Research On Slurry Micro-extrusion Of Rapid Prototyping For Preparation Of 3Y-ZrO₂ All-Ceramic Crowns

With the progress of oral medicine development and denture processing technology, the use of the all-ceramic crowns to repair dentition is more and more popular with patients. Advantages of 3Y-ZrO2 ceramic for its excellent physical and chemical properties, good biological compatibility, natural color stability etc. have become the current application of the most extensive all-ceramic crowns preparation materials. Traditional all-ceramic crowns are prepared by the use of dental CAD/CAM engraving machine, but the characteristics of 3Y-ZrO2 ceramic material with high strength and high hardness, resulting in machining difficulty, resulted in the high cost of all-ceramic crown, and in a certain extent limits the all-ceramic crowns restoration technology development. With the rapid development of the rapid prototyping technology which in many fields obtained widely used, slurry micro extrusion rapid prototyping technology as a slurry form of the preparation of new technology of ceramic parts can be unrestricted forming complex ceramic structure of the entities, this paper is base on micro extrusion mechanism of rapid prototyping, building a micro extrusion rapid prototyping experiment platform for SME slurry,3Y-ZrO2 ceramic slurry for molding material, the technology will be used in prosthodontics all-ceramic crowns of preparation, on the process were exploratory research, designed for all-ceramic crowns by seeking a new path.First design and machining of micro can meet the slurry micro extrusion forming process of slurry extrusion mechanism, and makes optimization, designs selection of key parts of them to do a detailed description, then combined with X,Y,Z transmission parts, forming platform and a control box, on the experimental platform is built.Using ammonium polymethacrylate as dispersant and study of 3Y-ZrO2 ceramic slurry dispersion at different pH values and dispersion agent viscosity and sedimentation height change. When pH=9, dispersion agent addition 3Y-ZrO2 ceramic powder particles 1.5wt% for obtaining the best dispersion effect is obtained. According to the characteristics of SME molding process, the content of other components and the solid content of ceramic powder will be determined, and the formula of 3Y-ZrO2 ceramic slurry with the best forming solid content was obtained.Through theoretical calculation and practical experiment for seeking 3Y-ZrO2 ceramic slurry molding, the optimum process parameters are obtained with all-ceramic crowns generation mode three-dimensional molding, it carries on the analysis and solution are described in detail the main factors of affecting the quality of molding and molding biscuit were preliminary sintering test. Determination of the samples volume shrinkage after sintering, and to compressive strength and natural teeth experiments were compared to obtain test samples are exposed to the maximum resistance to pressure were significantly higher than the natural teeth and the test samples can meet all-ceramic crowns mechanics performance requirements.