The subject of periodontology considers a broad range of issues that represent contemporary controversies in the discipline. Controversies exist in various subjects like classification of periodontal diseases, pathogenesis of periodontal diseases including the role of occlusion, periodontal-endodontic controversy, lasers in periodontics and many more. A sincere attempt has been made in giving holistic conclusions to these various controversies through this book.However, the conclusions drawn are not the final word on these topics of discussion and debate.