J Korean Acad Conserv Dent.  2006 May;31(3):179-185. 10.5395/JKACD.2006.31.3.179.

Effect of rotational speed of Protaper(TM) rotary file on the change of root canal configuration

• Seo MC
• Jeon YJ
• Kang IC
• Kim DJ
• Hwang YC
• Hwang IN
• Oh WM

• KMID: 2175817
• DOI: http://doi.org/10.5395/JKACD.2006.31.3.179

Abstract

This study was conducted to evaluate canal configuration after shaping by ProTaper(TM) with various rotational speed in J-shaped simulated resin canals. Forty simulated root canals were divided into 4 groups, and instrumented using by ProTaper(TM) at the rotational speed of 250, 300, 350 and 400 rpm. Pre-instrumented and post-instrumented images were taken by a scanner and those were superimposed. Outer canal width, inner canal width, total canal width, and amount of transportation from original axis were measured at 1, 2, 3, 4, 5, 6, 7 and 8 mm from apex. Instrumentation time, instrument deformation and fracture were recorded. Data were analyzed by means of one-way ANOVA followed by Scheffe's test. The results were as follows 1. Regardless of rotational speed, at the 1~2 mm from the apex, axis of canal was transported to outer side of a curvature, and at 3~6 mm from the apex, to inner side of a curvature. Amounts of transportation from original axis were not significantly different among experimental groups except at 5 and 6 mm from the apex. 2. Instrumentation time of 350 and 400 rpm was significantly less than that of 250 and 300 rpm (p < 0.01). In conclusion, the rotational speed of ProTaper(TM) files in the range of 250~400 rpm does not affect the change of canal configuration, and high rotational speed reduces the instrumentation time. However, appearance of separation and distortion of Ni-Ti rotary files can occur in high rotational speed.

Keyword

Rotational speed; Canal configuration; Image analysis

MeSH Terms

Axis, Cervical Vertebra
Dental Pulp Cavity*
Transportation

Figure

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  Figure 1 Pre-instrumentation image. Working length was 16 mm, the round circles were the landmark for getting the superimposed image.

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  Figure 2 The diagram indicates the points at which the canal width was measured after superimposition of pre-instrumentation and post-instrumentation image.

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