Takeshi Shinoki, DDS,a Junji Kato, DDS, PhD,a Masayuki Otsuki, DDS, PhD,a and Junji Tagami, DDS, PhDa,b
aCariology and Operative Dentistry, Department of Restorative Sciences, Graduate School of Medical and Dental Sciences, and bGlobal Center of Excellence (GCOE) Program; International Research Center for Molecular Science in Tooth and Bone Diseases, Tokyo Medical and Dental University, Tokyo, Japan
Purpose: The purpose of this in vitro study was to evaluate the effect of cavity preparation with erbium-doped: yttrium-aluminum-garnet (Er:YAG) laser on marginal integrity of resin composite restorations.
Materials and Methods: Twenty-one extracted human molars were divided in three groups and saucer-shaped cavity approximately 1.5 mm in depth and 2 mm in diameter was prepared on the mid-coronal surface of each tooth by Er:YAG laser at 150 mJ/10 pps, 200 mJ/10 pps or a diamond bur. After restoration with a self-etch adhesive and a resin composite, enamel cracks and gap formations at the cavosurface margin were evaluated using a digital microscope on the surface and the crosscut surface of the restoration.
Results: The cavities prepared by a diamond bur caused more enamel cracks and gap formations than lased cavities at 150 mJ/10 pps. There were no statistical differences of crack and gap formation between restored cavities by Er:YAG laser at 150 mJ and 200 mJ.
Conclusion: It was concluded that the preparation by Er:YAG laser at suitable output energy showed the better marginal integrity of resin composite restorations than that by a rotary cutting instrument.(Asian Pac J Dent 2011; 11: 19-25.)
Key Words: composite resin, laser, marginal integration