title: [Study on the micropermeability of resin-dentin bonding interfaces with ethanol-wet bonding technique].
abstract: OBJECTIVE
  To evaluate the micropermeability on bonding hydrophobic adhesive to dentin with ethanol-wet bonding under simulated pulp pressure.
  
  
  METHODS
  Twenty-four intact human third molars were used in the study. After the enamel of occlusal surfaces was removed, the molars were randomly divided into six groups. Adper Scotchbond Multi-Purpose was used in the control group; in the experimental groups, the dentin surfaces were saturated with ethanol for 20 s (group 1), 1 min (group 2), 2 min (group 3), 3 min (group 4) or with a series of increasing ethanol concentrations before application of hydrophobic adhesive (group 5). All the bonding procedures were done under simulated pulp pressure. After 24 hours, micro-tensile bond strength test were performed on the specimens. Bonding interfaces were observed under laser scanning confocal microscope (LSCM) after the pulp chamber were filled with a water-soluble fluoroprobe rhodamine B for 3 hours.
  
  
  RESULTS
  Compared with the control group [(38.14 ± 4.97) MPa], bond strengths in group 1 [(21.02 ± 7.23) MPa] and group 2 [(29.64 ± 3.81) MPa] were statistically lower (P > 0.05), while bond strength in group 3 [(38.40 ± 5.03) MPa], group 4 [(37.26 ± 4.68) MPa] and group 5 [(40.12 ± 5.95) MPa] were similar to the control group (P < 0.05). The images taken by LSCM showed that with extension of ethanol-wet time, the deposition of fluorescent dye in hybrid layer and along the dentinal tubules decreased gradually. Especially in group 5, only spare fluorescent dye deposition could be detected in the hybrid layer.
  
  
  CONCLUSIONS
  Dentin saturated with ethanol for more than 2 min before bonding hydrophobic adhesive to dentin could provide favorable bond strength and decreased the micropermeability of bonding interfaces under simulated pulp pressure.
authors.affiliation: Department of Prosthodontics, School of Stomatology, Wuhan University, Wuhan 430079, China.
authors.forename: Dong-ping
authors.initials: DP
authors.lastname: Chen
authors.forename: Dan-dan
authors.initials: DD
authors.lastname: Pei
authors.forename: Ya-ke
authors.initials: YK
authors.lastname: Wang
authors.forename: Cui
authors.initials: C
authors.lastname: Huang
authors.lastname: A-da-lai-ti
authors.forename: Si-ying
authors.initials: SY
authors.lastname: Liu
mesh_terms: D000134:Acid Etching, Dental; D003188:Composite Resins; D001840:Dental Bonding; D003738:Dental Cements; D003743:Dental Enamel; D003786:Dental Pulp Cavity; D003804:Dentin; D017220:Dentin-Bonding Agents; D000431:Ethanol; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008422:Materials Testing; D019279:Resin Cements; D013718:Tensile Strength; D014867:Water
chemical_list: D003188:Composite Resins; D003738:Dental Cements; D017220:Dentin-Bonding Agents; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; D014867:Water; D000431:Ethanol; C041330:Scotchbond