Effect of erbium-doped: yttrium-aluminum-garnet laser preparation on resin-cavity interface using a universal adhesive evaluated by swept source optical coherence tomography

Shigeyuki Nagai, DDS,a Masayuki Otsuki, DDS, PhD,a Alireza Sadr, DDS, PhD,b Yasushi Shimada, DDS, PhD,a Juri Hayashi, DDS,a Junji Tagami, DDS, PhD,a and Yasunori Sumi, DDS, PhDc

aDepartment of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan, bDepartment of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, WA, USA, and cCenter of Advanced Medicine for Dental and Oral Diseases, National Center for Geriatrics and Gerontology, Obu, Japan

Purpose: The purpose of this in vitro study was to evaluate cavity adaptation between erbium-doped: yttrium-aluminum-garnet (Er:YAG) laser irradiated cavity and composite resin using a universal type adhesive with different application by means of a swept source optical coherence tomography (SS-OCT).Materials and Methods: A cylindrical cavity was prepared on the labial surface of extracted bovine incisor by either rotary cutting instrument or Er:YAG laser. The cavity was applied by either two-step self-etching adhesive (Clearfil SE Bond, CS) or universal type adhesive (Schotchbond Universal, SU), as self-etching or selective enamel etching, and then was restored with a flowable composite resin. Gap formation of enamel and dentin interface was evaluated by an SS-OCT. Results: At the enamel interface, there are no statistical differences between bur preparation and laser preparation in each group. For bur prepared SU groups, selective enamel etching showed less gap formation than self-etching group. At the dentin interfaces, there are no statistical differences between bur preparation and laser preparation. Selective enamel etching did not affect gap formation at dentin. On lased dentin, CS showed better adaptation compared to SU.Conclusion: It was concluded that the universal type adhesive showed comparable adaptability to tooth substrate prepared by bur and laser, and selective enamel etching improved adaptation to bur prepared enamel in case of a universal type adhesive.Conclusion: Application of the resin coating to dentin surface demonstrated remarkable reduction of dentin permeability over time.
(Asian Pac J Dent 2015; 15: 41-50.)
Key Words: Er:YAG laser, gap formation, selective enamel etching, SS-OCT, universal type adhesive