Long-term calcium hydroxide as a root canal dressing may increase risk of root fracture
Long-term calcium hydroxide as a root canal dressing may increase risk of root fracture
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DOI：
10.1034/j.1600-9657.2002.00097.x
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发表时间：
2002-06-01
影响因子：
2.5
通讯作者：
Munksgaard, C
中科院分区：
文献类型：
--
作者：
Andreasen, JO;Farik, B;Munksgaard, C
有人提出（Cvek 1992），通过用氢氧化钙敷料和古塔胶填充根管来削弱未成熟的牙齿。本研究的目的是检验牙本质与氢氧化钙接触一段时间后断裂强度会降低的假设。拔出绵羊未成熟的下颌切牙并分为两个实验组。第1组：通过根尖孔摘除牙髓。然后用氢氧化钙 (Calasept(R)) 填充根管并用 IRM(R) 水泥进行刮治，然后将牙齿在室温下保存在盐水中 0.5、1、2、3、6、9 或 12 个月。第2组：拔除牙髓，用盐水填充根管并用IRM(R)水泥密封。然后将牙齿在盐水中保存两个月。完整的牙齿作为对照，并在拔牙后立即进行测试。在指定的观察周期内，所有牙齿均在英斯特朗试验机中进行了断裂强度测试。结果显示，第一组（氢氧化钙敷料）的断裂强度随着储存时间的增加而显着下降。结果表明，氢氧化钙填充的未成熟牙齿的断裂强度会因牙根填充而在大约一年内减半。这一发现或许可以解释为什么经常报道的长期填充氢氧化钙的未成熟牙齿会发生骨折。
It has been proposed (Cvek 1992) that immature teeth are weakened by filling of the root canals with calcium hydroxide dressing and gutta-percha. The aim of the present study was to test the hypothesis that dentin in contact with calcium hydroxide would show a reduction in fracture strength after a certain period of time. Immature mandibular incisors from sheep were extracted and divided into two experimental groups. Group 1: the pulps were extirpated via the apical foramen. The root canals were then filled with calcium hydroxide (Calasept((R))) and scaled with IRM(R) cement, and the teeth were then stored in saline at room temperature for 0.5,1, 2, 3, 6, 9, or 12 months. Group 2: the pulps were extirpated and the root canals were filled with saline and sealed with IRM(R) cement. The teeth were then stored in saline for 2 months. Intact teeth served as controls and were tested immediately after extraction. All teeth were tested for fracture strength in an Instron testing machine at the indicated observation periods. The results showed a markedly decrease in fracture strength with increasing storage time for group I (calcium hydroxide dressing). The results indicate that the fracture strength of calcium hydroxide-filled immature teeth will be halved in about a year due to the root filling. The finding may explain the frequent reported fractures of immature teeth filled with calcium hydroxide for extended periods.