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。

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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。

youdao