Efeito da forma geométrica da cavidade e do tipo de adesivo na microinfiltração em restaurações classe V / Effect of the geometric way of the cavity and the sticker type in the microleakage in restorations classe V

Foi avaliada "in vitro" a influência da forma da cavidade e do tipo de adesivo (frasco único e primer autocondicionante) na microinfiltração, em restaurações classe V. Em 40 incisivos bovinos, foram confeccionadas 40 cavidades com margens em esmalte, sendo 20 retangulares e 20 circulares. Em seguida, foram divididas em 4 grupos (n=10), de acordo com o adesivo e a forma geométrica: grupo 1 - circular/adesivo de frasco único; grupo 2 - retangular/adesivo de frasco único; grupo 3 - retangular/adesivo de primer autocondicionante; grupo 4 - circular/adesivo de primer autocondicionante. As cavidades foram restauradas com resina composta Tetric Ceram®, com incremento único. Em seguida, os dentes foram estocados a 37ºC, por 30 dias, e, em seguida, impermeabilizados com esmalte cosmético e imersos em solução de nitrato de prata a 50% por 2 horas, lavados e imersos em solução reveladora por 6 horas. Após isto, foram seccionados, e as amostras, analisadas em lupa estereoscópica de 25X. Os dados foram submetidos à análise estatística não paramétrica de Kruskal?Wallis (p<0,05) em que se constatou diferença estatisticamente significante entre os grupos estudados. Concluiu-se que o adesivo de frasco único associado à cavidade circular comportou-se estatisticamente significante frente às outras combinações; as cavidades circulares comportaram-se significantes em relação às retangulares.

It was evaluated ?in vitro? the shape of the cavity influence and the type of adhesive (single bottle and self-etching primer) on microleakage, in class V restorations. In 40 bovine incisors were prepared 40 cavities with margins in enamel, 20 rectangular and 20 circular. Then, were divided into four groups (n = 10) according to the adhesive and geometrical form: group 1 - circular / single bottle adhesive, Group 2 - rectangular / single bottle adhesive, Group 3 - rectangular / self-etching primer adhesive, group 4 - circular / self-etching primer adhesive. The cavities were restored with composite resin Tetric Ceram? with only one increment. Then the teeth were stored at 37?C, for 30 days, and then sealed with cosmetic nail varnish and immersed in a 50% solution of silver nitrate for 2 hours, washed and immersed in revealing solution for 6 hours. After that, the samples were sectioned and examined under stereoscopic loupe of 25X. Data were subjected to non-parametric Kruskal-Wallis statistical analysis (p <0.05) which showed statistically significant difference among the groups. It was concluded that: The single-bottle adhesive associated with circular cavity behaved statistically significant according to the other combinations, the circular cavities behaved significant in relation to the rectangular.

Effect of cavity shape, bond quality and volume on dentin bond strength / 대한치과보존학회지

The aim of this study was to evaluate the effect of cavity shape, bond quality of bonding agent and volume of resin composite on shrinkage stress developed at the cavity floor. This was done by measuring the shear bond strength with respect to iris materials (cavity shape; adhesive-coated dentin as a high C-factor and Teflon-coated metal as a low C-factor), bonding agents (bond quality; Scotchbond(TM) Multi-purpose and Xeno(R)III) and iris hole diameters (volume; 1 mm or 3 mm in diameter x 1.5 mm in thickness). Ninety-six molars were randomly divided into 8 groups (2 x 2 x 2 experimental setup). In order to simulate a Class I cavity, shear bond strength was measured on the flat occlusal dentin surface with irises. The iris hole was filled with Z250 restorative resin composite in a bulk-filling manner. The data was analyzed using three-way ANOVA and the Tukey test. Fracture mode analysis was also done. When the cavity had high C-factor, good bond quality and large volume, the bond strength decreased significantly. The volume of resin composite restricted within the well-bonded cavity walls is also be suggested to be included in the concept of C-factor, as well as the cavity shape and bond quality. Since the bond quality and volume can exaggerate the effect of cavity shape on the shrinkage stress developed at the resin-dentin bond, resin composites must be filled in a method, which minimizes the volume that can increase the C-factor.