Journal List > Restor Dent Endod > v.37(2) > 1089992

Park, Lee, and Hwang: An evaluation of the accuracy of Root ZX according to the conditions of major apical foramen

Abstract

Objectives

The purpose of this study was to assess the accuracy of Root ZX (J. Morita Corp.) according to the location of major foramen and open apex.

Materials and Methods

81 mandibular premolars with mature apices were selected. After access preparation, 27 teeth were instrumented to simulate open apices. 54 teeth were classified according to location of major foramen under surgical microscope (×16). The file was fixed at the location of apical constriction by Root ZX using glass ionomer cement. The apical 4 mm of the apex was exposed and photo was taken and the distance from file tip to the major foramen was measured by calibrating metal ruler on graph paper. The results were statistically analyzed using ANOVA and Scheffe test at p < 0.05 level.

Results

Mean distance from file tip to major foramen was 0.308 mm in Tip foramen group (I), 0.519 mm in Lateral foramen group (II) and 0.932 mm in open apex group (III). Root ZX located apical constriction accurately within ± 0.5 mm in group I of 85.71%, in group II of 59.09%, and in group III of 33.33%. There was a statistically significant difference between group I and III (p < 0.05).

Conclusion

Root ZX located apical constriction accurately regardless of location of major foramen. However, Root ZX couldn't find it in open apex. Clinicians have to use a combination of methods to determine an appropriate working length at open apex. It may be more successful than relying on just electronic apex locator.

Figures and Tables

Figure 1
An open apex model. (a) The canals were instrumented with a #2 Peeso reamer to the actual length; (b) A divergent open apex was prepared by retrograde apical preparation with a .04/50 K3 file inserted to the length of the cutting blade; (c) Simulated open apex model.
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Figure 2
Tip foramen (group I), in which major foramen is located at the tip along the main axis of root. File was fixed in the position and the distance from file tip to major foramen was measured (×25).
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Figure 3
Lateral foramen (group II), in which major foramen deviates from the main axis of root. File was fixed in the position and the distance from file tip to major foramen was measured (×25).
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Figure 4
Simulated open apex (group III). File was fixed in the position and the distance from file tip to major foramen was measured (×25).
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Table 1
Distance from file tip to major foramen (mm)
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*A significant difference was found between group I and group III (p < 0.05).

SD, standard deviation.

Table 2
Position of file tip relative to major foramen
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*Negative value indicates file tip short from major foramen.

d, distance from file tip to major foramen.

Notes

No potential conflict of interest relevant to this article was reported.

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