Whitbeck Evan R, Quinn George D, Quinn Janet B
Comprehensive Dentistry Department, Naval Postgraduate Dental School, Bethesda, MD 20889.
American Dental Assocoation Foundation, Paffenbarger Research Center, National Institute of Standards and Technology, Gaithersburg, MD 20899.
J Res Natl Inst Stand Technol. 2011 Aug 1;116(4):743-9. doi: 10.6028/jres.116.017. Print 2011 Jul-Aug.
An increased incidence of fracture has been reported in teeth where root canals were treated with calcium hydroxide. Edge chipping is one test used to measure the resistance of brittle materials to fracture. Presently, no studies have reported on edge chipping in teeth. This study evaluated the fracture resistance of human dentin exposed to calcium hydroxide for up to 60 days using the edge chipping method. Twelve recently extracted teeth were divided into a control group and three experimental groups with varying calcium hydroxide exposures. All teeth underwent pulpectomy via standard protocol. It was expected that the edge chip resistance would decrease as a function of exposure, but the results showed the converse. Chip resistance may reflect both the fracture resistance and the hardness of dentin, a quasi brittle material.
据报道，用氢氧化钙进行根管治疗的牙齿骨折发生率增加。边缘崩裂是一种用于测量脆性材料抗断裂性的测试。目前，尚无关于牙齿边缘崩裂的研究报道。本研究采用边缘崩裂法评估了暴露于氢氧化钙长达60天的人牙本质的抗断裂性。将12颗近期拔除的牙齿分为一个对照组和三个氢氧化钙暴露时间不同的实验组。所有牙齿均通过标准方案进行牙髓摘除术。预期边缘崩裂抗力会随暴露时间而降低，但结果却相反。崩裂抗力可能反映了牙本质（一种准脆性材料）的抗断裂性和硬度。
