title: Photopolymerization of developmental monomers for dental cationically initiated matrix resins.
abstract: OBJECTIVE
  The objectives were to investigate the structure and selected physical properties of products resulting from the photopolymerization of a binary mixture containing an aliphatic dioxirane, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate (ECHM-ECHC) and a potential expanding monomer, 3,9-bis(oxiranylcyclohexylmethyl)-1,5,7,11-tetraoxaspiro[5.5]undecane (BOCHM-TOSU).
  
  
  METHODS
  Reaction mixtures were irradiated with a dental curing lamp at room temperature. Some reactions were quenched prior to gel point. Oligomeric products were separated from unreacted monomers by column chromatography, and analyzed by NMR. Physical properties of polymeric solids were measured using accepted standard methods. Protonation energies for monomers were calculated using semi-empirical quantum mechanical methods.
  
  
  RESULTS
  Types of oligomers found included poly(ether)s and poly(carbonate)s. Quantum mechanical calculations indicated preferential attack at the more nucleophilic oxaspirocyclic ring sites. For cured solid polymer samples, the elastic modulus was 2.39 +/- 0.24 GPa and the fracture toughness was 0.73 +/- 0.10 MPa m(1/2). These values were similar to those measured for a cured conventional BISGMA/TEGDMA matrix resin.
  
  
  CONCLUSIONS
  The room-temperature photopolymerization of an aliphatic dioxirane and a potential expanding monomer demonstrates the possibility of making cross-linked copolymer resins with improved polymerization shrinkage characteristics for use in dental composites.
authors.affiliation: Department of Oral Biology, School of Pharmacy and Dentistry, University of Missouri-Kansas City, 615 East 25th Street, Kansas City, MO 64108, USA. eickj@umkc.edu
authors.forename: J David
authors.initials: JD
authors.lastname: Eick
authors.forename: Robert E
authors.initials: RE
authors.lastname: Smith
authors.forename: Charles S
authors.initials: CS
authors.lastname: Pinzino
authors.forename: Shiva P
authors.initials: SP
authors.lastname: Kotha
authors.forename: Elisabet L
authors.initials: EL
authors.lastname: Kostoryz
authors.forename: Cecil C
authors.initials: CC
authors.lastname: Chappelow
mesh_terms: D000473:Alkanes / Q000737:chemistry / Q000528:radiation effects; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002412:Cations; D003188:Composite Resins / Q000737:chemistry; D003510:Cyclohexanes / Q000737:chemistry / Q000528:radiation effects; D003764:Dental Materials / Q000737:chemistry* / Q000528:radiation effects; D004548:Elasticity; D004852:Epoxy Compounds / Q000737:chemistry / Q000528:radiation effects; D004853:Epoxy Resins / Q000737:chemistry* / Q000528:radiation effects; D004987:Ethers / Q000737:chemistry / Q000528:radiation effects; D006801:Humans; D008027:Light; D008422:Materials Testing; D011076:Polycarboxylate Cement / Q000737:chemistry / Q000528:radiation effects; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry* / Q000528:radiation effects; D011109:Polymethacrylic Acids / Q000737:chemistry; D013141:Spiro Compounds / Q000737:chemistry / Q000528:radiation effects; D013499:Surface Properties
chemical_list: D000473:Alkanes; D002412:Cations; D003188:Composite Resins; D003510:Cyclohexanes; D003764:Dental Materials; D004852:Epoxy Compounds; D004853:Epoxy Resins; D004987:Ethers; D011076:Polycarboxylate Cement; D011108:Polymers; D011109:Polymethacrylic Acids; D013141:Spiro Compounds; C016269:bisoxirane; C470249:epoxy cyclohexyl methyl-epoxy cyclo-hexane carboxylate; C020946:triethylene glycol dimethacrylate; C061799:dioxirane; C005506:polycarbonate; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; C022884:undecane