Matrix metalloproteinase 8 production of cariously-exposed irreversible pulpitis.

BACKGROUND/PURPOSE: Matrix metalloproteinase 8 (MMP-8) is a major enzyme released by neutrophils and may serve as a potential biomarker for pulpal inflammation. This study aimed to compare MMP-8 levels in normal pulp and cariously-exposed pulp diagnosed with irreversible pulpitis, including both asymptomatic irreversible pulpitis (AIP) and symptomatic irreversible pulpitis (SIP) and to assess the association between clinical factors and MMP-8 concentrations in the pulpitis group. MATERIALS AND METHODS: Pulpal blood samples were collected following caries removal in pulpitis cases or intentional pulp exposure in the normal pulp group. Both active and total forms of MMP-8 were measured. Clinical factors that might affect the concentrations of MMP-8 in the pulpitis group (AIP and SIP), were included to determine theircorrelations. RESULTS: Fifteen teeth diagnosed with irreversible pulpitis (AIP and SIP) and five sound premolars (normal pulp) were included. Higher concentrations of MMP-8 were observed in both AIP and SIP groups (AIP: active = 18.40 ± 3.04 ng/mL, total = 36.79 ± 7.88 ng/mL; SIP: active = 16.06 ± 3.10 ng/mL, total = 32.02 ± 6.12 ng/mL) compared to normal pulps (active = 4.63 ± 0.96 ng/mL, total = 7.17 ± 1.41 ng/mL). No significant difference was found between AIP and SIP. The presence of radiographic periapical pathology was significantly associated with increased MMP-8 concentrations in the pulpitis group. CONCLUSION: Irreversible pulpitis exhibited elevated MMP-8 levels regardless of pulpal pain symptoms. MMP-8 concentrations were significantly higher in cases with periapical pathology, supporting its potential role as a bioactive marker for pulpal inflammation.