Endodontic and periodontal lesions can manifest identical symptoms despite originating from separate pathogens, and traditional classification has reinforced etiological imprecision in both diagnosis and treatment. Supported by a thorough analysis of the diagnostic, etiopathogenic, and clinical factors, the author of this succinct book proposes new terminology and a simplified classification of endo-periodontal lesions that shed light on an ambiguous pathologic situation that is often misinterpreted in clinical practice. Step-by-step, the reader is guided through a systematic differential diagnosis in order to distinguish the signs and symptoms arising from each etiology that determine how to proceed with appropriate treatment. The author presents an interdisciplinary approach to treatment planning as well as predictable clinical protocols to ensure success in treatment. Abundant case documentation illustrates the close connection between the dental pulp and the periodontium and shows the variety of clinical situations in which this dual-natured pathology can present. An essential primer to clarify diagnosis and treatment of endo-periodontal lesions.