Marginal accuracy of provisional restorative materials.

Marginal integrity is an important quality in the provisional restoration. Previous studies on marginal integrity have presented conflicting results. In addition, newly available resins are making the selection of an accurate resin for provisional restorations difficult. The objective of this study was to evaluate the marginal accuracy of seven commercially available resins by using an established indirect technique, and to evaluate the effect of water absorption on polymerization shrinkage. Eight specimens of each material were tested under three conditions: immediately after polymerization, after 1 week of dry storage, and after 1 week of storage in room temperature water. Three materials, Duralay, Cold Pac, and Snap resins, produced statistically significantly superior marginal adaptation. Water absorption appeared to compensate for continued polymerization shrinkage.