title: Comparison of four silane primers and an isocyanate primer for bonding of tri-n-butylborane resin to a leucite-reinforced glass ceramic.
abstract: OBJECTIVE
  The purpose of the present study was to compare the effectiveness of an isocyanate monomer and four different silane monomers as primer components for bonding a leucite-reinforced glass ceramic (GN-Ceram Block).
  
  
  METHODS
  Four different methyl-methacrylate based primers, each with three different concentrations (1, 4, or 16wt%) of 2-methacryloxyethylisocyanate (MOI), 3-methacryloxypropylmethyldimethoxysilane (MDS), 3-methacryloxypropyltrimethoxysilane (MTS), and 3-acryloxypropyltrimethoxysilane (ATS) were prepared. A commercially available silane primer (ESPE™Sil) was also used as a control. The GN-Ceram Block specimen was ground with silicon carbide paper, rinsed, primed, and then bonded to a resin composite disk using a tri-n-butylborane-initiated self-curing luting agent. After 24-h immersion in water, the shear bond strengths were determined.
  
  
  RESULTS
  The highest level of bond strength was obtained with 4wt% MTS (45.2 MPa) and 4wt% ATS (38.7 MPa), followed by 4wt% MOI (29.8 MPa), ESPE™Sil (28.1 MPa), and 4wt% MDS (27.9 MPa). For each MTS, ATS, MOI, and MDS, the bond strengths for concentrations of 4wt% and 16wt% were not significantly different. No significant differences were found between 4wt% ATS, 4wt% MOI, ESPE™Sil, and 4wt% MDS. The use of any of these primers led to a significant increase in bond strength compared to an unprimed control (13.8 MPa).
  
  
  CONCLUSIONS
  The type and concentration of monomers dissolved in the primer influence the bond strength between a tri-n-butylborane resin and a leucite-reinforced glass ceramic GN-Ceram Block. The effectiveness of MOI was found to be comparable to that of MDS, ATS, and ESPE™Sil, but inferior to that of MTS.
authors.affiliation: Department of Applied Prosthodontics, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan. yohsuke@nagasaki-u.ac.jp
authors.forename: Yohsuke
authors.initials: Y
authors.lastname: Taira
authors.forename: Miyuki
authors.initials: M
authors.lastname: Sakai
authors.forename: Kohyoh
authors.initials: K
authors.lastname: Soeno
authors.forename: Takashi
authors.initials: T
authors.lastname: Sawase
mesh_terms: D000538:Aluminum Silicates; D001896:Boron Compounds; D002516:Ceramics; D001840:Dental Bonding / Q000379:methods*; D017953:Isocyanates; D020366:Methylmethacrylate; D012117:Resins, Synthetic; D012821:Silanes
chemical_list: D000538:Aluminum Silicates; D001896:Boron Compounds; D017953:Isocyanates; D012117:Resins, Synthetic; D012821:Silanes; C009523:tri-n-butylborane; C078519:leucite; D020366:Methylmethacrylate; C023506:Glass ceramics