Objective To observe the bonding interface of sclerotic dentin after treated with total- etching system and self- etching system by confocal laser scanning microscope（CLSM）. Methods A total of 12 maxillary bicuspids with non- caries, natural cervical sclerotic lesions were divided into three groups. The sclerotic dentin was bonded with Single Bond（SB, total- etching adhesive）, Clearfil SE Bond（CB, two- step self- etching）and Xeno Ⅲ（XB, onestep self - etching）according to the manufacturer′s instruction. Artificially prepared wedge - shaped lesions made in sound maxillary bicuspids and bonded with same adhesive were used as control. The primer component was labeled with Rhodamine B Isothiocyanate. Hybrid layer and resin tag of dentin bonding interface were observed by CLSM. Results Two- way ANVOA revealed significant influence of both the type of dentin and the bonding adhesive systems tested on resin tag and hybrid layer（P
