Mandibular First Bicuspid

The mandibular first premolar may cause great problems during treatment because of the relatively frequent existence of a bifurcated canal dividing in the middle or apical third (Type IV) into a buccal and a lingual branch. These teeth usually have one root and one canal, but Type II or IV configurations may be present. Rarely, a condition of two separate roots, each with one canal is present.

In cervical cross section, the canal is slightly oval and thus the access cavity has the same shape. When divided canals are present, the entry must be widened buccolingually.  In case of Type IV canals, it is often difficult to locate the lingual canal. The buccal canal must be approached from the lingual direction and, conversely the lingual canal from the buccal.