title: [Effect of polymerization-shrinkage of different resin composites curing by two different light curing units].
abstract: OBJECTIVE
  To investigate the effect of light-emitting diode (LED) light curing unit (LCU) and quartz-tungsten (QTH) LCU on the polymerization-shrinkage of different resin composites.
  
  
  METHODS
  Three composites Z100, Z250, AP-X were irradiated by QTH LCU and LED LCU. Polymerization-shrinkage of 50s and 400s after the composites curing were measured by 3D-profile measuring apparatus by phase-shifted projected grating.The polymerization-shrinkage of LED and QTH curing composites were analysed by SPSS12.0 software package of one-way ANOVA.
  
  
  RESULTS
  At 50s curing and 400s curing period, the polymerization- shrinkage of Z100, Z250 resin was different by QTH LCU and LED LCU curing, the polymerization-shrinkage by LED LCU curing was less than that by QTH LCU (P < 0.05); the polymerization-shrinkage of AP-X was not statistically different by QTH LCU and LED LCU curing (P > 0.05). CONCLUSUINS: The polymerization-shrinkage of Z100,Z250 resin is statistically less cured by LED LCU than QTH; the polymerization-shrinkage of AP-X resin is not statistically different cured by QTH LCU and LED LCU. Supported by Research Fund of Science and Technology Commission of Shanghai Municipality (08DZ2271100).
authors: Department of Prosthodontics, Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, China. dengxl118@163.com
authors: Xiao-lin
authors: XL
authors: Deng
authors: Bao-wei
authors: BW
authors: Zhang
authors: Peng
authors: P
authors: Lu
mesh_terms: D003188:Composite Resins; D055117:Curing Lights, Dental; D006244:Hardness; D008422:Materials Testing; D008689:Methacrylates; D058105:Polymerization
chemical_list: C112828:Clearfil AP-X; D003188:Composite Resins; D008689:Methacrylates