Published online Jul 30, 2005.
https://doi.org/10.5395/JKACD.2005.30.4.303
The change of canal configuration after instrumentation by several nickel-titanium files in the simulated canal with abrupt curvature
Abstract
The purpose of this study was to evaluate which type of Ni-Ti files are able to maintain canal configuration better in the simulated canal with abrupt curvature near it's apex.
Ninety six simulated root canals were made in epoxy resin and #15 finger spreader was used as root canal templates. The simulated root canals were made with radius of curvature of 1.5 mm, 3.0 mm, 4.0 mm, 6.0 mm respectively and the angle of curvature of all simulated canals were adjusted to 90 degree. The simulated canals were instrumented by ProFile, ProTaper, Hero 642, and K3 at a 300 rpm using crown-down pressureless technique. Pre-instrumented and post-instrumented images were taken by digital camera and were superimposed with Adobe Photoshop 6.0 program. Images were compared by image analysis program.
The changes of canal width at the inner and outer side of the canal curvature, canal transportation were measured at 9 measuring point with 1 mm interval. Statistical analysis among the types of Ni-Ti files was performed using Kruskal-Wallis test and Mann-Whitney U-test.
The result was that ProFile maintain original canal configuration better than other engine driven Ni-Ti files in the canals above 3.0 mm radius of curvature, and in the 1.5 mm radius of curvature, most of Ni-Ti flies were deformed or separated during instrumentation.
Figure 1
4.0 mm radius of curvature of finger spreader
Figure 2
Pre- and Post-image of root canal and Measuring points were measured with 1 mm interval from 1 mm to 9 mm.
Figure 3
*significant difference among Ni-Ti files at each measuring point (p < 0.05).
Change of total canal width of the curvature in 3.0 mm radius group (Unit: mm).
Figure 4
*significant difference among Ni-Ti files at each measuring point (p < 0.05). **significant difference among Ni-Ti files at each measuring point (p < 0.01).
Change of total canal width of the curvature in 4.0 mm radius group (Unit: mm).
Figure 5
*significant difference among Ni-Ti files at each measuring point (p < 0.05). **significant difference among Ni-Ti files at each measuring point (p < 0.01).
Change of total canal width of the curvature in 6.0 mm radius group (Unit: mm).
Figure 6
*significant difference among Ni-Ti files at each measuring point (p < 0.05). **significant difference among Ni-Ti files at each measuring point (p < 0.01). Negative value means inside transportation from
central axis of original root canal.
Canal transportation of 3.0 mm radius group (Unit: mm).
Figure 7
*significant difference among Ni-Ti files at each measuring point (p < 0.05). **significant difference among Ni-Ti files at each measuring point (p < 0.01). Negative value means inside transportation from central axis of original root canal.
Canal transportation of 4.0 mm radius group (Unit : mm).
Figure 8
*significant difference among Ni-Ti files at each measuring point (p < 0.05). **significant difference among Ni-Ti files at each measuring point (p < 0.01). Negative value means inside transportation from central axis of original root canal.
Canal transportation of 6.0 mm radius group (Unit : mm).
Table 1
The number of ledge formation and File fracture
Table 2
Deformation and separation of Ni-Ti files
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