Effect of three dentin adhesives on marginal adaptation of two light-cured composites

The marginal adaptation of two light-cured composites, Silux and P-30, was tested in butt-joint dentin cavities prepared in extracted human teeth. The cavity diameter ranged from 1.8 mm to 6.3 mm. Only minor differences were found between the marginal contraction gap of Silux and P-30 when used without previous application of a dentin adhesive. The light-cured Scotchbond proved to be as effective as GLUMA in reducing the contraction gaps of Silux providing the smear-layer was partly removed, the adhesive polymerized for 50 s and finally wetted with Silux Enamel Bond prior to application of Silux. Both adhesives had markedly less effect on the contraction gaps of the highly filled P-30.