Calberson F L G, Deroose C A J G, Hommez G M G, De Moor R J G
Department of Operative Dentistry and Endodontology, Dental School, Ghent University, Ghent University Hospital, Gent, Belgium.
Int Endod J. 2004 Sep;37(9):613-23. doi: 10.1111/j.1365-2591.2004.00860.x.
To determine the shaping ability of ProTaper instruments in simulated root canals.
Forty canals with four different shapes in terms of angle (20 degrees and 40 degrees) and position of curvature (straight section before curve: 8 and 12 mm) were enlarged according to the recommendations of the manufacturer with the finishing files F1, F2 and F3 to full working length. Preoperative and postoperative pictures, recorded using a digital camera, were superimposed and aberrations recorded. Measurements were carried out at five different points: at the canal orifice (O); half-way to the orifice in the straight section (HO); beginning of the curve (BC); apex of the curve (AC); end-point (EP).
Ten instruments deformed (nine F3 and one S1, all in canals with straight section of 8 mm), one instrument fractured. There were significant differences between the various canal shapes for the amount of resin removed from the inner curve at all points (O: P < 0.05; HO: P = 0.001; BC, AC and EP: P < 0.001); and for the resin removed on the outer curve at points HO, AC and EP (P < 0.001). Mean transportation was towards the inner aspect of the curve in all canal types at points BC, towards the outer aspect at the end-point of preparation (EP) in all canals with 12 mm straight section. In 8 mm straight section canals, four danger zones were found; in 12 mm straight section canals three zips were present. The canal aberrations were produced following the use of the F2 and F3 instruments. There were no aberrations following the use of the F1 instrument.
Under the conditions of this study, ProTaper instruments performed acceptable tapered preparations in all canal types. When using F2 and F3 in curved canals, care should be taken to avoid excessive removal at the inner curve, leading to danger zones. In addition, care should also be taken to avoid deformation of the F3 instrument.
确定ProTaper器械在模拟根管中的塑形能力。
根据制造商的建议，使用F1、F2和F3号完成锉将40个具有四种不同角度（20度和40度）和弯曲位置（弯曲前直段长度：8和12毫米）的根管扩大至工作长度。术前和术后使用数码相机拍摄的照片进行叠加，并记录偏差。在五个不同点进行测量：根管口（O）；直段距根管口一半处（HO）；弯曲起始点（BC）；弯曲顶点（AC）；终点（EP）。
10根器械发生变形（9根F3号和1根S1号，均在直段长度为8毫米的根管中），1根器械折断。在所有测量点，不同根管形态从内弯曲处去除的树脂量存在显著差异（O点：P < 0.05；HO点：P = 0.001；BC、AC和EP点：P < 0.001）；在HO、AC和EP点从外弯曲处去除的树脂量也存在显著差异（P < 0.001）。在所有根管类型的BC点，平均移位方向均朝向弯曲内侧；在直段长度为12毫米的所有根管的预备终点（EP），移位方向朝向外侧。在直段长度为8毫米的根管中发现了四个危险区；在直段长度为12毫米的根管中有三个拉链状区域。使用F2和F3号器械后出现根管偏差，使用F1号器械后未出现偏差。
在本研究条件下，ProTaper器械在所有根管类型中均能进行可接受的锥形预备。在弯曲根管中使用F2和F3号器械时，应注意避免在内弯曲处过度去除，导致危险区。此外，还应注意避免F3号器械变形。
