Furcation involvement exits when periodontal disease has caused resorption of bone into the bi- or trifurcation area of a multi-rooted teeth. The access to the furcation area is difficult both for the dentist and patient, and their treatment constitutes an enormous challenge. The treatment of teeth with furcation involvement ranges from thorough debridement to regenerative procedures and, if the lesion progresses, to extraction. In this book the various factors which causes furcation involvement, aids used in the diagnosis, prognosis and various treatments are describe. Novel treatment modalities compel the therapist to acquire the necessary data and to correctly interpret the respective observations.Not only technical skills of the therapist is required but also understanding, confidence and compliance of the patient.