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

Article information

Restor Dent Endod. 2011;36(4):300-305

Publication date (electronic) : 2011 July 31

doi : https://doi.org/10.5395/JKACD.2011.36.4.300

Yooseok Shin, DDS, MSD , Su-Jung Shin, DDS, MSD , Minju Song, DDS, MSD , Euiseong Kim, DDS, MSD, PhD

Department of Conservative Dentistry, Microscope Center, Yonsei University, Seoul, Korea.

Correspondence to Euiseong Kim, DDS, MSD, PhD. Professor, Department of Conservative Dentistry, College of Dentistry, Yonsei University, 250 Seongsanno, Seodaemun-gu, Seoul, Korea 120-752. TEL, +82-2-2228-3145; FAX, +82-2-313-7575; andyendo@yuhs.ac

Received 2011 April 29; Revised 2011 July 09; Accepted 2011 July 10.

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.

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

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Article information Continued

Figure 1

Overview of canal preparation methods in this experiment.

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.

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.

Figure 4

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

Figure 5

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

Figure 6

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