In recent years, the quality of life of patients who have lost teeth because of severe periodontitis has been improved due to the increasing popularity of implant therapy. However, the biggest concern after implant treatment for patients who have suffered from severe periodontitis is the development of peri-implantitis. Long-term follow-up studies have shown that the incidence of peri-implantitis is higher among patients with a history of periodontitis compared to those without. Having a history of periodontitis, as well as smoking habit, is considered to be a risk factor for peri-implantitis.
When providing implant therapy in a patient with severe periodontitis, the following characteristics of the patient need to be considered：1) deep periodontal pockets and infra-bony defects in the teeth, 2) significant alveolar bone loss of the edentulous ridge, 3) an increased mobility of residual teeth resulting from a reduction of supporting bones, 4) the possibility of malocclusion resulting from pathological tooth migration, which exacerbates periodontal disease, and 5) the possibility of tooth loss resulting from periodontal disease that has progressed due to malocclusion.
A combination of these five characteristics could aggravate the decline in ability to cleanse periodontal tissues and peri-implant tissues, resulting in traumatic forces to implant prostheses and natural teeth. Therefore, when providing implant therapy to patients with severe periodontitis, in order to gain long-term stability after treatment, it is particularly necessary to make a detailed diagnosis and prepare a comprehensive treatment plan. Such a treatment plan must be followed by distinct periodontal treatment, reconstruction of hard and soft tissues around the implants, and establishment of a stable occlusal relationship.
