A Preliminary Application On The Manufacture Of Clinical Removable Partial Denture Framework Using CAD/CAM

Computer-aided design and computer-aided manufacture has been widely used in industrial production, construction design, quality objects of calculation, and other fields. dentition defect is a common disease in oral clinic. Since the france scientist Duret introduced the CAD/CAM technique into dentistry in 1985, all over the world people has developed dozens of oral CAD / CAM systems of fixed denture. However, CAD / CAM system for RPD because of its complex and changeable is still in the study. Some scholars have reported their study on the standard plaster model. Some correlate experimentation was evolved in our country by lu peijun at al. But their removable partial denture framework was not deployed in clinic. Our study is to find a way for the computer aided design and manufacture of removable partial denture for clinical cases, which is useful for the development of the RPD professional CAD / CAM software. It made a foundation of the using CAD / CAM technique for clinical RPD framework.Part I Treatment and Establishment of 3-D digital casts for clinical cases with dentition defectsMaterials and methods: Found 3-D information of maxillary and mandible dental casts of clinical patients with partially edentulous dentition via grating projection scanner.Results:Computerized 3-D maxillary and mandible models with correct relationship in patients with partially edentulous dentition were established. By computer, the 3-D models could be rotated, enlarged and shrunk in any direction, establishing preliminarily the database for 3-D maxillary and mandible dental casts of clinical patients with dentition defects.Conclusion: The establishment of the database for 3-D maxillary and mandible dental casts of patients with dentition defects made a foundation for the computer-aided design of RPD.Part II Computer aided design of removable partial denture framework for clinical casesMaterials and methods: In terms of the principle of clinical design,every component of RPD such as clasp , rest , palate bar ,and mesh construction were built using engineering software.Results:he computer-aided 3-D upper casting framework were completed,and can be rotated, enlarged and shrunk in any direction.Conclusion: It is a new method to computer aid the RPD framework for clinical cases. It made a foundation of the CAM for RPD framework. PartⅢ3-D computer-aided manufacture of removable partial denture casting framework for clinical patientsMaterials and methods: The data of framework was converted to STL file format and transferred to rapid prototyping equipment for manufacture. The resin framework was cast in chromium–cobalt alloy without using a refractory cast.Results:Preliminarily, a clinical chromium–cobalt alloy framework was manufactured using CAD/CAM.Conclusion: It is suggested that this method based on engineering software and rapid prototyping techniques in CAD/CAM of RPD framework be feasible.