title: Microshear bonding effectiveness of different dentin regions.
abstract: OBJECTIVE
  The aim of this in vitro study was to evaluate the influence of dentin surfaces with different tubule orientation on bond strength of a multimode adhesive system.
  
  
  METHODS
  Twenty human molars were selected and prepared in different ways in order to produce different dentin regions. The teeth were randomized (n = 5) according to the application modes of a multimode adhesive system (etch-and-rinse and self-etching) and to the dentin region (occlusal and proximal - 1.5 mm depth from dentinoenamel junction). Cylindrical restorations were performed on dentin with a starch tube. The samples remained immersed in distilled water for 24 h and the microshear bond strength (μSBS) test was performed. The μSBS values were expressed in MPa and analyzed with ANOVA and Tukey's test (P < 0.05).
  
  
  RESULTS
  There was no significant difference in the bond strength values between the application modes of the adhesive system (P = 0.19); however, the dentin regions (P < 0.05) significantly affected the μSBS. The proximal dentin presented higher bond strength values than occlusal dentin.
  
  
  CONCLUSIONS
  The dentin surfaces with different tubule orientation influenced the bonding effectiveness of the adhesive system tested.
authors.forename: Anelise F
authors.initials: AF
authors.lastname: Montagner
authors.forename: Marcos P M
authors.initials: MP
authors.lastname: Carvalho
authors.affiliation: Department of Restorative Dentistry, Federal University of Santa Maria, Santa Maria, RS, Brazil.
authors.forename: Alexandre H
authors.initials: AH
authors.lastname: Susin
mesh_terms: D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding / Q000379:methods; D003764:Dental Materials / Q000737:chemistry; D003799:Dental Stress Analysis; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing; D008963:Molar; D011897:Random Allocation; D033081:Shear Strength; D013499:Surface Properties
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D017220:Dentin-Bonding Agents