title: Ethanol-wet bonding technique may enhance the bonding performance of contemporary etch-and-rinse dental adhesives.
abstract: OBJECTIVE
  To determine whether bonds of contemporary etch-and-rinse adhesives made with ethanol-wet bonding are stronger and more durable than those made with water-wet bonding, and to explore the possible reasons for the bonding results.
  
  
  METHODS
  Flat surfaces of midcoronal dentin were made in extracted human third molars. The dentin surfaces were randomized into 6 groups according to bonding techniques (water- vs ethanol-wet bonding) and dental adhesives [Single Bond 2 (SB), Prime Bond NT (PB), and Gluma Comfort Bond (GB)]. After etching and rinsing, dentin surfaces were either left water-moist or immersed in ethanol. Following adhesive application and composite buildups, the bonded teeth were sectioned into beams for microtensile bond strength evaluation with or without NaOCl challenge. The morphology of the hybrid layer was analyzed with SEM. The wettability of water- vs. ethanol-saturated dentin was evaluated. The concentrations of non-volatile ingredients in the adhesives were compared.
  
  
  RESULTS
  Compared to water-wet bonding, ethanol-wet bonding yielded similar (p > 0.05 for PB and GB) or higher (p < 0.05 for SB) 24-h bond strength, displayed significantly higher bond strength after chemical challenge (p < 0.05, for all three adhesives), and produced more even hybrid layers. Moreover, ethanol-saturated dentin exhibited a lower contact angle than water-saturated specimens, and the concentrations of non-volatile ingredients of the adhesives decreased in the order of SB > GB > PB.
  
  
  CONCLUSIONS
  Ethanol-wet bonding could improve the bonding efficacy of contemporary etch-and-rinse adhesives, probably due to the good wettability of ethanol-saturated dentin and the structure of the hybrid layer. Moreover, this positive effect of ethanol-wet bonding might be influenced by the composition of adhesives.
authors: Department of Prosthodontics, School of Stomatology, Fourth Military Medical University, Xi'an, China.
authors: Fang
authors: F
authors: Li
authors: Xiao-Yang
authors: XY
authors: Liu
authors: Ling
authors: L
authors: Zhang
authors: Jun-Jun
authors: JJ
authors: Kang
authors: Ji-Hua
authors: JH
authors: Chen
mesh_terms: D000134:Acid Etching, Dental; D000704:Analysis of Variance; D017438:Bisphenol A-Glycidyl Methacrylate; D001840:Dental Bonding / Q000379:methods*; D003799:Dental Stress Analysis; D003806:Dentin Permeability; D017220:Dentin-Bonding Agents / Q000737:chemistry; D000431:Ethanol; D006801:Humans; D008422:Materials Testing; D011109:Polymethacrylic Acids; D018709:Statistics, Nonparametric; D013718:Tensile Strength; D014867:Water; D017155:Wettability
chemical_list: D017220:Dentin-Bonding Agents; C445021:Gluma Comfort Bond; D011109:Polymethacrylic Acids; C425843:Prime and Bond NT; C115612:single bond; D014867:Water; D000431:Ethanol; D017438:Bisphenol A-Glycidyl Methacrylate