Change in clinical parameters after subgingival instrumentation for the treatment of periodontitis and timing of periodontal re‐evaluation: A systematic review and meta‐analysis

Aim: To evaluate the changes in periodontal parameters (reduction in probing pocket depth [PPD], gain in clinical attachment level [CAL] and reduction in full-mouth bleeding on probing [BoP]) after subgingival instrumentation of periodontal pockets at different time points in systemically healthy patients suffering from periodontitis. Materials and methods: Four databases were searched for RCTs that carried out subgingival instrumentation in periodontal pockets and evaluated PPD at a minimum of two consecutive time points other than baseline. The analysis was conducted for both all pocket depths and stratified for initially shallow (4-5 mm) and deep (≥6 mm) pockets and data were extracted for various time points, 1-2, 3-4 and 5-6 months. Weighted mean effects (WMEs) were calculated with 95% confidence interval (CI) and predictive intervals were calculated. Results: Twenty-nine RCTs were identified, and all of them were included in the meta-analysis. The results showed that for both shallow and deep pockets there was a small though clinically meaningful change between 1- to 2-month and 3- to 4-month time points and between these and 5-6 months. Conclusions: In systemically healthy patients, the greater part of reduction in PPD and gain in CAL occurs within the first 1-2 months after subgingival instrumentation. However, additional benefits in terms of pocket depth reduction occur beyond these early time points.