Minocycline hydrochloride plus metronidazole versus metronidazole alone for peri-implantitis: a comparative study

To evaluate the efficacy of minocycline hydrochloride combined with metronidazole versus metronidazole alone in treating peri-implantitis and their impact on specific inflammatory markers.

A retrospective review was undertaken of 107 patients with peri-implantitis from January 2018 to January 2021. Patients were treated either with metronidazole alone (Con group, n = 57) or with additional minocycline hydrochloride (Exp group, n = 50). Inflammatory markers, including interleukin-6 (IL-6), interleukin-1 beta (IL-1β), tumor necrosis factor alpha (TNF-α), and matrix metalloproteinase-8 (MMP-8) were determined before and after treatment. Clinical outcomes were determined using the plaque index (PLI), gingival sulcus bleeding index (SBI), and periodontal probing depth (PD). Furthermore, receiver operator characteristic (ROC) curves analyzed the clinical relevance of the markers. Logistic regression was conducted to analyze the risk factors affecting efficacy in patients.

The Exp group exhibited more favorable clinical outcomes and showed lower levels of IL-6, IL-1β, TNF-α, and MMP-8 than the Con group. IL-1β, TNF-α, and MMP-8 levels were significantly correlated with treatment success (P < 0.05), but IL-6 was not (P > 0.05). The ROC curves for IL-1β and TNF-α significantly outperformed those for IL-6 and MMP-8 (P < 0.05). Logistic regression analysis showed that only IL-1β and TNF-α were independent risk factors affecting efficacy in patients.

Combining minocycline hydrochloride with metronidazole yields better outcomes for peri-implantitis compared to metronidazole alone. Of the factors analyzed, only IL-1β and TNF-α emerged as dependable independent efficacy indicators.