Influence of locally delivered doxycycline on the clinical and molecular inflammatory status of intrabony defects prior to periodontal regeneration: A double-blind randomized controlled trial.

Objectives: To test the effect of locally delivered doxycycline (DOX) administered 2 weeks prior to minimally invasive periodontal regeneration in terms of presurgical inflammatory status and cytokine expression profile in the gingival crevicular fluid (GCF). Secondary aim was to assess the early wound healing index (EHI) at 2 weeks after surgery.
Background: It is hypothesized that healing after periodontal regeneration is dependent on preoperative soft tissue condition, and that local antibiotics may improve the site-specific inflammatory status at short time.
Methods: Sites associated with periodontal intrabony defects requiring regenerative surgery and showing bleeding on probing (BoP) were included. At T0, experimental sites were randomly treated with subgingival instrumentation with or without topic DOX application. After 2 weeks (T1), defects were approached by means of minimally invasive surgical technique. GCF was sampled at both T0 and T1 for inflammatory biomarker analysis. Two weeks after surgery, the EHI was evaluated (T2).
Results: Forty-four patients were included. At T1, the number of BoP+ sites was statistically significantly less in the test group (27.3% vs. 72.7%; p < .01). The total amount of interleukin (IL)-1β (p < .001), matrix-metalloproteinases (MMP)-8 (p < .001), and MMP-9 (p = .010) in the GCF significantly decreased in the test group at T1, with relevant differences compared to controls. At T2, the EHI had an average value of 1.45 ± 0.86 in the test group while in the control, it was 2.31 ± 1.43 (p = .027). A statistically significantly positive correlation was observed between the amount of IL-1β and MMP-9 and EHI scores.
Conclusions: Within the limitations of this study, sites treated with DOX showed improved clinical and molecular inflammatory parameters before surgery, as well as soft tissue healing 2 weeks after surgery.
(© 2023 The Authors. Journal of Periodontal Research published by John Wiley & Sons Ltd.)