The third group were prepared using the stainless steel hand K-files with the step-down technique(SS group).
不锈钢K锉组（SS）采用常规手用不锈钢K锉、逐步后退法预备根管。
METHODS: 25 extracted human maxillary anterior teeth, with a single straight root were randomly divided into 5 groups. They were instrumented with K-files and conventional preparation technique.
方法：25颗离体直根管前牙，随机分为5组，不锈钢K锉常规法预备根管，应用5种冲洗剂组合进行冲洗。
The /etc/rc.d directory structure can be used to put in S and K files at the various run levels listed to bring up or down processes.
可以使用 /etc/rc.d 目录结构在列出的各个运行级别上放入 S 和 K 文件，以启用或停止进程。
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