To assess the anesthetic success of inferior alveolar nerve block (IANB), intraoperative pain intensity and need for supplemental anesthesia on administration of 1.8ml or 3.6ml 2% mepivacaine IANB, or 1.8ml 2% mepivacaine IANB plus 1.8ml 4% articaine buccal infiltration (BI) in mandibular molars with symptomatic irreversible pulpitis.

Patients with moderate-to-severe preoperative pain related to mandibular molars with symptomatic irreversible pulpitis will be included. Patients receive 1.8 ml, 3.6 ml 2% mepivacaine IANB, or 1.8ml 2% mepivacaine IANB plus 1.8ml 4% articaine BI. Anesthetic success of inferior alveolar nerve block, intraoperative pain intensity and need for supplemental anesthesia will be assessed during treatment.

Inclusion Criteria:

1. Patients in good health (ASA Class I, II).
2. Age between 18-60 years old.
3. Males or females.
4. Mandibular molar teeth diagnosed with symptomatic irreversible pulpitis.
5. Patients who can understand NRS scale and sign the informed consent.

Exclusion Criteria:

1. Patients who had used any type of analgesic medication during the preceding 8 hours before the treatment.
2. Pregnant or nursing females.
3. Patients with a contraindication for the use of mepivacaine, articaine or any used drug or material.