Abstract: Objective ① To evaluate whether manufacturing edentulous jaw individual tray by 3D printing can effectively reduce the clinical chair side time compared with traditional method. ② To compare the fixation strength and changes between alginate impression and the impression surface of trays ［3D printing tray(Polylactic acid/PLA), traditional tray(acrylic resin and light-cured resin)］ after dealt with different ways. Methods ① Select ten models of edentulate patients, then screen maxillary(A) and mandible(B)(n=10). Record the chair side time of fabricating individual trays in 3D and traditional ways. ② Handle the trays by wontfix, the tray binder and punching, measure the fixation strength between the impression surface of 3D printing and traditional trays in the above three conditions and the alginate impression. Results ① The chair side time of 3D printing trays were 34.37 min(A) and 28.19 min(B), while traditional trays were 64.95 min(A) and 63.94 min(B). 3D printing tray cost less time than traditional tray（P<0.05）. ② The trays dealt with tray binder obtained best fixation strength in 3D printing group, which was 2.31 N/cm(ANOVA Factorial design P<0.01). Conclusion ① Compared with traditional tray, 3D printing tray can reduce the chair time effectively. ② 3D printing tray has nice fixation strength, and we can improve the fixation strength by punching or surface tray adhesive,the latter having more obvious effect.

Key words: Rapid prototyping, 3d printing technology, Toothless jaw individual tray, Chair side time, Fixation strength