Trends in restorative composites research: what is in the future?

Abstract Clinical trials have identified secondary caries and bulk fracture as the main causes for composite restoration failure. As a measure to avoid frequent reinterventions for restoration replacement, composites with some sort of defense mechanism against biofilm formation and demineralization, as well as materials with lower susceptibility to crack propagation are necessary. Also, the restorative procedure with composites are very time-consuming and technically demanding, particularly concerning the application of the adhesive system. Therefore, together with bulk-fill composites, self-adhesive restorative composites could reduce operator error and chairside time. This literature review describes the current stage of development of remineralizing, antibacterial and self-healing composites. Also, an overview of the research on fiber-reinforced composites and self-adhesive composites, both introduced for clinical use in recent years, is presented.

Ação do pH do cimento de hidróxido de cálcio / Action pH of calcium hydroxide cement

O cimento de hidróxido de cálcio é utilizado em capeamento pulpar nas cavidades profundas. Sua propriedades bactericida e mineralizadora são dependentes do seu pH alcalino. O objetivo deste estudo foi de realizar uma análise do pH de três marcas comerciais de cimentos de hidróxido de cálcio (Hidro C; Hydcal: Liner) em diferentes períodos de tempo para averiguar a eficácia de cada uma como material terapêutico. Dez amostras de cada material foram preparadas usando a matriz de teflon, em forma de disco com orificio central de 3,5mm de diâmetro e 2,0mm de espessura, armazenadas em 10ml de água destilada em uma estufa a 37°C. Os dados coletados foram submetidos a uma análise de variância a dois critérios e utilizado o teste de Tukey para comparação dos valores individuais de cada variável. Na primeira hora os cimentos apresentaram o pH elevado e nos demais períodos houve um declínio em todos cimentos para um patamar próximo de pH 8. Ainda assim o pH é influente na ação mineralizadora e bacteriana. Como significância clínica pode inferir que os materiais testados Hidro C, Hydcal e Liner são semelhantes e qualquer um deles cumpre a sua finalidade terapêutica

The calcium hydroxide cement is used for pulp-capping in deep cavity preparations. Its bactericide and mineralizing properties depends on the alkaline pH. The aim of this study is to analyze the concentration of hydrogen ions (pH) of three calcium hydroxide cement brands (Hidro C, Hydcal and Liner) over different periods of time to evaluate the efficacy of each brand as a therapeutic material. Ten specimens of each brand were fabricated using a Teflon mould with a diameter of 3,5mm and 2mm thickness, and stored in distilled water (10ml) at 37°C. The results were analyzed with analysis of variance (ANOVA) and Tukey’s test in order to compare the individual values of every variable. At the 1st hour the specimens presented a high pH and through the other periods of time they had a decline on the pH means to a pH 8, approximately. Even with that decline, the pH influences the bactericide and mineralizing action over the dentin-pulp complex. Based on the results obtained, it can be imply that all the tested materials (Hidro C, Hydcal and Liner) are similar and achieve its therapeutic objective