Papilla preservation flap surgery and endoscope-assisted subgingival debridement for Step 3 therapy: A 12-month pilot study on subgingival microbial community dynamics in deep periodontal pockets

Abstract

<p>Objectives: This study aimed to assess subgingival microbial changes following papilla preservation flap surgery (PPFS) or endoscope-assisted subgingival debridement (EASD) in patients with residual periodontal intrabony defects requiring Step 3 therapy. Methods: Nineteen periodontitis participants requiring Step 3 periodontal therapy were randomly allocated to either the PPFS (n = 11) or EASD (n = 8) treatment group and were conveniently sampled. Subgingival plaque samples were collected at baseline, days 3, 7, 14, and months 1, 3, 6, 9, and 12 post-treatment. DNA extraction and 16S rRNA sequencing were used to analyze microbial communities through bioinformatics tools, assessing diversity and differential abundance. Results: Both treatments were effective, with no significant difference in clinical outcomes. Pocket resolution was achieved in 100% of PPFS sites and 87.5% of EASD sites. The overall microbiome composition was similar between groups. However, microbial diversity dynamics differed: PPFS exhibited stable shifts over time (PERMANOVA, p = 0.004), whereas EASD showed more variability in species richness and abundance, indicating less predictable microbial reorganization (Procrustes, p = 0.030). Notably, Fusobacterium nucleatum subsp. vincentii/Fretibacterium fastidiosum and Treponema socranskii were significantly associated with bleeding on probing/probing pocket depth, respectively (p < 0.05). Conclusions: Both PPFS and EASD effectively treat residual intrabony defects, with PPFS showing more consistent microbial modulation. This 12-month pilot study offers new insights into the changes in microbiota following surgical and minimally invasive periodontal therapies, highlighting potential microbial biomarkers associated with clinical outcomes. Clinical Significance: This 12-month study, for the first time, profiled the subgingival microbiota over the management of residual intrabony defects using either PPFS or EASD in Step 3 therapy. The study also revealed possible associations between specific microbes and clinical parameters during the post-operative period, which warranted further investigation. <br></p>