We observed statistically significant differences (P = .0001) in the levels of MMP-8 between the irreversible pulpitis and the healthy pulp groups (Rho = 0.8277, P = .0001), and the reversible pulpitis group (Rho = 0.7646, P = .0001), with a higher average concentration of MMP-8 in the irreversible pulpitis group. Here, MMP8 is linked to pulpitis.