Mandibular Central and Lateral Incisor

Central and lateral incisors are so similar in shape, configuration, and dimension that one description will hold true for both.

The mandibular incisors have only one root, which is narrow mesio-distally but relatively wide labio-lingually, and may have a distal and/or lingual curvature. The canal configuration may be of Type I, II, or III, in that order of frequency. The labio-lingual section reveals the great width of the pulp canal which allows room for two separate canals or one wide canal with an island of dentin in the middle. A mesio-distal section shows that the pulp canal is quite narrow and is particularly constricted in the root portion of the tooth, with both the root and the canal taking a gradual distal curve. Because of this narrow mesio-distal dimension, the access preparation must be extremely precise to avoid root perforation.

A cross section in the cervical area demonstrates that the canal is a long, thin oval, very constricted mesiodistally. Because of the implication of canal configuration, the access preparation suggested is oval but is wide labio-lingually to allow for proper instrumentation.