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医学免费论文:不同离子交换时间和温度对白榴石增强陶瓷弯曲强度的影响
【摘要】目的: 研究不同离子交换时间和温度对白榴石增强陶瓷双轴弯曲强度的影响，为临床应用提供参考. 方法: 试件的蜡型制作采用将融化的铸造蜡灌注于机械加工模具内，制成厚度和直径一致的蜡型. 厚度为2.0 mm，直径为18 mm圆片，共90个. 实验分组首先按照同一时间下不同温度即离子交换温度为400℃，450℃，500℃，离子交换时间为3 h，每组试件10个. 然后在确定最佳离子交换温度的基础上以不同时间分组即交换时间为3，5，7，9，11 h，每组试件10个. 以不做打磨、上釉和离子交换的为对照组，试件为10个. 根据ASTM标准 F39478.1991（美国材料实验协会)测试试件的双轴弯曲强度. 经oneway ANOVA及KruskalWallis秩和检验统计分析各实验组. 结果: 同一处理时间不同处理温度下的双轴弯曲强度经统计分析可知有统计学差异(P<0.01). 同一处理温度不同处理时间下的双轴弯曲强度经统计分析可知有统计学差异(P<0.01). 与对照组比较均存在统计学差异(P<0.01). 结论: cerinate热压铸陶瓷的离子交换处理较佳的温度为450℃，时间为11 h.
【关键词】 牙瓷料；陶瓷；离子交换；双轴弯曲强度
Effect of different time/temperature of ion exchange on the biaxial flexural strength of heat pressed ceramic
WANG Hui, CHEN JiHua, SHI ChangXi, SHEN LiJuan
Department of Prosthodontics, College of Stomatology, Fourth Military Medical University, Xian 710033, China
【Abstract】 AIM: To study the effect of different time/temperature of ion exchange on the biaxial flexural strength of heat pressed ceramic. METHODS: Eighty disks of Cerinate ceramic specimens (shade 2), 18 mm in diameter and 2.0 mm thick, were prepared. The specimens were manufactured according to the companys recommendations. Ten disks were used as controls. The remaining disks were divided into 7 groups of 10 disks each and ionexchanged specimens were made by the treatment of potassium salt at 400℃, 450℃, 500℃ for 3 h and at the optimal temperature for 5, 7, 9, 11 h. The biaxial flexural strength was evaluated by a threepoint bending in a universal machine according to ASTM Standard (F39478.1991). RESULTS: The biaxial flexural strength had significant difference among different treatment temperature and time groups (P<0.01). Compared with control group, the biaxial flexural strength of each experimental group was also statistically significantly different (P<0.01). CONCLUSION: The ionexchange process of the Cerinate hot pressed ceramic should be performed at 450℃ for 11 h.
【Keywords】 dental porcelain; porcelain; ionexchange; biaxial flexural strength医.学.全.在.线www.med126.com
0引言
随着人们对牙科修复体的美观要求的增加,越来越多的临床医生关注于陶瓷材料的美观性和生物相容性，但由于陶瓷材料自身的缺点如脆性大、强度差. 作为牙科修复材料在烧结过程中在瓷表面形成张应力和微裂纹，从而降低了陶瓷的强度，影响其在口腔复杂的化学环境下的使用寿命. 因此应运而生了陶瓷表面增强技术，以减少和防止陶瓷表面微裂纹的产生和扩散. 陶瓷表面增强技术的离子在陶瓷表面的扩散率受交换的温度和交换时间的影响，因此需要确定最佳的交换时间和温度，使热压铸陶瓷表面强度获得最佳, 为临床应用提供依据和参考.
