title: Effect of the silicone disclosing procedure on the shear bond strength of composite cements to ceramic restorations.
abstract: BACKGROUND
  There is no evidence-based information on how ceramic restorations with an adhesive bond between restoration material and composite cement may be influenced by a silicone disclosing agent.
  
  
  OBJECTIVE
  The aim of this study was to determine the effects of the silicone disclosing procedure on the shear bond strength of composite cements in the luting of industrial sintered and laboratory sintered ceramic restorations.
  
  
  METHODS
  Thirty standardized (15 x 10 x 9 mm) prefabricated ceramic specimens (Groups 1, 3, 5) and 30 standardized (15 x10 x 9 mm) conventionally sintered ceramic specimens (Groups 2, 4, 6) were roughened with sandpaper (800-grit). Each group contained 10 specimens. Groups 3 and 4 were conditioned with hydrofluoric acid and primed with silane solution after the use of a silicone disclosing procedure. Groups 1 and 2 served as the control groups, where no silicone disclosing procedure was performed. Groups 5 and 6 were insulated with glycerine before the silicone disclosing procedure. A glass tube (4.5 mm in diameter) was used to apply a cylinder of dual-polymerized composite cement to the conditioned surfaces. All specimens were submitted to 5000 thermocycles (5 degrees to 55 degrees C) to simulate the in vivo situation. The specimens were subjected to a shear-pull test at a constant crosshead speed of 5 mm/min with a universal testing machine. The comparative shear bond strengths were analyzed by use of Duncan's test (alpha=0.05).
  
  
  RESULTS
  Shear bond strength values for Groups 1 (9.86 +/- 4.97 MPa) and 2 (9.56 +/- 4.47 Mpa) were obtained with no significant differences. Lower but significantly undifferent values were obtained for Groups 3 (7.49 +/- 4.67 MPa) and 4 (7.62 +/- 3.49 MPa) after the use of a silicone disclosing procedure. In Groups 5 (8.21 +/- 4.75 MPa) and 6 (8.22 +/- 3.59 MPa), including insulation with glycerine before the silicone disclosing procedure, no significant differences were obtained.
  
  
  CONCLUSIONS
  Within the limitations of this study, the use of silicone disclosing procedures before conditioning the ceramic surface did not lead to a significant reduction of the shear bond strength between ceramic and composite cement. The ceramic materials used (industrial-sintered versus laboratory-sintered ceramic) had no significant influence on adhesion.
authors.affiliation: School of Dentistry, Department of Operative Dentistry, Johann Wolfgang Goethe University, Frankfurt am Main, Germany. s.szep@em.uni-frankfurt.de
authors.forename: Susanne
authors.initials: S
authors.lastname: Szep
authors.forename: Claudia
authors.initials: C
authors.lastname: Schmid
authors.forename: Paul
authors.initials: P
authors.lastname: Weigl
authors.forename: Lothar
authors.initials: L
authors.lastname: Hahn
authors.forename: Detlef
authors.initials: D
authors.lastname: Heidemann
mesh_terms: D000134:Acid Etching, Dental; D002516:Ceramics / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003793:Dental Restoration, Permanent; D005990:Glycerol / Q000737:chemistry; D006801:Humans; D006858:Hydrofluoric Acid / Q000737:chemistry; D008422:Materials Testing; D019279:Resin Cements / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry; D012828:Silicones / Q000737:chemistry*; D013223:Statistics as Topic; D013314:Stress, Mechanical; D013499:Surface Properties; D013816:Thermodynamics
chemical_list: D003188:Composite Resins; D019279:Resin Cements; D012821:Silanes; D012828:Silicones; D005990:Glycerol; D006858:Hydrofluoric Acid