title: Silicone Disclosing Material used after Ceramic Surface Treatment Reduces Bond Strength.
abstract: OBJECTIVE
  To evaluate the effect of a silicone disclosing procedure performed at different timepoints on the shear bond strength (SBS) of cements (self-adhesive composite cement, self-etch composite cement, resin-reinforced glass-ionomer cement) to different substrates (zirconia, lithium disilicate, bovine dentin).
  
  
  METHODS
  The substrate/cement combinations were assigned to two groups (n = 15) according to the timepoint, at which the vinyl polyether silicone disclosing agent was applied: after (experimental groups, EXP) or before (control groups, CTRL) specific micromechanical treatments of the substrate surface. To increase standardization, the cements were applied into rubber rings (2.2 mm diameter x 1.0 mm thickness) positioned on the substrate surface. After luting procedures, all specimens were stored in 37°C distilled water for 24 h, then subjected to SBS testing using a wire loop of 0.2 mm diameter at a crosshead speed of 1 mm/min until failure. Failure analysis was performed for all tested specimens. SBS data were submitted to Weibull analysis.
  
  
  RESULTS
  The silicone disclosing procedure performed after micromechanical surface treatment reduced the characteristic shear bond strength to zirconia and lithium disilicate when compared to CTRL. However, for dentin specimens, there was no significant difference between CTRL and EXP for any of the cements investigated. Failure analysis showed a predominance of interfacial failures.
  
  
  CONCLUSIONS
  The silicone disclosing procedure performed after the micromechanical treatment of ceramic surfaces negatively affected the cement bond strength. Therefore, after using it to check the fit of a prosthesis, clinicians should carefully clean the ceramic surface.
authors.forename: Sara
authors.initials: S
authors.lastname: Fraga
authors.forename: Sara Cioccari
authors.initials: SC
authors.lastname: Oliveira
authors.forename: Gabriel Kalil Rocha
authors.initials: GK
authors.lastname: Pereira
authors.forename: Pieter
authors.initials: P
authors.lastname: Beekman
authors.forename: Marília Pivetta
authors.initials: MP
authors.lastname: Rippe
authors.forename: Cornelis J
authors.initials: CJ
authors.lastname: Kleverlaan
mesh_terms: D001840:Dental Bonding; D003738:Dental Cements; D003804:Dentin; D008422:Materials Testing; D033081:Shear Strength; D012828:Silicones
chemical_list: D003738:Dental Cements; D012828:Silicones