ABSTRACT
Objective @# A titanium personalized orthodontic bracket is designed and manufactured using the technology of computed tomography (CT), computer aided design (CAD), finite element analysis (FEA), and selective laser melting (SLM) to well match the patient tooth so as to realize mold-free manufacturing. @*Methods@#A model of a titanium personalized orthodontic bracket which is built by CT scanning machine and Pro/E software, is imported into Ansys software to carry out finite element simulation analysis with nonlinear contact method. Then, the titanium personalized orthodontic bracket is proposed after the model data above is imported to SLM molding equipment via titanium powder melted with layer by layer using a high-speed scanning galvanometer. @*Results @#The maximum equivalent stress of the titanium personalized orthodontic bracket is distributed uniformly and reasonably, the titanium personalized orthodontic bracket formed by SLM molding equipment can provide high accuracy and there is a high similarity between the bottom of the orthodontic bracket and the tooth surface shape.@*Conclusion @#The combination of CT, CAD, FEA, SLM technology can fulfill model-free manufacturing of the personalized orthodontic bracket and thus shorten the manufacturing cycle.
ABSTRACT
Objective:To establish the quality control for Yangxueyin oral liquids. Methods:TLC was applied to identify Angeli-cae Sinensis Radix and Fructus Ziziphi Jujubae. The content of astragaloside A in Yangxueyin oral liquids was determined by HPLC-ELSD. A Luna C18(250 mm ×4.6 mm,5 μm)column was used, the mobile phase was acetonitrile-water (38∶62)with the flow rate of 0. 8 ml·min-1 , and the column temperature was 40℃. The temperature of the drift tube was 85℃, and the flow rate of the carrier air was 2.0 L·min-1. Results: The linear range of astragaloside A was 0.522-4.176 μg(r =0.999 8). The average recovery was 97. 9% with RSD of 1. 03% (n=6). Conclusion:The method is convenient, sensitive and accurate, which can be used in the quality control of Yangxueyin oral liquids.