title: Tris(trimethylsilyl)silane as a co-initiator for dental adhesive: Photo-polymerization kinetics and dynamic mechanical property.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the polymerization behavior of a model dentin adhesive with tris(trimethylsilyl)silane (TTMSS) as a co-initiator, and to investigate the polymerization kinetics and mechanical properties of copolymers in dry and wet conditions.
  
  
  METHODS
  A co-monomer mixture based on HEMA/BisGMA (45/55, w/w) was used as a model dentin adhesive. The photoinitiator system included camphorquinone (CQ) as the photosensitizer and the co-initiator was ethyl-4-(dimethylamino) benzoate (EDMAB) or TTMSS. Iodonium salt, diphenyliodonium hexafluorophosphate (DPIHP) serving as a catalyst, was selectively added into the adhesive formulations. The control and the experimental formulations were characterized with regard to the degree of conversion (DC) and dynamic mechanical properties under dry and wet conditions.
  
  
  RESULTS
  In two-component photoinitiator system (CQ/TTMSS), with an increase of TTMSS concentration, the polymerization rate and DC of CC double bond increased, and showed a dependence on the irradiation time and curing light intensity. The copolymers that contained the three-component photoinitiator system (CQ/TTMSS/DPIHP) showed similar dynamic mechanical properties, under both dry and wet conditions, to the EDMAB-containing system.
  
  
  CONCLUSIONS
  The DC of formulations using TTMSS as co-initiator showed a strong dependence on irradiation time. With the addition of TTMSS, the maximum polymerization rate can be adjusted and the network structure became more homogenous. The results indicated that the TTMSS could be used as a substitute for amine-type co-initiator in visible-light induced free radical polymerization of methacrylate-based dentin adhesives.
authors.affiliation: University of Kansas, Bioengineering Research Center, 1530W. 15th Street, Lawrence, KS 66045-7609, USA.
authors.forename: Linyong
authors.initials: L
authors.lastname: Song
authors.affiliation: University of Kansas, Bioengineering Research Center, 1530W. 15th Street, Lawrence, KS 66045-7609, USA. Electronic address: yeq@ku.edu.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Ye
authors.affiliation: University of Kansas, Bioengineering Research Center, 1530W. 15th Street, Lawrence, KS 66045-7609, USA.
authors.forename: Xueping
authors.initials: X
authors.lastname: Ge
authors.affiliation: Department of Civil, Environmental and Architectural Engineering, University of Kansas, 1530W. 15th Street, Lawrence, KS 66045-7609, USA.
authors.forename: Anil
authors.initials: A
authors.lastname: Misra
authors.affiliation: University of Kansas, Bioengineering Research Center, 1530W. 15th Street, Lawrence, KS 66045-7609, USA; Department of Mechanical Engineering, University of Kansas, 1530W. 15th Street, Lawrence, KS 66045-7609, USA. Electronic address: pspencer@ku.edu.
authors.forename: Paulette
authors.initials: P
authors.lastname: Spencer
mesh_terms: D001713:Biphenyl Compounds / Q000737:chemistry; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002164:Camphor / Q000031:analogs & derivatives / Q000737:chemistry; D003738:Dental Cements / Q000737:chemistry*; D007455:Iodine / Q000737:chemistry; D007700:Kinetics; D055115:Light-Curing of Dental Adhesives; D009861:Onium Compounds / Q000737:chemistry; D058567:Photoinitiators, Dental / Q000737:chemistry*; D058105:Polymerization; D012821:Silanes / Q000737:chemistry*
chemical_list: D001713:Biphenyl Compounds; D003738:Dental Cements; D009861:Onium Compounds; D058567:Photoinitiators, Dental; D012821:Silanes; C510691:tris(trimethylsilyl)silane; C031291:diphenyliodonium; D017438:Bisphenol A-Glycidyl Methacrylate; D002164:Camphor; D007455:Iodine; C553149:camphorquinone
keywords: Co-initiator; Dental adhesive; Dynamic mechanical analysis; Fourier transform infrared; Polymerization kinetic; Silane