Maxillary Second Molar

The maxillary second molar usually has similar canal configuration combinations as the first molar has: two buccal roots and one palatal root. The disto-buccal and palatal roots each have one canal, but the mesio-buccal may have two canals, with either the canals merging short of the apex (Type II) or remaining separate and distinct (Type III). The access cavity is prepared in the same manner and shape as for the first molar, except that the buccal side of the quadrilateral is not as long, since the buccal canals are usually found closer together. In second molars with sclerotic canals or those that have crowns compressed mesio-distally, the disto-buccal orifice may be located towards the centre of the access than near the mesio-buccal orifice.

A differing type of root configuration may also be present in the maxillary second molar that contains two roots, one buccal and one palatal. In still another modification these two roots merge near the apex.