目的:评价次氯酸钠(NaOCl)与羟基亚乙基二膦酸(HEDP)或乙二胺四乙酸(EDTA)联合治疗根管牙本质的力学性能。
方法:为了测试抗断裂性,用NaOCl/HEDP对45颗单根牙齿进行了仪器和灌溉,NaOCl/EDTA,或蒸馏水。15颗未经处理的牙齿作为对照。闭塞后,对实验组的标本进行了热循环,动态加载,然后在万能试验机中静态加载直到失效。对于弯曲强度分析,用NaOCl/HEDP或NaOCl/EDTA对15颗牙齿进行仪器和冲洗。将根段切成牙本质棒,并使用通用试验机测试弯曲强度。对于显微硬度评估,用NaOCl/HEDP或NaOCl/EDTA对20颗牙齿进行仪器和冲洗。准备了每个根段冠状三分之一的牙本质盘,一个在灌溉之前,一个在灌溉之后,用努普硬度测试仪进行显微硬度测试。
结果:未治疗组的抗骨折能力最高,在EDTA组中最低。虽然HEDP组比EDTA组有更高的抗骨折能力,蒸馏水组比HEDP组表现出更高的抗断裂性。与用EDTA处理的样品相比,用HEDP处理的样品具有明显更高的弯曲强度和显微硬度值。
结论:抗骨折,抗弯强度,用NaOCl/HEDP冲洗根管时,根管牙本质的显微硬度更高,与NaOCl/EDTA相比。
结论:与使用NaOCl和EDTA相比,用NaOCl和HEDP联合灌注根管显著改善了根管牙本质的机械完整性。
OBJECTIVE: To evaluate the mechanical properties of root canal dentin treated with sodium hypochlorite (NaOCl) in combination with hydroxyethylidene diphosphonic acid (HEDP) or ethylenediaminetetraacetic acid (EDTA).
METHODS: For testing fracture resistance, 45 single-rooted teeth were instrumented and irrigated with NaOCl/HEDP, NaOCl/EDTA, or distilled water. Fifteen untreated teeth served as control. After obturation, specimens from the experimental groups were thermocycled, dynamically-loaded, and then statically-loaded in a universal testing machine until failure. For flexural strength analysis, 15 teeth were instrumented and irrigated with NaOCl/HEDP or NaOCl/EDTA. Root segments were sectioned into dentin bars and tested for flexural strength using a universal testing machine. For microhardness evaluation, 20 teeth were instrumented and irrigated with NaOCl/HEDP or NaOCl/EDTA. Dentin disks from the coronal-third of each root segment were prepared, one before and one after irrigation, for microhardness testing with a Knoop hardness tester.
RESULTS: The highest fracture resistance was recorded in the untreated group, and the lowest in the EDTA group. Although the HEDP group had higher fracture resistance than the EDTA group, the distilled water group demonstrated even greater fracture resistance than the HEDP group. Specimens treated with HEDP had significantly higher flexural strength and microhardness values when compared with those treated with EDTA.
CONCLUSIONS: The fracture resistance, flexural strength, and microhardness of root canal dentin were higher when root canals were irrigated with NaOCl/HEDP, when compared with NaOCl/EDTA.
CONCLUSIONS: Irrigating root canals with NaOCl combined with HEDP significantly improves the mechanical integrity of root canal dentin compared to the use of NaOCl with EDTA.