Experimental Study On Fabrication Of Titanium Crown,Fixed Bridge And Base Of Complete Denture With Laser Solid Forming Technology

Titanium and titanium alloy is perfect metal material in dental prosthesis for its outstanding biochemical performance and suitable mechanical property. But it's main processing way is still casting, and could not be satisfied with the needs of the titanium restoration making, which now have been high material performance, automatic and rapid manufacture. Also for its high melting point, active chemical property in high temperature, titanium and titanium alloy is easy to combine with elements such as oxygen, nitrogen and carbon, these factors make it difficult casting, and affect its applications in prosthodontics. With the development of computer and industry technology, new techniques have continuously emerged, especially with the applications of reverse technique and numerical control, CAD/CAM has begun to been used in titanium restorations' fabrication, and is hoped to be the tendency of titanium prosthesis making.In reverse measurement of CAD/CAM technology, neither mechanical contact method nor optical measurement can meet the complex and high precision modeling request in stomatognathic system. The data collected by measurement system of cutting and scanning layer-by-layer, will not belimited by complex model shape and can be obtained in high precision, so the new method will support new ideas for stomatognathic system Three-dimensional reconstruct.Laser solid forming technology is a new technique combined with rapid prototype and laser cladding techniques. It can achieve computer assistant automatic processing with computer designed restoration data. This technique also can be prone to fabricate titanium alloy difficult in casting by conventional manufacture, using increasing material method can overcome the flaws of now used losing material cutting method.In this study, digital dentognathic model was reconstructed with a measurement system by cutting and scanning layer-by-layer, a computer assistant program was developed base on SURFACER software, and thus clinical crown , fixed bridge and a palatal plate of upper complete denture were designed; The new laser solid forming technology was researched to form titanium prosthesis by direct powder deposition, then some preliminary tests for physical, chemical, biological and mechanical property were made to base a foundation for using this new titanium process technology in prosthodontics.Conclusions presented in this paper can be summarized as follows:1. Improved measurement system of cutting and scanning layer-by-layer with simple and convenient structure has stronger commonability and lower measurement cost, there is no blind area of data at the time of modeling, the form of opposite tooth and occlusion can also be obtained at the same time, it will effectively solve the problem of the digitization shift of patients' occlusion situation in CAD/CAM study.2. The system makes a repeated location accurately, the measurement to the picture is steady, but there is geometry distortion. So it is proposed not to obtain sectional picture of the too big range once. The system has better stabilities to the reconstruction of the model and data of measurements has higher precision.3. The auxiliarily program developed in the experiment has succinct and...