title: Ethanol-wet bonding may improve root dentine bonding performance of hydrophobic adhesive.
abstract: OBJECTIVE
  The current study aimed to assess ethanol-wet dentine surfaces by atomic force microscopy (AFM), and to evaluate the efficacy of ethanol-wet bonding on root dentine by determining the shear bond strength (SBS) and interfacial nanoleakage expression.
  
  
  METHODS
  Flat dentine slices from human premolar roots were randomly grouped into five. All specimens were acid-etched, rinsed, and left moist. They were then treated with 100% ethanol for 0s (control group), 20s (Group 1), 60s (Group 2), three 60s periods (Group 3), or stepwise ethanol application (Group 4). After treatment, each group was bonded either with Adper™ Scotchbond™ Multi-Purpose (Scotchbond) or experimental hydrophobic adhesive. Nano-scale adhesion forces (Fad) were probed by AFM and analysed using one-way ANOVA. The SBS results were analysed using two-way ANOVA. Tukey's test was employed for multiple comparisons.
  
  
  RESULTS
  Ethanol-wet protocols significantly decreased the value of Fad (p<0.001). When bonded with Scotchbond, ethanol treatment did not affect the bond strength (p>0.05), but decreased the interfacial nanoleakage. The SBS values of the groups bonded with hydrophobic adhesive varied with different ethanol-wet protocols (p<0.05). Decreased nanoleakage was manifested in all experimental groups, except Group 1. Compared with the classical water-wet bonding with Scotchbond in the control group, Group 4 bonded with hydrophobic adhesive exhibited a significantly higher bond strength (p<0.05).
  
  
  CONCLUSIONS
  Ethanol-wet bonding using a stepwise ethanol application protocol may have potential benefits in the root dentine bonding of hydrophobic adhesive.
authors.affiliation: Department of Prosthodontics, School of Stomatology, Wuhan University, Wuhan, China.
authors.forename: Dandan
authors.initials: D
authors.lastname: Pei
authors.forename: Xueqing
authors.initials: X
authors.lastname: Huang
authors.forename: Cui
authors.initials: C
authors.lastname: Huang
authors.forename: Yake
authors.initials: Y
authors.lastname: Wang
authors.forename: Xiaobai
authors.initials: X
authors.lastname: Ouyang
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
mesh_terms: D010129:4-Aminobenzoic Acid / Q000737:chemistry; D000134:Acid Etching, Dental / Q000379:methods; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding / Q000379:methods*; D003763:Dental Leakage / Q000145:classification; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry; D000431:Ethanol / Q000737:chemistry*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D036103:Nanotechnology; D010756:Phosphoric Acids / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D033081:Shear Strength; D016622:Silver Staining; D012997:Solvents / Q000737:chemistry*; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors; D014092:Tooth Root / Q000648:ultrastructure*; D014867:Water / Q000737:chemistry; D062366:para-Aminobenzoates
chemical_list: C084111:Charisma composite resin; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D010756:Phosphoric Acids; D011109:Polymethacrylic Acids; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; D012997:Solvents; C523330:ethyl 4-N,N-dimethylaminobenzoate; D062366:para-Aminobenzoates; D014867:Water; C020946:triethylene glycol dimethacrylate; D000431:Ethanol; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; C030242:phosphoric acid; D010129:4-Aminobenzoic Acid