Abstract
The new classification system of periodontal diseases, introduced in 2017, aims to provide more precise diagnostic criteria for identifying and classifying periodontitis. It defines periodontal disease based on staging, grading and extent, facilitating a more accurate approach for general dentists and periodontists. AIM: The aim of this study was to establish the inter-observer agreement and diagnostic accuracy among three groups with different levels of education and experience in dentistry in assigning stages, grades and extent of periodontitis using the 2017 AAP-EFP classification system. MATERIALS AND METHOD: The study involved 32 participants divided into three groups: Group 1-dental students (n=12), Group 2-dentists with up to 3 years' experience (n=10), and Group 3-general dentists with more than 4 years' clinical experience (n=10). Twelve periodontitis cases were evaluated by all participants, who classified each case by stage, grade and extent. The evaluations were compared with the gold standard provided by a panel of expert periodontists. Statistical analysis, including Fleiss' kappa and chi-square tests, was performed to assess agreement and diagnostic accuracy. RESULTS: Significant differences were observed in stage classification, with students and recent graduates more likely to underestimate the severity of the disease, while experienced dentists tended to overestimate it. No significant differences were found in grade and extent classifications. Diagnostic accuracy was comparable across all groups, but students showed slightly higher agreement with the gold standard compared to other groups. CONCLUSIONS: The 2017 AAP-EFP classification system can be applied by both general dentists and dental students, but further clinical practice is needed to improve diagnostic accuracy. Misclassification tendencies, such as over- or underestimation of disease severity, highlight the need for additional training and familiarity with the system.