The Diagnosis of Peri-implant Tissue Disease : A New Classification of Peri-implantitis and Remodeling of Surrounding Bone after Dental Implant Placement

• Published in: Journal of Japanese Society of Oral Implantology Vol. 36; no. 2; pp. 89 - 99
• Main Authors: SAKAMOTO, Takashi, UESUGI, Satoshi, IIDA, Tsutomu
• Format: Journal Article
• Language: Japanese
• Published: Japanese Society of Oral Implantology 30.06.2023
• Subjects: bone remodeling; microgap; peri-implantitis; placement depth; platform switching
• ISSN: 0914-6695; 2187-9117
• DOI: 10.11237/jsoi.36.89

A new classification of periodontal disease based on a joint American Academy of Periodontology (AAP) and European Federation of Periodontology (EFP) workshop was published in 2018. The diagnosis of peri-implantitis according to the new criteria is based on bleeding on probing (BOP), probing pocket depth (PPD), and bone resorption on a radiographic examination. It was specified that the diagnosis is based on an increase in PPD, an increase in bone resorption on X-ray, and BOP or drainage of pus compared with the results of an examination after placement of the implant superstructure. In the absence of previous examination data, the criteria were positive BOP, PPD ≥6 mm, and bone resorption ≥3 mm, with the caveat that BOP should be performed at ≤25 g or at an equally low pressure. Increased bone resorption on a radiographic examination was described as bone resorption beyond the initial bone remodeling. This remodeling is bone resorption that occurs within six months to one year after the upper portion of the implant has been exposed to the oral cavity, such as after abutment placement following secondary surgery in two-stage implants. This is a normal bone resorption image according to biologic width or supracrestal tissue attachment. By using a non-matching morse taper type abutment with a smaller diameter than the implant, the vertical epithelial descent can be reduced by changing the direction of the epithelial descent to the horizontal direction. This non-matching morse taper type is called platform switching. To avoid mistaking this normal remodeling for bone resorption due to peri-implantitis, a clear distinction was made. Factors that influence bone remodeling are the connection pattern of the implant-abutment junction and the depth of implant placement. The vertical position of the microgap between the implant and the superstructure is important.