title: Influence of different drying methods on microtensile bond strength of self-adhesive resin cements to dentin.
abstract: OBJECTIVE
  This study investigated the effect of different drying methods of dentin surface on the bonding efficacy of self-adhesive resin cements (SRCs).
  
  
  METHODS
  Three SRCs (RelyX U200, RU; Maxcem Elite, ME; and BisCem, BC) and one resin-modified glass ionomer cement (RelyX Luting 2, RL) were used. The characteristics of the materials were evaluated using thermogravimetric analysis and surface roughness and contact angle measurements. Human dentin surfaces were finished with 600-grit silicon carbide paper and assigned to three groups according to these drying methods: ethanol dehydration, drying by waiting for 10 s after blot-drying and blot-drying. The four cements were used for luting composite overlays to the dried dentin. After 24 h storage at 37°C and 100% relative humidity, stick-shaped specimens with a cross-sectional area of 0.8 mm(2) were prepared and stressed to failure in tension at a crosshead speed of 0.5 mm/min (n = 27). Failure modes of fractured specimens were assessed by optical and scanning electron microscopy.
  
  
  RESULTS
  RL was the most hydrophilic, followed by BC and ME and then RU. All the luting cements luted to ethanol-dehydrated dentin showed zero bond strengths. For the three SRCs, drying by waiting produced higher microtensile bond strengths than blot-drying. RU showed the best bonding performance in the above two dentin conditions. RL showed significantly higher bond strength in blot-drying condition than in drying-by-waiting (p < 0.001).
  
  
  CONCLUSIONS
  This study suggests that dentin surface moisture has a crucial effect on the bond strength of SRCs.
authors.affiliation: Department of Conservative Dentistry, School of Dentistry, Kyungpook National University , Daegu , Korea.
authors.forename: Young Kyung
authors.initials: YK
authors.lastname: Kim
authors.forename: Bong Ki
authors.initials: BK
authors.lastname: Min
authors.forename: Jun Sik
authors.initials: JS
authors.lastname: Son
authors.forename: Kyo-Han
authors.initials: KH
authors.lastname: Kim
authors.forename: Tae-Yub
authors.initials: TY
authors.lastname: Kwon
mesh_terms: D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003764:Dental Materials / Q000737:chemistry; D003799:Dental Stress Analysis / Q000295:instrumentation; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry; D003890:Desiccation; D000431:Ethanol / Q000737:chemistry; D005899:Glass Ionomer Cements / Q000737:chemistry; D006801:Humans; D006813:Humidity; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D019279:Resin Cements / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength; D013997:Time Factors; D017155:Wettability
chemical_list: C542562:BisCem cement; D003188:Composite Resins; D003764:Dental Materials; D017220:Dentin-Bonding Agents; D005899:Glass Ionomer Cements; C515955:Maxcem; C587242:RelyX U200; D019279:Resin Cements; D012997:Solvents; C084550:Vitremer; D000431:Ethanol
keywords: dentin wetness; microtensile bond strength; self-adhesive resin cement; surface energy parameters