Effective periodontal and peri-implant therapies are based on the fundamentals: formulation of a correct diagnosis, accurate treatment planning, precision in clinical treatment, and appropriate follow-up. This beautifully illustrated text addres- ses the nonsurgical and surgical therapies that can ensure the essential stability of the hard and soft tissues. Emphasis is placed on understanding the long-term behaviors of soft tissue and bone as well as on achieving successful long-term results.