Efeito do envelhecimento nas propriedades de um cimento de ionômero de vidro modificado por nanopartículas de hidroxiapatita ou por vidros bioativos 45S5
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Data
2022-03-04
Autores
Martins, Rafael Amorim
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Os cimentos de ionômero de vidro (CIV) possuem características importantes, as quais podem ser potencializadas a partir de sua associação às nanopartículas (NP) e aos vidros bioativos (VB). Considerando possíveis alterações que esta associação pode ocasionar no material restaurador em curto e em longo prazo, o objetivo deste estudo foi avaliar, antes e após envelhecimento (termociclagem após seis meses de armazenamento), propriedades físicas, mecânicas e microbiológicas de um CIV convencional (Controle) associado a 5% de NP de hidroxiapatita (NPHPa) ou a 5% de VB 45S5 (VB). A atividade antibiofilme foi definida pela contagem de unidades formadoras de colônia (UFC/ml) em 1, 7, 14 e 21 dias. A rugosidade de superfície foi estudada com auxílio de rugosímetro. Espectrofotômetro auxiliou na análise de estabilidade de cor (∆E e sistema CIELab). A porosidade foi analisada por meio do programa Image J, a partir de imagens obtidas por MEV. Dureza Vickers foi analisada por meio de microdurômetro digital. Foram realizadas também imagens em MEV e EDS para análise qualitativa e caracterização da morfologia e composição química superficial. A normalidade dos dados foi observada para todos os testes a partir da análise de Shapiro-Wilk seguido de ANOVA two-way. Para ∆E foi realizado Kruskal-Wallis. Nível de significância de 5% foi utilizado para todos os testes. Pôde-se observar diminuição de UFC/ml para todos os grupos em 14 dias antes e após envelhecimento. Inicialmente valores menores de rugosidade foram encontrados para VB, enquanto valores semelhantes foram encontrados para todos os grupos após envelhecimento. Menores valores de luminância foram encontrados para os grupos NPHPa e VB, com ∆E sem diferenças estatísticas. Quanto a porosidade, após envelhecimento, maior número de poros apresentou NPHPa embora tenha demonstrado menor área total. A dureza do Controle e NPHPa apresentou aumento dos valores após envelhecimento, tendo NPHPa os maiores. Diminuição desses valores foi observado em VB, o qual resultou em menor dureza ao final do estudo. Conclui-se que a associação do CIV a NPHPa é mais promissora e pode trazer benefícios a longo prazo.
Glass ionomer cements (GIC) have important characteristics, which can be enhanced by their association with nanoparticles (NP) and bioactive glasses (BAG). Considering the possible changes that this association can cause in the restorative material in the short and long term, the aim of this study was to evaluate, before and after aging (thermocycling after six months of storage), physical, mechanical and microbiological properties of a conventional GIC (Control) associated with 5% hydroxyapatite NP (NPHPa) or 5% BAG 45S5 (BAG). Antibiofilm activity was defined by counting colony forming units (CFU/ml) at 1, 7, 14 and 21 days. Surface roughness was studied with the aid of a rugosimeter. Spectrophotometer assisted in the analysis of color stability (∆E and CIELab system). Porosity was analyzed using the Image J program, from images obtained by SEM. Vickers hardness was analyzed using a digital microhardness meter. SEM and EDS images were also taken for qualitative analysis and characterization of morphology and surface chemical composition. Data normality was observed for all tests from the Shapiro-Wilk analysis followed by ANOVA two-way. For ∆E was performed Kruskal-Wallis. A 5% significance level was used for all tests. It was possible to observe a decrease in CFU/ml for all groups in 14 days before and after aging. Initially, lower roughness values were found for BAG, while similar values were found for all groups after aging. Lower luminance values were found for groups NPHPa and BAG, with ∆E without statistical differences. As for porosity, after aging, a greater number of pores presented NPHPa although it showed a smaller total area. The hardness of Control and NPHPa showed an increase in values after aging, with NPHPa being the highest. A decrease in these values was observed in BAG, which resulted in lower hardness at the end of the study. It is concluded that the association of GIC with NPHPa is more promising and may bring long-term benefits.
Glass ionomer cements (GIC) have important characteristics, which can be enhanced by their association with nanoparticles (NP) and bioactive glasses (BAG). Considering the possible changes that this association can cause in the restorative material in the short and long term, the aim of this study was to evaluate, before and after aging (thermocycling after six months of storage), physical, mechanical and microbiological properties of a conventional GIC (Control) associated with 5% hydroxyapatite NP (NPHPa) or 5% BAG 45S5 (BAG). Antibiofilm activity was defined by counting colony forming units (CFU/ml) at 1, 7, 14 and 21 days. Surface roughness was studied with the aid of a rugosimeter. Spectrophotometer assisted in the analysis of color stability (∆E and CIELab system). Porosity was analyzed using the Image J program, from images obtained by SEM. Vickers hardness was analyzed using a digital microhardness meter. SEM and EDS images were also taken for qualitative analysis and characterization of morphology and surface chemical composition. Data normality was observed for all tests from the Shapiro-Wilk analysis followed by ANOVA two-way. For ∆E was performed Kruskal-Wallis. A 5% significance level was used for all tests. It was possible to observe a decrease in CFU/ml for all groups in 14 days before and after aging. Initially, lower roughness values were found for BAG, while similar values were found for all groups after aging. Lower luminance values were found for groups NPHPa and BAG, with ∆E without statistical differences. As for porosity, after aging, a greater number of pores presented NPHPa although it showed a smaller total area. The hardness of Control and NPHPa showed an increase in values after aging, with NPHPa being the highest. A decrease in these values was observed in BAG, which resulted in lower hardness at the end of the study. It is concluded that the association of GIC with NPHPa is more promising and may bring long-term benefits.
Descrição
Palavras-chave
Cimentos de ionômeros de vidro, Nanopartículas, Envelhecimento, Glass ionomer cements, Nanoparticles, Aging