Ayar L R, Love R M
Department of Oral Diagnostic and Surgical Sciences, University of Otago School of Dentistry, Dunedin, New Zealand.
Int Endod J. 2004 Sep;37(9):593-601. doi: 10.1111/j.1365-2591.2004.00851.x.
To compare the shaping ability of ProFile and K3 rotary Ni-Ti instruments when used in a variable tip sequence in simulated curved root canals with different curvature and radius.
ProFile or K3.06 taper instruments were used to prepare simulated canals of 20 degrees curvature and 5 mm radius (n = 10) and 30 degrees curvature and 3 mm radius canals (n = 10) in resin blocks. All canals were prepared to an apical size 40 at 0.5 mm from the canal terminus using a variable tip crown-down sequence. Pre- and postinstrumentation digital images were recorded, and an assessment of the canal shape was determined using a computer image analysis program. The material removal from the inner and outer wall of the canal was measured at 28 measuring points, beginning 0.5 mm from the end-point of the canal and the data compared using the Mann-Whitney U-test.
In 20 degrees and 30 degrees canals both instruments significantly removed more (P < 0.05) material on the outer wall than the inner wall in the apical half of the canal. For ProFile files there was no significant difference in the amount of material removed on the outer canal wall between the 20 degrees and 30 degrees canals. However, in the K3 groups significantly more (P < 0.05) outer canal wall was removed in the apical area in 20 degrees canals. When comparing both instruments the results showed that in 20 degrees canals K3 instruments removed more outer and inner canal wall than ProFile instruments (P < 0.05) but that there was no significant difference (P > 0.05) between the instruments in 30 degrees canals.
Within the limitation of this study, both rotary nickel-titanium instruments prepared a well-shaped root canal with minimal canal transportation.
比较ProFile和K3旋转镍钛器械在模拟不同曲率和半径的弯曲根管中采用可变尖端顺序使用时的根管预备能力。
使用ProFile或K3.06锥度器械在树脂块中预备曲率为20度、半径为5mm的模拟根管（n = 10）以及曲率为30度、半径为3mm的根管（n = 10）。所有根管均采用可变尖端冠向下顺序预备至距根管末端0.5mm处的根尖尺寸40。记录器械使用前后的数字图像，并使用计算机图像分析程序确定根管形态评估。从根管内壁和外壁去除的材料在距根管终点0.5mm处开始的28个测量点进行测量，并使用Mann-Whitney U检验比较数据。
在20度和30度根管中，两种器械在根管根尖半部的外壁去除的材料均明显多于内壁（P < 0.05）。对于ProFile锉，20度和30度根管在外壁去除的材料量上没有显著差异。然而，在K3组中，20度根管根尖区域的外壁去除量明显更多（P < 0.05）。比较两种器械时，结果显示在20度根管中，K3器械比ProFile器械去除的外壁和内壁更多（P < 0.05），但在30度根管中两种器械之间没有显著差异（P > 0.05）。
在本研究的局限性内，两种旋转镍钛器械均能预备出形态良好且根管偏移最小的根管。
