Preparation Of ZrO₂All-ceramic Crown Based On MAM Freeform Fabracation

All-ceramic crowns have been widely used in the field of prosthodontics with theimprovement of people’s living standard, and zirconia（ZrO₂） is the best material forpreparation of all-ceramic crowns because of its excellent mechanical properties andbiocompatibility. The traditional method of preparing ZrO₂all-ceramic crown is CAD/CAM technology, the ceramic block need to be pre-sinteringed firstly and then machineddue to its high hardness and strength. The progress is complex and inefficient, so itsapplication is limited. Freeform fabrication with micro-droplet jetting is a typicalfreeform fabrication based on the principle of addition manufacturing, and a very widerange of materials can be used in this method, so it is very suitable for rapid prototypinga variety of three-dimensional solid. In this paper,“MAM （motor assistedmicrosyringe） freeform fabrication system” is used to fabrication the ZrO₂all-ceramiccrown. Meanwhile, we explore and research the entire process.The stability and dispersion of ZrO₂ceramic slurry is researched. We explore theinfluence law of the slurry PH and the amount of dispersan,t and get the optimal contentby experiment. Then get the content of other additives and the optimal solid fractionaccording to the technological characteristics of MAM.To research the characteristics of MAM freeform fabrication process, theoreticalcalculation and experimental are combined and injection process parameters of ZrO₂ceramic slurry are explored. The parameters are applied to the MAM freeformfabrication of ZrO₂all-ceramic crowns, and then get the comprehensive analysis andsummary of the major process problem.The ZrO₂ceramic is pressureless sintered and sintering properties are tested. Wefound that the ZrO₂ceramic with stable phase and dense microstructure is obtained at1400℃, and the flexural strength is607.2MPa. Then we found that liquid-phase sintering process can significantly enhance the sintering properties of the ZrO₂ceramicprepared by MAM, and the flexural strength is increased to723.8MPa at1400℃,thereby obtain a reasonable sintering process.