Four‐Octyl Itaconate Alleviates <i>Enterococcus faecalis</i> ‐Induced Apical Periodontitis by Inhibiting Macrophage <scp>M1</scp> Polarisation

4-OI inhibits E. faecalis-induced macrophage M1 polarisation probably by activating the Nrf2 antioxidant system, thereby suppressing experimental apical periodontitis in mice. These findings suggest that 4-OI possesses great potential as a valuable adjunct to conventional root canal therapy in the management of E. faecalis-related refractory apical periodontitis.