mandibular second premolar with four canals

A mandibular second premolar with four canals is an interesting example of anatomic variations. this report describes a case of a mandibular second premolar with three roots and four canals (one mesiobuccal, two distobuccal and one lingual). the canals were prepared using k-files and irrigated with naocl (5.25%) and normal saline as the final irrigant. the canals were filled laterally with gutta percha and ah26 sealer (de trey, dentsply, switzerland). this case shows a rare anatomic configuration and points out the importance of looking for additional canals.