The effect of VLC Scotchbond and an incremental filling technique on leakage around Class II composite restorations

The object of this study was to determine the effect of VLC Scotchbond and of an incremental filling technique on microleakage around class II composite restoration in vitro. Four groups of 15-16 teeth each, were filled with the resin P-30 by one of the following techniques: A, Scotchbond and incremental filling; B, Scotchbond and bulk filling; C, Enamel Bond and incremental filling; D, Enamel Bond and bulk filling. The teeth were thermocycled, insulated up to 1 mm from the restorations, immersed in 2 percent basic fuchsin, embedded in acrylic resin and ground off to various depths, parallel to the plane through the vertical and the mesiodistal axes. Marginal leakage was assessed from the degree of dye penetration at the sections. Dye penetration at the occlusal margins was similar for all groups. Dye penetration at the cervical margins for the different groups increased in the sequence: A/C/B/D. Incremental filling resulted in a significantly lower dye penetration at cervical margins for both bonding agents. The differences resulting from the use of Scotchbond were not significant, if the same packing technique had been used. Best results were obtained with Scotchbond and incremental filling.