Aim: To report and discuss the endodontic management of maxillary and mandibular premolars presenting complex root canal anatomy.

Background: Premolars exhibit significant anatomical variability, which may lead to endodontic failure when additional canals are not identified and treated. Successful root canal therapy relies on accurate diagnosis, appropriate access cavity design, thorough chemo-mechanical preparation, and three- dimensional obturation. Therefore, careful assessment of root canal morphology is essential to ensure complete debridement and filling of the entire canal system.

Case Presentation: Five cases are presented. Two cases discussed the endodontic treatment and retreatment of maxillary first premolars with three canals. The other three cases concerned mandibular first premolars with two, three and four canals.

In all cases, it was the in-depth radiographic analysis, combined with adapted access cavity design and meticulous canalexploration under magnification (loupes). Proper chemo-mechanical preparation and three-dimensional filling of the entire root canal system were then performed.

Conclusion: Maxillary and mandibular premolars present complex and highly variable canal configurations that may compromise treatment outcomes if not properly identified. A thorough understanding of root canal anatomy, combined with appropriate diagnostic and clinical strategies, is essential for achieving successful endodontic outcomes.

Clinical significance: These cases highlight the importance of systematic clinical and radiographic evaluation in detecting additional canals and support a structured approach to managing premolars with complex root canal anatomy.