[Introduction and interpretation of the European Federation of Periodontology S3 level clinical practice guideline for treatment of periodontitis].

2018 international classification of periodontal and implant diseases relates the classifications with the approaches of prevention and treatment based on the stages and grades of disease. European Federation of Periodontology (EFP) evaluated the available evidences following the methodological guidance of the Association of Scientific Medical Societies in Germany and the Grading of Recommendations Assessment, Development and Evaluation (GRADE), and published the EFP S3 level clinical practice guideline for the treatment of stage Ⅰ-Ⅲ and Ⅳ periodontitis in 2020 and 2022, respectively. The present manuscript gives introduction and interpretation based on the EFP S3 level clinical practice guideline and Chinese national conditions. On the base of the diagnostic key points of staging and grading, it introduces in detail the step treatment procedures of stageⅠ-Ⅲ periodontitis as well as the multi-disciplinary treatment procedures of stage Ⅳ periodontitis, compares the similarities and differences between the step and phase procedures, and then proposes a strategy for determining the recall interval more suitable for Chinese clinicians. The present manuscript aims to help dentists to learn and grasp the key points more quickly and accurately on the clinical application of the guideline and to assist them in making the optimal treatment plans after judging and evaluating the specific clinical circumstances, so as to maximize the chances of favorable outcome.