A complete endodontic diagnosis must include both a pulpal and a periapical diagnosis for each tooth evaluated before endodontic treatment can be rendered. It is much like going on a reconnaissance mission, gathering as much information as possible and not relying on a single isolated piece of this information before endodontic treatment is provided. This presentation will take the participant on a diagnostic journey to be able to come to a proper decision systematically and logically on whether the patient’s symptoms are odontogenic in origin or coming from another source. In addition, the most common endodontic emergencies will be discussed and how best to treat them. Learning Objectives 1) To predictably carry out pulpal and periapical tests in a logical and efficient sequence 2) To make a pulp and periapical diagnosis according to the American Association of Endodontists classification 3) To discuss and present cases of Endo/Perio significance, differential diagnosis and treatment. 4) To be able to treat the most common endodontic emergencies