title: Development of high-toughness resin for dental applications.
abstract: OBJECTIVE
  The purpose of this study was to develop a heat-cured resin with improved toughness. Polyurethane dimethacrylate (PUDMA) with hard and soft segments in the chemical structure was synthesized using polyurethane diisocyanate and 2-HEMA.
  
  
  METHODS
  The bulk polymerization of PUDMA, Bis-GMA, TEGDMA and MMA was carried out in a glass tube with 0.5 wt% of BPO at 60 degrees C for 24 h and 110 degrees C for 3 h. The physical and mechanical properties of these polymers were measured, i.e., the polymerization shrinkage, water sorption, transverse strength, modulus of elasticity, deflection and Knoop hardness of these polymerized methacrylates were determined.
  
  
  RESULTS
  The volume shrinkage and the water sorption values of PUDMA were lower than those of Bis-GMA. The transverse strength and the modulus of elasticity of PUDMA were close to those of PMMA. The deflection of PUDMA, as determined by a bending test, was higher than any of the other cured resins tested.
  
  
  CONCLUSIONS
  These results suggest that PUDMA is an excellent toughened polymer. The fracture toughness of PUDMA is sufficient for crown and bridge resins and dental composites.
mesh_terms: D000180:Acrylic Resins / Q000138:chemical synthesis / Q000737:chemistry*; D000704:Analysis of Variance; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003764:Dental Materials / Q000138:chemical synthesis / Q000737:chemistry*; D004548:Elasticity; D006244:Hardness; D009682:Magnetic Resonance Spectroscopy; D008689:Methacrylates / Q000138:chemical synthesis* / Q000737:chemistry*; D020366:Methylmethacrylate; D008768:Methylmethacrylates / Q000737:chemistry; D008970:Molecular Weight; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D011140:Polyurethanes / Q000138:chemical synthesis* / Q000737:chemistry*; D012031:Refractometry; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: D000180:Acrylic Resins; D003764:Dental Materials; D008689:Methacrylates; D008768:Methylmethacrylates; D011109:Polymethacrylic Acids; D011140:Polyurethanes; C097103:polyurethane dimethacrylate; C020946:triethylene glycol dimethacrylate; D020366:Methylmethacrylate; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate