MMP-8 (or collagenase 2), as a prominent collagenase, is involved in the degradation of the extracellular matrix and basement membrane.25–27 MMPs are controlled and inhibited by specific tissue inhibitors, mainly TIMP-1, and a shift in the balance between MMP-8 and TIMP-1 can lead to the progression of periodontal diseases.28,29 In this study, our results showed that the MMP-8 concentration and the MMP-8/TIMP-1 ratio in GCF decreased following N-M3 extraction: MMP-8 concentration was significantly reduced at T2, and the MMP-8/TIMP-1 ratio was significantly reduced at T1 (Fig. 2b, d). The gene discussed is MMP8; the disease is periodontal disorder.