Dental implant has been scientifically documented and clinically used for more than fifty years. Treatment plans and surgical procedures of dental implants have been closely related to periodontology. A comprehensive periodontal exam is a critical part in a diagnosis and treatment plan. Multidisciplinary approaches for implant treatment plans will achieve optimal clinical results and have begun to increase in use. Classic periodontal concepts, such as biological width and attached gingival, also apply to the bone and soft tissue around dental implants. Similar to periodontal maintenance, the long-term success of dental implants depends on regular maintenance programs. Therefore, periodontology is the base of dental implant treatment plans and surgical procedures. Understanding of periodontology is important for everyone involved in dental implant treatments.