Análise da dureza e liberação de fluoreto e fosfato do cimento de ionômero de vidro contendo hexametafosfato de sódio

• Autor(a) principal: Morais, Leonardo Antônio de [UNESP]
• Data de Publicação: 2017
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/156680; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2018-06-12/000901293.pdf
• topic: Cimentos de ionômeros de vidro; Fluoretos; Fosfatos; Fluorides

The objective of this study was to evaluate the effect of the incorporation of sodium hexametaphosphate (HMP) microparticle (M) and nanoparticle (N) on glass ionomer cement (GIC) on the hardness and release of fluoride (F) and HMP. Six specimens of each material were prepared: GIC without HMP (GIC); GIC with 6%, 9% and 12% HMP M; GIC with 6%, 9% and 12% HMP N. The specimens were placed in tubes containing 2 mL of the solutions DES (6 hours) or RE (18 hours) under constant shaking. These procedures were repeated during 15 days. The solutions were collected daily and stored to measure fluoride and HMP release. For the hardness analysis, 6 specimens of each material were made and after 1 day submitted to the surface hardness test. Then, the specimens were stored in an oven at 37ºC and after 7 days the hardness test was repeated. The release data of F and HMP showed heterogeneous distribution and were submitted to analysis of variance (2-criteria) followed by the Student-Newman-Keuls test. The hardness results presented normal distribution (Shapiro-Wilk test) and homoscedasticity (Cochran test) after logarithmic transformation and were submitted to analysis of variance (2-criteria) followed by Student-Newman-Keuls test. All analyzes were performed with the SigmaPlot 12.0 program with a significance level of 5%. Regarding the release of F, the highest values occurred on the first day in all groups (p<0.05). The mean total F released during the 15 days was higher in the HMP group 12% N (p<0.05) followed by the HMP 9% N (p<0.05). Analysis of the release of total HMP in the cycling solutions by the materials showed that the groups containing HMP N had higher values (p<0.05) when compared to the M. The highest mean HMP release (p<0.05) occurred in the groups containing 9 and 12% of HMP N being similar to each other (p>0.05). The incorporation of the HMP to the GIC reduced...