Metformin reverses periodontal destruction caused by experimental periodontitis by inhibiting interleukin‐1β activity

Periodontitis is a serious gum disease that destroys the structures that support the teeth, such as ligaments and bone. While current treatments focus on preventing further damage, little progress has been made in achieving complete restoration of damaged tissue. In this study, we investigated whether metformin, a common diabetes drug, could help repair periodontal tissue. Using a mouse model of periodontitis, we removed ligatures placed around the teeth to allow healing, followed by metformin treatment. Our results showed that metformin promoted the repair of key tissues such as the periodontal ligament, alveolar bone, and cementum. An important observation in this study is the persistence of inflammatory activity during periodontitis resolution, where prolonged inflammation, driven by molecules such as interleukin-1β (IL-1β), appears to hinder tissue recovery. Metformin was found to counteract prolonged inflammation by reducing IL-1β activity, allowing tissue to heal. It also restored the function of bone-forming cells and limited the activity of bone-resorbing cells. These results suggest that metformin may be a promising therapy for promoting periodontal tissue repair by both controlling inflammation and enhancing cellular activity critical for tissue restoration.