Lottanti S, Gautschi H, Sener B, Zehnder M
Department of Preventive Dentistry, Periodontology and Cariology, University of Zürich, Zürich, Switzerland.
Int Endod J. 2009 Apr;42(4):335-43. doi: 10.1111/j.1365-2591.2008.01514.x. Epub 2009 Feb 7.
To evaluate the effects of ethylenediaminetetraacetic (EDTA), etidronic (EA) and peracetic acid (PA) when used in conjunction with sodium hypochlorite (NaOCl) as root canal irrigants on calcium eluted from canals, smear layer, and root dentine demineralization after instrumentation/irrigation.
Single-rooted human premolars were irrigated as follows (n = 12 per group): (1) 1% NaOCl during instrumentation, deionized water after instrumentation, (2) 1% NaOCl during, 17% EDTA after instrumentation, (3) a 1 : 1-mixture of 2% NaOCl and 18% EA during and after instrumentation, and (4) 1% NaOCl during, 2.25% PA after instrumentation. Irrigant volumes and contact times were 10 mL/15 min during and 5 mL/3 min after instrumentation. The evaluated outcomes were eluted calcium by atomic absorption spectroscopy, smear-covered areas by scanning electron microscopy in secondary electron mode and apparent canal wall decalcifications on root transsections in backscatter mode. For the smear layer analysis, sclerotic dentine was taken into consideration. Results were compared using appropriate parametric and nonparametric tests, alpha = 0.05.
The statistical comparison of the protocols regarding calcium elution revealed that protocol (1) yielded less calcium than (3), which yielded less than protocols (2) and (4). Most of the instrumented canal walls treated with one of the decalcifying agents were free of smear layer. Protocols (1) and (3) caused no decalcification of root dentine, whilst (2) and (4) showed substance typical demineralization patterns.
The decalcifying agents under investigation were all able to remove or prevent a smear layer. However, they eroded the dentine wall differently.
评估乙二胺四乙酸（EDTA）、依替膦酸（EA）和过氧乙酸（PA）与次氯酸钠（NaOCl）联合用作根管冲洗剂时，对根管内洗脱钙、玷污层以及预备/冲洗后牙根牙本质脱矿的影响。
对单根人前磨牙进行如下冲洗（每组n = 12）：（1）预备期间用1% NaOCl，预备后用去离子水；（2）预备期间用1% NaOCl，预备后用17% EDTA；（3）预备期间及预备后用2% NaOCl和18% EA的1:1混合液；（4）预备期间用1% NaOCl，预备后用2.25% PA。预备期间冲洗液体积和接触时间为10 mL/15分钟，预备后为5 mL/3分钟。评估指标包括通过原子吸收光谱法测定洗脱钙、在二次电子模式下用扫描电子显微镜观察玷污覆盖面积以及在背散射模式下观察牙根横断面的明显根管壁脱钙情况。对于玷污层分析，考虑了硬化牙本质。使用适当的参数和非参数检验比较结果，α = 0.05。
关于钙洗脱的方案的统计比较显示，方案（1）洗脱的钙比方案（3）少，方案（3）又比方案（2）和（4）少。用一种脱钙剂处理的大多数预备根管壁没有玷污层。方案（1）和（3）未导致牙根牙本质脱钙，而方案（2）和（4）显示出典型的物质脱矿模式。
所研究的脱钙剂均能够去除或防止玷污层形成。然而，它们对牙本质壁的侵蚀方式不同。
