Microleakage of tooth-colored restorations with a beveled gingival margin

Objective: Microleakage of tooth-colored restorative systems was tested in preparations with and without beveled gingival margins. Method and materials: A resin composite, Z-100, and two "compomer" restoratives, Dyract and Geristore, with their accompanying adhesive systems, were placed in nonretentive cervical cavity preparations (at the cementoenamel junction), with and without a beveled gingival margin (dentin or cementum) and beveled occlusal (enamel) margins in extracted bovine teeth. Microleakage was assessed as the ratio of the extent of methylene blue dye penetration at the tooth-restoration interface to the length of the wall. Results: Z-100 restorations, without a gingival bevel, exhibited significantly less microleakage along the gingival wall and less microleakage overall than did the other materials. Dyract restorations,without a gingival bevel and placed without a surface conditioner displayed greater microleakage overall than did the other groups. Conclusion: With all materials, Class V restorations with gingival bevels displayed greater microleakage than did nonbeveled margins.