Effect of dentin depth on hybridization quality using different bonding tactics in vivo

Objectives Incomplete resin infiltration and polymerization of adhesive contributed to nanoleakage formation. This study tested the null hypothesis that adoption of different bonding tactics and dentine depth will not affect hybridization quality in vivo. Methods Class V cavities were prepared on the labial/buccal surface of monkey teeth. They were bonded by Single Bond (a two-step total-etch adhesive), Clearfil SE Bond (a two-step self-etch adhesive), or Clearfil S3 Bond (an all-in-one self-etch adhesive). Combined nanoleakage analysis and quantitative immunolabeling evaluation were carried out in the hybrid layer formed in both cervical superficial and deep dentine. Results Single Bond showed reticular and spotted nanoleakage while Clearfil SE Bond and Clearfil S3 Bond presented only a spotted one. While Single Bond showed increased concentration of labeling of type I collagen within the deep part of the hybrid layer, two self-etch adhesives—Clearfil SE Bond and Clearfil S3 Bond revealed a homogeneous labeling pattern, even if the latter presented a significantly increased labeling index in deep dentine. Conclusions Different bonding tactics showed different nanoleakage patterns and immunolabeling index, and was influenced by dentine depth at different levels in vivo.