The following observations were reported after analysis of the variables in the study: the increase in seconds (second evaluation) was associated with an increase in the MMP-8 levels (Rho = 0.81, P < .0001) in teeth with pulpitis, high values (P < .0001) of MMP-8 (mean, 0.3607 ng/mL) were observed during the second evaluation in the reversible pulpitis group (from 4 to 5 seconds), and high values of MMP-8 (average, 1.9750 ng/mL) (Rho = 0.80, P < .0001) were observed in the irreversible pulpitis group (from 6 to ≥10 seconds). Here, MMP8 is linked to pulpitis.