Restor Dent Endod.  2013 Feb;38(1):26-30. 10.5395/rde.2013.38.1.26.

Apical foramen morphology according to the length of merged canal at the apex

• Kim HH
• Min JB
• Hwang HK

• KMID: 1995473
• DOI: http://doi.org/10.5395/rde.2013.38.1.26

Abstract

OBJECTIVES
The aim of this study was to investigate the relationship between the apical foramen morphology and the length of merged canal at the apex in type II root canal system.
MATERIALS AND METHODS
This study included intact extracted maxillary and mandibular human premolars (n = 20) with fully formed roots without any visible signs of external resorption. The root segments were obtained by removing the crown 1 mm beneath the cementum-enamel junction (CEJ) using a rotary diamond disk. The distance between the file tip and merged point of joining two canals was defined as Lj. The roots were carefully sectioned at 1 mm from the apex by a slow-speed water-cooled diamond saw. All cross sections were examined under the microscope at x50 magnification and photographed to estimate the shape of the apical foramen. The longest and the shortest diameter of apical foramen was measured using ImageJ program (1.44p, National Institutes of Health). Correlation coefficient was calculated to identify the link between Lj and the apical foramen shape by Pearson's correlation.
RESULTS
The average value of Lj was 3.74 mm. The average of proportion (P), estimated by dividing the longest diameter into the shortest diameter of the apical foramen, was 3.64. This study showed a significant negative correlation between P and Lj (p < 0.05).
CONCLUSIONS
As Lj gets longer, the apical foramen becomes more ovally shaped. Likewise, as it gets shorter, the apical foramen becomes more flat shaped.

Keyword

Apical foramen; Type II root canal system

MeSH Terms

Academies and Institutes
Aluminum Hydroxide
Bicuspid
Carbonates
Crowns
Dental Pulp Cavity
Diamond
Humans
Tooth Apex
Aluminum Hydroxide
Carbonates
Diamond

Figure

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  Figure 1 The distance between the file tip and merging point of two joining canals (Lj) on radiograph.

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  Figure 2 The apical foramen shape (×50).

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