Computer aided design and manufacturing of the framework of PFM fixed bridge

In this paper we develop an original dental CAD/CAM system for design and manufacture the framework of PFM (porcelain fused to metal) fixed bridge in computer. Take example for the missing of the mandibular first molar, firstly, we use ATOS II 3D scanner to measure the 3D data of the abutment teeth which is used to design the coping crowns. Secondly, a relevant standard bridge is selected from the standard bridges database and deformed based on the characteristic of the patient. Then it's set to the correct position between the coping crowns automatically based on the constraint lines and faces. Finally, two connectors are designed to connect the coping crowns and the bridge based on the cutting area. The final product is milled by a 4-axis NC milling machine. After examined, the framework of PFM fixed bridge fits the abutment teeth very well. The intensity of the connectors and the precision of the whole model all tally with clinically demand. According to the final result, the method of design and manufacturing the framework of PFM fixed bridge using CAD/CAM technology is feasible, efficient and precise. It is also an important part of the homemade dental CAD/CAM system