The aim of this study is to investigate the levels Neurokinin A and of Matrix Mtalloproteinase (MMP-9) in gingival crevicular fluid samples (GCF) as potential biomarkers for the diagnosis of symptomatic irreversible pulpitis with symptomatic apical periodontitis and to correlate the level of these diagnostic biomarkers ( Nerokinin A and MMP-9) with the pre-operative pain severity using the Numerical Rating Scale (NRS).

This study will utilize a comparative cross-sectional design to assess the levels of Neurokinin A (NKA) and Matrix metalloproteinase-9 (MMP-9) in gingival crevicular fluid (GCF) samples from symptomatic and healthy contralateral teeth with normal pulp.

The study design is Comparative Cross sectional study. The study will be conducted at the Dental hospital of Cairo University with access to patients undergoing treatment for teeth with pulpitis and apical periodontitis.

Inclusion Criteria:

• Adults (aged 18-60) diagnosed with symptomatic irreversible pulpitis with symptomatic apical periodontitis and have healthy contralateral teeth with normal pulp.
• The involved teeth should have healthy periodontal conditions (Normal periodontal pocket depth, No bleeding on Probing and No mobility).
• Patients who have not undergone any previous dental treatments in the involved teeth.
• Signed informed consent.

Exclusion Criteria:

• Patients with systemic diseases affecting the immune response (e.g., autoimmune diseases, uncontrolled diabetes).
• Patients taking medications that can affect the inflammatory markers (e.g., Steroids and Tetracyclins).
• Smokers.
• Individuals with periodontal disease unrelated to apical periodontitis.
• Presence of marginal bone loss.
• Pregnant women.

Adults (aged 18-60) diagnosed with symptomatic irreversible pulpitis with symptomatic apical periodontitis and have their healthy contralateral teeth with normal pulp with clinically healthy periodontium and not undergone any previous treatments in the involved teeth.