ABSTRACT
Abstract Mineral trioxide aggregate (MTA) has many clinical applications in dentistry; the main drawback is the long setting. The main objective is to investigate and compare the chemical effect of using two commercially available hyaluronic acid hydrogels (HA) instead of distilled water for mixing MTA as an accelerant of setting time. Materials and method: Test materials were divided into three groups; Group 1: (control) mixing MTA with distilled water supplied by the manufacturer; Group 2: mixing MTA with a hybrid cooperative complex of high and low molecular weight HA (Profhilo®); Group 3: mixing MTA with High molecular weight / non-cross-linked HA (Jalupro®). Mixing time, and setting time (initial and final) were determined, Fourier-transform infrared spectroscopy, Energy-dispersive X-ray spectroscopy, Field emission Scanning Electron Microscopy, and X-ray diffraction were performed. Results: mixing time, initial, and final setting time for (MTA + HA) groups were significantly different and lower in comparison to the control group (p < 0.05). This study revealed higher expression of calcium silicate hydrate and calcium hydroxide expression with higher Ca release in the MTA + HA group than the control group. Conclusion: commercially available HA demonstrated better chemical properties when used as a mixing medium for MTA. The Mixing and setting time for MTA + HA group were significantly shorter than those of the control group were. Thus, commercially available HA can be used as a mixing medium for MTA.
Resumo O agregado de trióxido mineral (MTA) tem muitas aplicações clínicas em odontologia, mas a principal desvantagem é a longa presa. O objetivo principal é investigar e comparar o efeito químico do uso de dois hidrogéis de ácido hialurônico (HA) disponíveis comercialmente em vez de água destilada para misturar o MTA como um acelerador do tempo de presa. Materiais e método: Os materiais de teste foram divididos em três grupos: Grupo 1: (controle) misturando o MTA com água destilada fornecida pelo fabricante; Grupo 2: misturando o MTA com um complexo cooperativo híbrido de HA de alto e baixo peso molecular (Profhilo®); Grupo 3: misturando o MTA com HA de alto peso molecular/não reticulado (Jalupro®). Foram determinados o tempo de mistura e o tempo de presa (inicial e final), a espectroscopia de infravermelho com transformada de Fourier, a espectroscopia de raios X com dispersão de energia, a microscopia eletrônica de varredura com emissão de campo e a difração de raios X. Resultados: o tempo de mistura, o tempo de presa inicial e final dos grupos (MTA + HA) foram significativamente diferentes e menores em comparação com o grupo de controle (p < 0,05). Esse estudo revelou maior expressão de silicato de cálcio hidratado e expressão de hidróxido de cálcio com maior liberação de Ca no grupo MTA + HA do que no grupo de controle. Conclusão: a HA disponível comercialmente demonstrou melhores propriedades químicas quando usada como meio de mistura para o MTA. O tempo de mistura e de presa do grupo MTA + HA foi significativamente menor do que o do grupo de controle. Portanto, a HA disponível comercialmente pode ser usada como meio de mistura para o MTA.
ABSTRACT
Objectives: The aim of this study was to evaluate chemical and topographical changes in the intaglio zirconia surface induced by chemical conditioning solutions using FTIR and SEM analysis. Material and method: twelve plates for each FTIR and SEM tests from each zirconia materials (UPCERA HT White, BruxZir® Solid Zirconia, and Copran® Multilayer), milled by a Yenadent CAD/CAM system, sintered and divided randomly into a three groups. A different surface conditioning was applied to the intaglio surface of each group: 30% hydrogen peroxide, 30% citric acid and control group. Result and discussion: by using of the FTIR spectroscopy, an evidence of new bands formation appeared at 1637cm-1 and 3352cm-1 due to the high oxidizing effect of hydrogen peroxide, and at 630cm-1 and 1663cm-1 due to the chelating action of citric acid, and simultaneously, SEM assessment of the surface topography took place, to identify lines, scratches, or surface dissociation that appeared on the intaglio zirconia surface after conditioning. Conclusion: such analysis provides an enhancement of new convenient, less expensive, reliable trials to improve micro-bond strength of luting cement to Y-TZP ceramics.