Liu Dan, Yu Jing-Tao, Qiu Li-Hong
Department of Stomatology, The Second Hospital of Tianjin Medical University. Tianjin 300211, China. E-mail:
Shanghai Kou Qiang Yi Xue. 2022 Feb;31(1):58-61.
To investigate the effect of titanium nitride (TiN) coatings with different thicknesses on microhardness and cutting efficiency of nickel-titanium (NiTi) instruments, and to provide a basis for improving the efficiency of clinical root canal preparation.
Fifteen KV4 NiTi alloy sheets and sixty KV4 rotary NiTi files were selected and randomly divided into 5 groups: uncoated group, coating 1 h group, coating 2 h group, coating 3 h group and coating 4 h group. A layer of TiN coatings of different thicknesses was prepared on the surface of the coated groups by controlling the deposition time. The film thickness of each group was measured by scanning electron microscopy (SEM). The microhardness of each group of NiTi alloy sheets was measured by a Vickers hardness tester. Sixty transparent resin modules were selected and each resin module was prepared with one NiTi file. The cutting efficiency of each group was measured by the weight loss method. SEM was used to examine the surface of NiTi instruments in 5 groups before and after preparation. One-way variance analysis was used to determine the statistical differences with SPSS 22.0 software package.
With the increase of the thickness of titanium nitride coating, the microhardness of NiTi alloy gradually increased(P＜0.05). With the increase of the thickness of titanium nitride coating, the cutting efficiency of NiTi instrument was improved, and the cutting efficiency was the largest when the coating thickness was 860 nm(P＜0.05). The surface morphology of the coated group was better than that of the uncoated group.
The thickness of TiN coating affects microhardness and cutting efficiency of the nickel-titanium instruments, the microhardness and cutting ability enhanced as the thickness increased. If the thickness is too large, the cutting efficiency will be reduced.
探讨不同厚度的氮化钛（TiN）涂层对镍钛（NiTi）器械显微硬度和切削效率的影响，为提高临床根管预备效率提供依据。
选取15片KV4 NiTi合金片和60支KV4旋转NiTi锉，随机分为5组：未涂层组、涂层1小时组、涂层2小时组、涂层3小时组和涂层4小时组。通过控制沉积时间在涂层组表面制备一层不同厚度的TiN涂层。每组的膜厚通过扫描电子显微镜（SEM）测量。每组NiTi合金片的显微硬度用维氏硬度计测量。选取60个透明树脂模块，每个树脂模块用一支NiTi锉进行预备。每组的切削效率用失重法测量。用SEM观察5组NiTi器械预备前后的表面情况。采用单因素方差分析，使用SPSS 22.0软件包确定统计学差异。
随着氮化钛涂层厚度的增加，NiTi合金的显微硬度逐渐增加（P＜0.05）。随着氮化钛涂层厚度的增加，NiTi器械的切削效率提高，涂层厚度为860 nm时切削效率最大（P＜0.05）。涂层组的表面形态优于未涂层组。
TiN涂层厚度影响镍钛器械的显微硬度和切削效率，随着厚度增加，显微硬度和切削能力增强。若厚度过大，切削效率会降低。
