METHODS: A total of 40 single bend resin simulated root canals were randomly divided into 4 groups with 10 in each group. Four kinds of nickel-titanium instruments (ProTaper, HyFlex EDM, WaveOne Gold and Reciproc Blue) were used for root canal preparation, and divided into group A, group B, group C and group D. The preparation time of the four groups was compared, the root canal images before and after preparation were analyzed by computer image analysis software, and the changes of the preparation time, curvature and curvature radius of the four groups were recorded. With the root tip as the center of the circle, the radius of 1-10 mm was selected as concentric circle arcs. The detection points were overlapping root canal intersection points. The resin removal amount and center positioning force of the inner and outer walls of the root canal at different detection points were recorded. Statistical analysis was performed with SPSS 20.0 software package.
RESULTS: The root canal preparation time in group A was significant longer than that in group B, C and D(P<0.05), but there was no significant difference in the curvature and curvature radius of the root canal among the four groups (P>0.05). The removal amount of resin from the root canal wall in group C was significant lower than that in group A, B and D (P<0.05) when the distance from the detection point to the apical foramina was 5, 6, 8, 9 and 10 mm, respectively. The removal amount of resin from the outer wall of the root canal in group C was significant lower than that in group A, B and D (P<0.05) when the distance from the detection point to the apical foramina was 5, 6, 7, 9 and 10 mm, respectively. The root tip offset of group A from the detection point to the apical hole of 1, 2, 3, 4, 6, 7, 8, 9 and 10 mm was significant greater than that of group B, C and D(P<0.05).
CONCLUSIONS: Among the four instruments, ProTaper has the largest apical deviation, HyFlex EDM, WaveOne Gold and Reciproc Blue have better ability of root canal forming.
方法:将40个单弯树脂模拟根管随机分为4组,每组10个。四种镍钛仪器(ProTaper,HyFlex电火花,WaveOneGold和ReciprocBlue)用于根管准备,分成A组,B组,比较四组的准备时间,通过计算机图像分析软件对制备前后的根管图像进行分析,以及准备时间的变化,记录四组的曲率和曲率半径。以根尖为圆心,选择1-10mm的半径作为同心圆弧。检测点是重叠的根管交叉点。记录不同检测点根管内外壁的树脂去除量和中心定位力。采用SPSS20.0软件包进行统计学分析。
结果:A组根管预备时间明显长于B组,C和D(P<0.05),但四组根管的曲率和曲率半径差异无统计学意义(P>0.05)。C组根管壁树脂去除量显著低于A组,当检测点到根尖孔的距离为5、6、8、9和10mm时,B和D(P<0.05),分别。C组根管外壁树脂的清除量明显低于A组,当检测点到根尖孔的距离为5、6、7、9和10mm时,B和D(P<0.05),分别。A组从检测点到根尖孔1、2、3、4、6、7、8、9和10mm的根尖偏移明显大于B组,C和D(P<0.05)。
结论:在四种仪器中,ProTaper具有最大的根尖偏差,HyFlex电火花,WaveOne金和Reciproc蓝具有更好的根管形成能力。