title: Development of a dental model hardener.
abstract: The paper presents a novel method of strengthening dental gypsum materials by infiltrating with a low-viscosity autopolymerising monomer. Gypsum specimens were infiltrated with diluted butyl-cyanoacrylate monomer at different concentrations. Nanoindentation was employed to measure their hardness and elastic modulus. A standard single-edge-notched beam (SENB) method was used to measure fracture toughness. Biaxial strength was measured using a universal test machine with a piston-on-ring jig. Scanning Electron Microscopy (SEM) and affiliated energy dispersive X-ray spectroscopy (EDX) were used to observe the fracture topography and the depth of infiltration. Infiltration and autopolymerisation of the cyanoacrylate improved the biaxial strength and fracture toughness of the gypsum by around 39% and around 30%, respectively. The hardness and elastic modulus for the treated specimens were also higher, albeit slightly. The proposed method provides a convenient way to strengthen and repair dental gypsum models in situ.
authors.affiliation: Sir John Walsh Research Institute, School of Dentistry, University of Otago, Dunedin, New Zealand. lihong.he@otago.ac.nz
authors.forename: Li-Hong
authors.initials: LH
authors.lastname: He
authors.forename: Ludwig Jansen
authors.initials: LJ
authors.lastname: van Vuuren
mesh_terms: D002133:Calcium Sulfate / Q000737:chemistry*; D003799:Dental Stress Analysis / Q000295:instrumentation; D004058:Diffusion; D055119:Elastic Modulus; D004577:Electron Probe Microanalysis; D004659:Enbucrilate / Q000737:chemistry*; D006244:Hardness; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D003765:Models, Dental; D058105:Polymerization; D013052:Spectrometry, X-Ray Emission; D013314:Stress, Mechanical; D014783:Viscosity
chemical_list: D004659:Enbucrilate; D002133:Calcium Sulfate