Restor Dent Endod.  2021 Feb;46(1):e12. 10.5395/rde.2021.46.e12.

The effect of different confluence confirmation strategies on the obturation of Vertucci type II canal: micro-CT analysis

• Do S
• Seo MS

• KMID: 2548047
• DOI: http://doi.org/10.5395/rde.2021.46.e12

Abstract

Objectives
The present study aims to compare the obturation quality of 2 confluence confirmation techniques in artificial maxillary first premolars showing Vertucci type II root canal configuration.
Materials and Methods
Thirty artificial maxillary premolars having Vertucci type II root canal configuration were made. They were divided into 3 groups according to the confluence confirmation technique as follows. Gutta-percha indentation (GPI) group (confluence confirmation using a gutta-percha cone and a K file); electronic apex locator (EAL) group (confluence confirmation using K files and EAL); and no confluence detection (NCD) group. In the GPI group and the EAL group, shaping and obturation were performed with the modified working length (WL). In the NCD group, shaping was performed without WL adjustment and obturation was carried out with an adjusted master cone. Micro-computed tomography was used before preparation and after obturation to calculate the percentage of gutta-percha occupied volume (%GPv) and the volume increase in the apical 4 mm. Data were analyzed using 1-way analysis of variance and post hoc Tukey's test.
Results
Statistically significant difference was not found in terms of the %GPv from the apex to apical 4 mm. However, the NCD group showed a statistically significant volume increase compared with the EAL group (p < 0.05).
Conclusions
In terms of gutta-percha occupied volume, no significant difference was observed among the 3 groups. Confluence confirmation using an EAL in teeth with Vertucci type II configuration showed less volume increase during canal shaping compared with no confluence confirmation.

Keyword

Artificial teeth; Confluence; Micro computed tomography; Obturation

Figure

• 

  Figure 1 Artificial maxillary premolar sample with Vertucci type II canal configuration. Taper of 0.02, apical foramen size of #15, 2 canals merged at 3 mm from the apex. Zone of confluence was from apical 2 mm to apical 4 mm.

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  Figure 2 Schematic drawing of the confluence confirmation strategies. Electronic apex locator (EAL) group: (A) Confirmation of confluence point by using EAL; Gutta-percha indentation (GPI) group: (B) Confirmation of confluence point by using GPI.

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  Figure 3 Micro-computed tomography images of the representative specimen (3 mm from apex). (A) Two-dimensional cross sectional virtual slice; (B) Region of interest selection; (C) Representative binarized images to distinguish gutta-percha and voids. The voids, connection, and gutta-percha are marked by an arrow. The image shows cross section of 1) the gutta-percha indentation group, 2) the electronic apex locator group, 3) the no confluence detection group.

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