of 14% TMP led to higher mean release of F (p<0.05) and the other groups were similar to the GIC (p>0.05). The release of TMP was higher with 14% microparticulate (p<0.05). The addition of TMP at GIC promoted an average reduction of mechanical properties of 21% (tensile), 10% (compressive) and 18% (hardness) after 24 hours and 18%, 23% and 12% after 7 days. The degree of conversion was lower with addition of 14% TMP compared to the GIC after 24 hours (p<0.05); at 7 days there was no difference between groups (p>0.05). Addition of 7% and 14% TMP reduced mineral loss and increased enamel F concentration when compared...