The effect of composite resin application and radiation techniques on dye penetration in Class II direct composite resin restorations.

This study examined the effect of the application of resin composite and radiation techniques on dye penetration in class II direct composite resin restorations. For the restorative procedure, the light-cone and the incremental layering techniques were used. The null hypothesis of this experiment was, that both techniques have the same influence on dye penetration. Evaluation of dye penetration in the restoration/tooth interface was performed in 20 extracted premolars and molars. On each tooth, two class II cavities were prepared. The cervical margin of the proximal boxes were located in dentin or in enamel. When the gingival margin of the cavity was located in enamel, a significant lower level of dye penetration of the the test group was found (Wilcoxon rank test, P = 0.0102). This study showed that the application of a transparent cone seems to be more effective than the three increments technique in the mechanical separation of the first composite increment. Transmitting the curing light into the proximal box, seems to have no positive effect on dye penetration in class II direct composite resin restorations.