Efeito de soluções suplementadas com hexametafosfato de sódio microparticulado sobre a energia livre de superfície do esmalte dentário

• Autor(a) principal: Figueiredo, Leonardo Raniel [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/11449/156681; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2018-06-12/000901300.pdf
• topic: Esmalte dentário; Fluoretos; Fosfatos; Dental enamel

The phosphates have the ability to modify the surface of the hydroxyapatite (HA), through its adsorption on the enamel. The objective of this study was to evaluate the adsorption capacity of microparticulate sodium hexametaphosphate (HMP) associated with fluoride (F) and surface free energy (SFE) on dental enamel through a study In vitro. Bovine enamel blocks (4 mm x 4 mm, n = 96; 12 blocks/group) were obtained and selected and then immersed in solutions (1 minute, 1mL/group) containing micrometric (HMP) at 0% concentrations; 0.25%; 0.5%; 1%. These concentrations of HMP were associated or not to F at the concentration of 1100 ppm F. The free surface energy (mN/m) was calculated by measuring the contact angles of the three probes liquids: deionized water, diiodomethane and ethylene-glycol; The polar and non-polar components of the enamel surface were determined. The data presented normal distribution (Kolmogorov-Smirnov) and homogeneous (Cochran) and then were submitted to ANOVA followed by Student-Newman-Keuls test (p<0.001). Treatments with solutions containing HMP alone promoted lower contact angles for the three liquid probes compared to the non-treated group (p<0.001). The values of the non-polar component (SLW) obtained from the enamel surface were higher after treatment with HMP (p = 0.001), where as for the polar component (SAB) the values became more negative with % HMP (p<0.017). Addition of HMP to F reduced enamel SFE at concentrations of 0.25% and 0.5% (p<0.003). It is concluded that the adsorption of HMP in the enamel increases the free surface energy, and when associated with F occurs an increase in the electron donor sites facilitating the adsorption of calcium and/or calcium phosphate