Reduction of cervical gaps in class II composite resin restorations.

Class II cavities prepared in brass models and in extracted teeth were restored with three light-cured composite resins. A transparent cone-shaped device (Light-tip) at the end of the light source was pressed into the filling material in the proximal box for curing the resin. A second layer was filled in the recess left by the cone and cured without the cone. Controls consisted of fillings cured in two layers. In the brass cavities the contraction gap was 10 microns (+/- 10.6) with use of the cone compared with 109.5 microns (+/- 46.5) in control fillings (p less than 0.001). Extracted teeth were restored without etching of the enamel. Cervical contraction gaps in control restorations were reduced by more than half with the use of the transparent cone technique.