Design Of Fixed Partial Denture For Dental CAD/CAM System And Three-dimensional Finite Element Analysis Of The Connector

Objective: This study was to explore a CAD method for constructing posterior bridge with reverse engineering (RE) software and to develop CAD software for our own country. The stress of the connector of the bridge was analyzed to find the best design of the connector. Methods: 1.A standard dentition model with right mandibular fist molar absent was scanned with 3D mechanical scanner. Cloud data of the model was got to reconstruct 3D model of the maxillary and mandibular dental arch. Bridges were designed with standard tooth database we had built. 2. 3D models were constituted with different kinds of connectors, and the stress of the connector under different loads was compared. Results: 1.The exterior surface was constituted on the basis of the abutment before preparing and the interior surface after preparing. The design of the retainer was finished by connecting the exterior and interior surface. The standard tooth data was adjusted to get the pontic. Check the occlusal surface by simulating the bite of the maxillary and mandibular dental arch after connecting the retainer and pontic. The design of the partial fixed denture of CAD/CAM was completely finished. Bridge designed with CAD technique showed smooth and continuous contours. The occlusal and proximal contacts of bridge met physiologic demands. 2. Different kinds of connector suffered differently. The connector area of model 3 was bigger than model 2 and model 1, while the stress was lessthan model 2 and 1 after being loaded. When we used the arc transition surface, we can find that: when the semidiameter was 0.25mm, the stress of the connector didn' t change distinctly. When the semidiameter was 0.4mm, 0.8mm, 1.0mm or 1.25mm, the stress of the connector reduced. Conclusions: 1. It is a feasible method to develop a CAD software for the bridge fabrication based on RE software. 2. We may augment the area of the connector to reduce the stress if the denture can satisfy the functional and aesthetic request. The connector should be designed with the arc transition surface which semidiameter was 0.8mm and 1.0mm to reduce the stress.