title: [Influence of time on shear strength using resin cements].
abstract: OBJECTIVE
  To compare the shear bond strength of different composite resin cement systems at different time intervals.
  
  
  METHODS
  48 healthy non-carious human molars were selected in the study. The samples were divided into two groups, 24 in each group. (1) RelyX unicem was used on bonding, (2) Variolink 2 was used on bonding. All specimens were stored in water at 37 degrees C for 2 hours, 24 hours and 1 week. 8 specimens in each group were stressed in shear until failure. Statistical analysis was performed with SPSS11.0 software package. Debonged surface was examined under light microscope.
  
  
  RESULTS
  Shear bond strengths of two resin cements showed a significant increase as time went (P<0.05). The failure involved the adhesive/dentin interfaces.
  
  
  CONCLUSIONS
  Time can influence the shear bond strength using different composite resin cement systems. Supported by Shanghai Leading Academic Discipline Project (Grant No.T0202).
authors.affiliation: Department of Prosthodontics, College of Stomatology, Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, China.
authors.forename: Wei-min
authors.initials: WM
authors.lastname: Weng
authors.forename: Xiu-yin
authors.initials: XY
authors.lastname: Zhang
authors.forename: Fu-qiang
authors.initials: FQ
authors.lastname: Zhang
mesh_terms: D002681:China; D001840:Dental Bonding; D003738:Dental Cements; D003804:Dentin; D017220:Dentin-Bonding Agents; D005899:Glass Ionomer Cements; D019279:Resin Cements; D033081:Shear Strength
chemical_list: D003738:Dental Cements; D017220:Dentin-Bonding Agents; D005899:Glass Ionomer Cements; D019279:Resin Cements; C103502:Variolink