Three-session non-surgical therapy stabilizes microbiological and biochemical responses in patients with stage III/IV grade C periodontitis: a randomized clinical trial.

OBJECTIVES

Management of Stage III/IV Grade C periodontitis (SIII/IVGrC) remains challenging, and the optimal non-surgical approach has not been clearly established. This randomized controlled clinical trial aimed to compare the clinical, biochemical, and microbiological outcomes of single-session versus three-session non-surgical periodontal therapy in patients with SIII/IVGrC.

MATERIALS AND

METHODS

Thirty-three patients with SIII/IVGrC were randomly allocated to single-session (SSTG, n = 16) or three-session (TSTG, n = 17) therapy. Fifteen periodontally healthy individuals served as controls. Probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), and plaque index (PI) were recorded at baseline and at 1, 3, and 6 months. The primary outcome was the change in probing depth, while secondary outcomes included changes in CAL, BOP, and selected microbiological and biochemical parameters. Gingival crevicular fluid (GCF) levels of IL-1β, IL-6, clusterin, cystatin C, and osteocalcin were quantified, and subgingival microbiota -including Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, and Aggregatibacter actinomycetemcomitans- were analyzed using checkerboard DNA-DNA hybridization.

RESULTS

Both treatment groups showed significant clinical improvements over 6 months (p < 0.05), with no intergroup differences in PD, CAL, BOP, or PI. At baseline, GCF IL-1β and cystatin C were elevated in SIII/IVGrC compared to controls (p < 0.05). TSTG achieved greater reductions in IL-1β (3 and 6 months) and cystatin C (3 months) and demonstrated more pronounced decreases in red and orange complex species than SSTG (p < 0.05).

CONCLUSIONS

Three-session therapy provided superior biochemical and microbiological improvements compared with single-session therapy, indicating a more stabilizing effect on host-microbe interactions.

CLINICAL RELEVANCE: For patients with SIII/IVGrC periodontitis, three-session therapy may offer enhanced modulation of inflammatory and microbial parameters while achieving comparable clinical outcomes to single-session therapy.