title: [A comparative study of mechanical properties of commercialized dental thermoplastic materials].
abstract: OBJECTIVE
  To compare the mechanical properties of different dental optimal material selection for orthodontic appliance.
  
  
  METHODS
  Four commercialized thermoplastic products under different test conditions, and provide the suggestion of thermoplastic products were tested. The tear strength, elongation at break and stress relaxation of these materials were measured under different test conditions.
  
  
  RESULTS
  The tear strength declined after thermoforming, and rose again after 2 weeks of distilled water immersion. The elongation at break rose after thermoforming, and declined after 2 weeks of distilled water immersion. No significant changes were observed for brand A under different test conditions. Brand A showed the slowest stress relaxation of 0.0148 N/s.
  
  
  CONCLUSIONS
  The mechanical properties of thermoplastic materials were influenced by environmental factors. Brand A exhibited optimal comprehensive properties.
authors.affiliation: Department of Orthodontics, Capital Medical University School of Stomatology, Beijing, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Zhang
authors.forename: Dong-yu
authors.initials: DY
authors.lastname: Fang
authors.forename: Yu-xing
authors.initials: YX
authors.lastname: Bai
authors.forename: Xue-jia
authors.initials: XJ
authors.lastname: Ding
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000704:Analysis of Variance; D003764:Dental Materials / Q000737:chemistry*; D006358:Hot Temperature; D008422:Materials Testing; D009967:Orthodontic Appliances; D011095:Polyethylenes / Q000737:chemistry*; D011145:Polyvinyls / Q000737:chemistry*; D033081:Shear Strength; D013314:Stress, Mechanical
chemical_list: D003764:Dental Materials; D011095:Polyethylenes; D011145:Polyvinyls; C477722:polyethylene-polyvinylacetate copolymer