D13

#13. The upper canine is the longest tooth, and occasionally longer files of 28 or 31 mm lengths are needed for the root canal treatment. It always has only one root canal, which usually has an oval cross-section. The root canal is typically quite large, but often the few most apical millimeters before the foramen are much narrower. This may lead to incorrect working length if the position of the apical constriction is determined only with tactile sensation with the file and fingertips. Like the upper lateral incisor, the apical canal in the upper canine may have a pronounced curve, usually either distally or labially, although not quite so frequently. Awareness of the possibility of apical curvatures and careful assessment of root canal anatomy are essential in order to avoid complications in therapy.

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