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本研究调查了各种铸道的设计,铸造机及热源(五种常用铸道方法,四种常用铸造机和热源)对铸件多孔性的影响。材料和方法:制作60件颊(牙合)面用烤瓷覆盖的铸件,分为三类:前磨牙全冠、磨牙全冠、前磨牙桥体。制作上颌第一前磨牙和第一磨牙金属烤瓷修复体的帽状冠蜡型,并各复制20个,分为四组,按照设计的五种铸道方式安插铸道。用磷酸镁包埋材料包埋,放置一小时后,置于炉内预热到600℉,持续30分钟,再转入烤炉预热到1200℉,持续一小时。用新的烤
This study investigated the effects of various runner designs, casting machines and heat sources (five common casting methods, four commonly used casting machines and heat sources) on the porosity of the castings. MATERIALS AND METHODS: 60 pieces of castings covered with porcelain on the buccal surface were prepared and divided into three categories: full molars, full molars and premolar bridges. Making the crown-like crown wax of the maxillary first premolar and the first molar metal-porcelain restoration, each of them was duplicated into 20 groups and divided into 4 groups. Embedded with magnesium phosphate-embedded material, placed for one hour, placed in a furnace preheated to 600 ° F for 30 minutes and then transferred to the oven preheated to 1200 ° F for an hour. With new grilled