This randomized clinical trial compared standard single-visit root canal treatment with adjunctive submucosal betamethasone and gentamicin in 100 patients with symptomatic irreversible pulpitis, assessing postoperative pain and inflammatory biomarkers (IL-1β, MMP-9, and RANKL).

This study was designed as a prospective, randomized controlled clinical trial. A total of 100 patients with a VAS pain score ≥7 and SIP in posterior teeth were included. Participants were randomly assigned into two groups: a standard root canal treatment group (n = 40) and an adjunctive treatment group receiving submucosal betamethasone and gentamicin (n = 60). In all cases, conventional single-visit root canal treatment was performed. Gingival crevicular fluid (GCF) samples were collected preoperatively and on postoperative day 3, and VAS scores were recorded at the same time points. Levels of IL-1β, MMP-9, and RANKL in GCF samples were quantified using enzyme-linked immunosorbent assay (ELISA).

Inclusion Criteria:

• Patients diagnosed with symptomatic irreversible pulpitis
• Presence of spontaneous pain or pain persisting after removal of the stimulus
• Teeth indicated for endodontic treatment
• Systemically healthy individuals
• Patients able to read and sign the informed consent form
• Patients able to complete postoperative pain assessment forms
• Patients able to attend the 4-day follow-up visit

Exclusion Criteria:

• Individuals with systemic disease or immunosuppression
• Patients with contraindications to corticosteroid or gentamicin use
• Pregnant or breastfeeding individuals
• Recent use of antibiotics, analgesics, or anti-inflammatory drugs
• Presence of advanced periodontal disease in the affected tooth
• Presence of acute periapical or periodontal abscess
• Teeth with previous endodontic treatment