The goal of this study was to evaluate the bonding resistance of two dental ceramics. The samples, one of each type of ceramics, were split into 4 groups (n=4) separated from those from control group, the others were conditioned with 5% hydrofluoric acid, according to the times of 20, 40 and 60 seconds. Cylindrical pins of resin cement were applied in each sample. After a shearing test, the obtained results showed that experimental groups has given higher bonding strength values than the control groups for both ceramics. For the e.max ceramic, the highest values were observed with timings of 20 and 40 seconds and for the Suprinity ceramic the conditioning timings were insignificant. The authors concluded that the surface treatment with hydrofluoric acid improved the bonding strength for both ceramics; and the e.max ceramic showed higher bonding values than the Suprinity.
RESUMO O presente estudo visou caracterizar a interface entre resina e substrato dentário submetida aos processos restauradores convencional e autocondicionante, levando a observar a presença de gaps e infiltração dos sistemas adesivos nos substratos dentários. A análise foi realizada em dois substratos dentários: o esmalte e a dentina. Seis dentes hígidos, previamente coletados e armazenados, foram seccionados em três planos de corte distintos para avaliar a adesão em relação à morfologia dentária. Para isto, foi utilizado um sistema adesivo universal aplicado de maneira convencional e autocondicionante. A técnica autocondicionante não é eficiente em esmalte, apresentando formação de gaps. Já a convencional é mais eficiente devido ao processo de desmineralização por um ácido forte, ocasionando a penetração do adesivo. Para a dentina, a técnica convencional formou uma camada híbrida espessa, irregular e com penetração de tags resinosos e a autocondicionante formou uma camada híbrida mais fina, homogênea e sem tags. O tamanho da camada híbrida e penetração dos tags não influenciam na resistência adesiva, sendo este fator dependente da qualidade da camada híbrida e sua interação com o substrato.
The goal of this study was to characterize the mechanical behavior of dentin, dental enamel and a nanoparticulate composite resin, used in dental restorations. This characterization was performed through the static and dynamic Vickers hardness test. As for the biological tissue assays, third included human molars were used. The nanoparticulate resinous composite was condensed into a matrix, measuring approximately 10x10x2mm. The obtained HV values were represented by hardness maps. The distribution of hardness values along the enamel and dentin structures occurred unevenly in the two hardness analyzes. For dental enamel, there were differences in hardness values when compared dynamic to static tests. This difference did not occur in dentin. It was observed that the mechanical behavior of the resinous composite resembled more the behavior of the dentin than the enamel.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.