title: [Nanoleakage at the resin-dental interface of four self-etching adhesives].
abstract: OBJECTIVE
  To evaluate the nanoleakage and ultramorphology of four self-etching adhesives.
  
  
  METHODS
  Sixteen freshly extracted, caries-free human third molars were selected. A flat dentin surface was exposed by removing occlusal enamel. All teeth were randomly divided into four groups acorrding to four different self-etch adhesive: Adper Prompt (A), iBond (B), Xeno III (C) and SE Bond (D). The dentin were bonded with dentin adhesive system according to manufacturer's directions. Composite layers were built up incrementally. The specimens were sectioned longitudinally across the resin-dentin interface into 4.0 mm×0.9 mm sticks and then traced with ammoniacal silver solution. Epoxy resin-embedded sections were prepared for transmission electron microscope (TEM) to observe nanoleakage. The images were qualitatively compared by NIH software, and data was analyzed by SPSS.
  
  
  RESULTS
  Different thickness of hybrid layer and adhesives layer were observed for each adhesive. The hybrid layer of A, C was thicker than that of B, D, and adhesive layer of D was thicker than the others. The extent of nanoleakage varied among different adhesives: A (45.02 ± 9.49), B (43.97 ± 8.55), C (27.02 ± 10.86), D (12.94 ± 2.07). D presented significantly less silver deposition than any of the others did (P < 0.05).
  
  
  CONCLUSIONS
  The thickness of hybrid layer and adhesive layer vary among the four adhesives. The shape and extent of nanoleakage of each adhesive are also different. Two-step system shows less nanoleakage than one-step systems do.
authors.affiliation: Department of Preventive Dentistry, Guanghua School and Hospital of Stomatology & Institute of Stomatological Research, Sun Yat-sen University, Guangzhou, China.
authors.forename: Zhi-qing
authors.initials: ZQ
authors.lastname: Liao
authors.forename: Yong
authors.initials: Y
authors.lastname: Ouyang
authors.forename: Jian-zhen
authors.initials: JZ
authors.lastname: Yang
mesh_terms: D000134:Acid Etching, Dental; D000269:Adhesives / Q000737:chemistry*; D003763:Dental Leakage / Q000473:pathology*; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D008689:Methacrylates / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D008964:Molar, Third; D019279:Resin Cements / Q000737:chemistry
chemical_list: D000269:Adhesives; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D019279:Resin Cements; C096371:Sebond; C487957:Xeno III; C477386:iBond