Questions on the new classification of periodontal and preimplantation diseases

Armitage’s classification of periodontal diseases came to practice in the 1999 Periodontal Workshop and has been diligently followed ever since.1 In the last two decades, knowledge of periodontal diseases has increased rapidly. A new class of the disease has also been added to the classification of periodontal diseases, with similar pathogenesis, but it arises around dental implants. There was a compelling need to understand and categorize this information about the principles of evidence-based dentistry and reach a worldwide consensus. To achieve this goal, the American Academy of Periodontology and the European Periodontology Federation convened a meeting in November 2017 to organize a workshop entitled “Classification of Periodontal and Periimplant Diseases” in June 2018 in both journals of Periodontology: a leading journal of the American Academy of Periodontology and the Journal of Clinical Periodontology, a leading journal of the European Periodontology Federation, with 19 review articles and four consensus reports.2 Since the diagnosis of patients’ periodontal status is the basis of dental examinations, this classification has affected the entire dental science and community. To begin with, periodontal health was defined as the absence of signs of inflammation indicated by <10% of sites with bleeding on probing and probing depths <3 mm. Gingivitis was defined as a reversible inflammation indicated by bleeding on probing in more than 10% of sites, with probing depths of <3 mm. Gingivitis was further divided depending on whether it is present in an intact periodontium, in a reduced periodontium (e.g., gingival recession cases), or in a successfully treated periodontally stable patient. The primary etiologic factor for the above conditions was considered to be dental biofilm. In contrast, a separate category was assigned to non-dental plaque-induced gingival diseases like viral, bacterial, autoimmune diseases, or numerous other conditions affecting the gingiva not induced by dental plaque.