J Korean Acad Conserv Dent.  2011 Jul;36(4):300-305. 10.5395/JKACD.2011.36.4.300.

Evaluation of canal preparation for apical sealing with various Ni-Ti rotary instruments

• Shin Y
• Shin SJ
• Song M
• Kim E

• KMID: 1986692
• DOI: http://doi.org/10.5395/JKACD.2011.36.4.300

Abstract

OBJECTIVES
The aim of this study was to evaluate the various NiTi rotary instruments regarding their ability to provide a circular apical preparation.
MATERIALS AND METHODS
50 single canal roots were selected, cut at the cementodentinal junction and the coronal 1/3 of the canals was flared using Gates Glidden burs. Samples were randomly divided into 5 experimental groups of 10 each. In group I, GT files, Profile 04 and Quantec #9 and #10 files were used. In Group II Lightspeed was used instead of Quantec. In Group III, Orifice shaper, Profile .06 series and Lightspeed were used. In Group IV, Quantec #9 and #10 files were used instead of Lightspeed. In Group V, the GT file and the Profile .04 series were used to prepare the entire canal length. All tooth samples were cut at 1 mm, 3 mm and 5 mm from the apex and were examined under the microscope.
RESULTS
Groups II and III (Lightspeed) showed a more circular preparation in the apical 1mm samples than the groups that used Quantec (Group I & IV) or GT files and Profile .04 series.(Group V)(p < 0.05) There was no significant difference statistically among the apical 3, 5 mm samples. In 5 mm samples, most of the samples showed complete circularity and none of them showed irregular shape.
CONCLUSIONS
Lightspeed showed circular preparation at apical 1 mm more frequently than other instruments used in this study. However only 35% of samples showed circularity even in the Lightspeed Group which were enlarged 3 ISO size from the initial apical binding file (IAF) size. So it must be considered that enlarging 3 ISO size isn't enough to make round preparation.

Keyword

Apical sealing; Circular apical preparation; GT file; Lightspeed; Profile; Quantec

MeSH Terms

Nickel
Titanium
Tooth
Nickel
Titanium

Figure

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  Figure 1 Overview of canal preparation methods in this experiment.

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  Figure 2 Photos from cross-section specimens. These specimens were sectioned 1, 3, 5 mm from the apex using Buehler saw (IsoMet 1000 Precision Saw, buehler, Lake Bluff, IL, USA) and examined under the microscope (×35). Circularity was scored. Score 1 was a complete circle, 2 was an incomplete circle, and 3 was an irregular shape.

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  Figure 3 Photos from cross-section specimens at apical 1 mm level. (a) was a complete circle, (b) was an incomplete circle, and (c) was an irregular shape.

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  Figure 4 Comparison of circularity at apical 1 mm level for instrumentation modalities of 3 experimental groups.

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  Figure 5 Comparison of circularity at apical 3 mm level for instrumentation modalities of 3 experimental groups.

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  Figure 6 Comparison of circularity at apical 5 mm level for instrumentation modalities of 3 experimental groups.

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