Comparison of Periodontitis Diagnoses According to 1999 and 2017 Classifications: An Original Article

Objectives: Classification systems of periodontitis have changed several times over the past 30 years as new information gathered about the pathophysiology of the disease rendered previous systems inadequate for classifying the diagnoses of all patients. Although the 1999 classification system was widely used in clinical practice and scientific studies, it had significant limitations leading to the reclassification introduced in 2017. In this context, the aim of this study is to evaluate how individuals diagnosed with periodontitis under the 1999 system were reclassified according to the 2017 system.Materials and Methods: Participants diagnosed with periodontitis according to 1999 classification and who had not received periodontal treatment in the last six months were included in the study. The patient assessment procedure consisted of a comprehensive periodontal diagnosis through periodontal charting and full-mouth radiography.Results: A total of 315 subjects (133 males and 182 females) were included in the study. According to the new classifications, 42 patients (17.94%) previously diagnosed with generalized chronic periodontitis according to 1999 classifications, were now classified as healthy with reduced periodontium, and 11 (4.7%) patients were classified as gingival inflammation with reduced periodontium. 63 (26.92%) patients were classified as SIII-GC and 33 patients (14.14%) as SIV-GC.Conclusions: The new classification system is based on not only disease severity but also the dimensions of an individual’s disease which include complexity and risk factors.