title: [Comparasion of clinical and technical operating time of full-crown restorations between traditional and Triple-tray impression techniques].
abstract: OBJECTIVE
  To compare the difference of clinical and technical processes of full-crown restorations by using traditional and Triple-tray impression  techniques, consumed materials and time estimated in every procedure of these two methods.
  
  
  METHODS
  Four veteran clinicians were selected to carry  out full-crown restorative treatment for 124 patients (130 crowns). From one impression, dentists could make casts of prepared teeth and the opposing  dentition and register the interocclusal relationship.After tooth preparation,Impregum Penta polyether impression was fabricated for 76 cases(80 crowns) by Triple-tray method and 48 cases (50 crowns)by conventional method. During the whole processes, the consumption of impression materials and  plaster, the time of fitting on the articulator, manufacturing procedure and try-in in clinical practice were recorded. The differences of material and time  consumption in every procedure of these two methods were evaluated by Independent-Samples t test.
  
  
  RESULTS
  The consumption of impression  materials and plaster of Triple-tray impression technique was significantly less than that of traditional impression technique(P<0.01), and average time  in every procedure of Triple-tray impression technique was remarkablely reduced compared with that of the traditional impression technique (P<0.01).   Triple-tray impression technique reduces operating costs and the possibility of error.
  
  
  CONCLUSIONS
  Compared with traditional impression technique,  Triple-tray impression technique could reduce the consumption of time and materials in clinical and technical processes.
authors.affiliation: Dental Laboratory Center, Peking University School and Hospital of Stomatology, Beijing 100081,China.
authors.forename: Yan-xi
authors.initials: YX
authors.lastname: Xing
authors.forename: Dong
authors.initials: D
authors.lastname: Peng
authors.forename: Yu-guang
authors.initials: YG
authors.lastname: Wang
mesh_terms: D003442:Crowns; D003760:Dental Impression Materials / Q000737:chemistry*; D003761:Dental Impression Technique; D006801:Humans; D003765:Models, Dental; D013997:Time Factors
chemical_list: D003760:Dental Impression Materials