title: Nanoleakage and microtensile bond strength at the adhesive-dentin interface after different etching times.
abstract: OBJECTIVE
  To evaluate the effect of etching time on the nanoleakage and microtensile bond strength (microTBS) at the interface between etch-and-rise adhesives and dentin.
  
  
  METHODS
  Eighty molars were sectioned to expose the superficial dentin and randomly divided into four groups according to the adhesives used: OptiBond Solo (OB), Single Bond (SB), One-Step (OS), and Prime&Bond NT (PB). Within each group, a total-etching technique was applied, and the dentin surfaces were etched for 0, 15, 30 or 60 seconds. Each treated tooth was then sectioned into sticks. A non-trimming microTBS test and TEM observation for nanoleakage were sequentially performed.
  
  
  RESULTS
  The degree of nanoleakage increased as etching time increased (P < 0.05). For the OS and PB groups, the highest microTBS values were achieved with 15 seconds of etching, followed by 30, 60 and 0 seconds. For the OB and SB groups, the microTBS values for 15- and 30-second etching times were similar and were both significantly higher than those of 0 and 60 seconds (P < 0.05).
authors.affiliation: Department of Prosthodontics, School of Stomatology, Fourth Military Medical University, Xi'an, China.
authors.forename: San-Jun
authors.initials: SJ
authors.lastname: Zhao
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.forename: Li-Hui
authors.initials: LH
authors.lastname: Tang
authors.forename: Ji-Hua
authors.initials: JH
authors.lastname: Chen
mesh_terms: D000134:Acid Etching, Dental / Q000009:adverse effects* / Q000379:methods; D000704:Analysis of Variance; D001840:Dental Bonding; D003763:Dental Leakage / Q000209:etiology*; D003799:Dental Stress Analysis; D003804:Dentin / Q000187:drug effects* / Q000648:ultrastructure; D003806:Dentin Permeability; D017220:Dentin-Bonding Agents; D006801:Humans; D046529:Microscopy, Electron, Transmission; D008963:Molar; D010756:Phosphoric Acids / Q000009:adverse effects; D019279:Resin Cements; D013499:Surface Properties / Q000187:drug effects; D013718:Tensile Strength; D013997:Time Factors
chemical_list: D017220:Dentin-Bonding Agents; D010756:Phosphoric Acids; D019279:Resin Cements; C030242:phosphoric acid