Study On Mechanical Properties And Surface Candida Adhesion Of Pure Titanium Stents With Different Processing Techniques

Objective:By comparing the mechanical properties and surface candida adhesion experiments of pure titanium specimens made by traditional processing methods of embedded casting,CAD/CAM numerical control milling,and 3D printing,the mechanical properties and surface rosary of pure titanium stents by different processing techniques The impact of bacterial adhesion provides a reference for the manufacturing process of clinically selected pure titanium stents.Method:The experiment is divided into three groups:traditional embedding casting,CAD/CAM CNC milling,and 3D printing.Through the traditional embedding casting,CAD/CAM CNC milling,and 3D printing,three different processes are used to produce 20*10*1mm pure titanium with the same specifications.The proportion of the porosity inside the test piece for X-ray flaw detection;use a universal testing machine to test the mechanical strength of the test piece;after processing the pure titanium test pieces made by the three processes in the same way,they are separately polished and In two stages of fine grinding,the surface is subjected to electron microscopy scanning and roughness detection;the pure titanium specimens of the three processes of general grinding and fine grinding of the two surface states are placed in the medium inoculated with Candida albicans 18-24 hours,detect the adhesion of Candida on the surface by microplate reader.Quantitatively compare the values of the obtained results,and through statistical analysis,compare the differences of three pure titanium specimens made by different processing techniques.Results:1 X-ray inspection found that some of the specimens produced by traditional embedding and casting had pores inside.The average area of pores measured by the case analysis image system was 0.23mm~2/piece.The internal structure of the specimens produced by CNC milling and 3D printing was precise without pores.2 The CNC milling group has the highest bending strength,the traditional embedded casting group has the smallest,and the difference between the three is statistically significant(P<0.05).In the shear strength test,the numerical control milling group had the highest shear strength,which was statistically significant compared with the other two groups(P<0.05),and the traditional embedded casting had no statistical significance compared with the 3D printing group(P?0.05).3 After sem general grinding,the surface of CNC milling group is compact and clear,3D printing group surface has similar mesh structure,the surface of traditional embedded casting group is uneven and has no regular grain;After fine grinding,the surface of CNC milling and 3D printing group is smooth and smooth,and the surface of traditional embedded casting group appears scattered in pores.4 The surface roughness detection is generally the smallest in the CNC milling group after grinding and the largest in 3D printing.The difference between the three is statistically significant(P<0.05);after fine grinding,the surface roughness of the CNC milling group has no statistical significance(P>0.05),3D printing and traditional embedding casting group have statistically significant changes(P<0.05),the difference between the three is statistically significant(P<0.05).5 Detection by microplate reader,the value-added level of bacteria in CNC milling group is generally lower after grinding(P<0.05),the value-added level of bacteria in 3D printing group is the highest(P<0.05),the difference between the three is statistically significant(P<0.05).Compared with the other two groups,the value-added level of bacteria in the 3D printing group after fine polishing was statistically lowest(P<0.05),and there was no statistically significant difference in the adhesion level of bacteria in the traditional embedded casting and CNC milling groups(P>0.05).In conclusion:The internal structure of the specimen made CAD/CAM CNC milling and 3 D printing is dense,no porosity,and the mechanical properties are better than the traditional embedded casting,and CNC milling is better than the 3D printing.After conventional grinding,the surface roughness of the CNC milling specimens was the smallest,and the candida attachment experiment also showed that the proliferation level was the lowest,and the tissue surface of clinical denture was made without fine grinding,combined with the mechanical properties test results,CAD/CAM CNC milling process was more suitable for the fabrication of removable local denture pure titanium scaffolds.