RESUMO
Introduction: For successful endodontic therapy it is vital to have thorough knowledge of morphology of the root canal system and its variations besides proficient aseptic intraoperative condition. Mandibular second premolars are usually single rooted tooth with single root canal system. The incidence of the number of roots and the number of canals varies greatly in the literature. Methods and Results: This case report describes an unusual case of mandibular second premolar with two roots and five root canals. This was confirmed by radiographs, dentascan and dental operating microscope (DOM), and was successfully treated using K files system, guttapercha and AH plus sealer in lateral condensation manner. Conclusion: The clinical significance of this case report is that the precise awareness about the aberrant morphologies of the root canal system can only be appreciated when advanced radiographic techniques, magnification and illumination are used to treat such type of cases.