title: [Directionality of shear bond strength of resin adhesives on human enamel].
abstract: OBJECTIVE
  To investigate the relationship between the shear bond strength of resin adhesion on the enamel of human teeth and loading direction.
  
  
  METHODS
  Two kinds of dental resin adhesives [Group A (Clearfil SE BOND) and Group B (Prime&Bond NT)] were used to bond their responding resin composites to the enamel of human teeth respectively. The shear tests were performed from four directions: root apex direction, occlusion direction, mesial direction, and distal direction.
  
  
  RESULTS
  The shear bond strength of the two resin adhesives on the enamel behaved in the same way, which was the root apex direction [(44.38 +/- 3.68) Pa and (45.50 +/- 2.88) Pa] > mesial direction [(37.81 +/- 7.56) Pa and (40.15 +/- 2.59) Pa] and distal direction [(35.71 +/- 3.34) Pa and (35.75 +/- 4.15) Pa] > occlusion direction [(29.19 +/- 3.75) Pa and (33.44 +/- 3.79) Pa], respectively. A significantly statistical difference in the shear bond strength values was found between the root apex direction and the occlusion direction (P < 0.05), and there was no statistical significant difference between the mesial and distal directions (P > 0.05).
  
  
  CONCLUSIONS
  The shear bond strength between the human tooth enamel and the dental resin adhesives is related to the direction of the shearing force.
authors.affiliation: Dental Material Laboratory, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Liu
authors.forename: Rui
authors.initials: R
authors.lastname: Zheng
authors.forename: Gang
authors.initials: G
authors.lastname: Zheng
mesh_terms: D001840:Dental Bonding; D003743:Dental Enamel; D006801:Humans; D066298:In Vitro Techniques; D019279:Resin Cements; D033081:Shear Strength
chemical_list: C438313:Clearfil SE Bond; D019279:Resin Cements