Marginal leakage with different composite restorative materials: effect of restorative techniques.

The degrees of marginal leakage was tested for different restorative techniques with use of both ultraviolet-polymerized and cold-curing resins. All the materials tested showed severe marginal leakage when applied as conventional butt joint restorations. When the restorations were extended onto peripheral etched enamel, either with or without a sealant-primed etched surface, marginal leakage was prevented in most instances with both the cold-curing and ultraviolet-polymerized materials. However, the ultraviolet-polymerized sealant was more effective in preventing marginal leakage than the cold-curing sealants when applied as a covering over the restorations and extended onto the peripheral etched enamel.

Marginal leakage with different composite restorative materials in vitro. Effect of cavity design.

In this preliminary study the degree of marginal leakage was assessed for different cavity designs using both ultra violet-curing and self-curing composite restorative materials and sealants. Butt joint restorations placed in etched and sealant primed cavities failed to prevent leakage. Both saucer-shaped and funnel-shaped cavities and cavities with rounded margins were able to prevent leakage when the restorations were bonded to etched and sealant primed peripheral enamel. Further, less than 1 mm of gingival enamel available for bonding seemed to be sufficient in most instances to prevent leakage.

Adhesive penetration in human artificial and natural white spots.

Penetration of a liquid adhesive into human artificial and natural white spots, both acid-conditioned and nonconditioned, was studied. All artificial white spots showed penetration of the adhesive. Acid-conditioned natural lesions exhibited penetration to a lesser amount than in vitro lesions. Penetration in nonconditioned natural lesions was not apparent.