This multicenter randomized trial compares the clinical effectiveness of intraligamentary injection versus inferior alveolar nerve block (IANB) in patients with symptomatic irreversible pulpitis in mandibular molars. The goal is to determine which technique provides better pain control during endodontic treatment.

Symptomatic irreversible pulpitis in mandibular molars presents a clinical challenge due to the difficulty in achieving profound anesthesia. This prospective, randomized, controlled clinical trial evaluates two anesthetic techniques-intraligamentary injection (ILA) versus inferior alveolar nerve block (IANB)-to compare their efficacy in eliminating pain during endodontic access. Patients will be enrolled from multiple dental centers following standardized inclusion and exclusion criteria. Pain will be assessed using validated scales. Statistical analysis will be conducted to determine significant differences in anesthetic success between groups.

Inclusion Criteria:

• Adults aged 18 years or older
• Presenting with symptomatic irreversible pulpitis in a mandibular molar
• Vital response to cold testing
• Ability to understand and provide informed consent
• Available for follow-up and data collection

Exclusion Criteria:

• Known allergy to lidocaine or epinephrine
• Pregnancy or breastfeeding
• Use of analgesics or anti-inflammatory drugs in the previous 6 hours
• Non-vital or previously treated teeth
• Significant systemic disease (ASA III or above)
• History of psychiatric or neurological disorders affecting pain perception

This study will not share individual participant data (IPD).

Participants will be unaware of which anesthetic technique is administered. Operators cannot be blinded due to the nature of the procedures.