Pulpal and periapical inflammation and infection can cause tissue pH in the affected region to be lowered which results in less penetration of anesthetic solution in the nerve membrane and hence delays the onset of anesthesia. So, the purpose of this study was to compare the pulpal anesthetic efficacy of lidocaine, articaine, mepivacaine for inferior alveolar nerve block (IANB) in patients with irreversible pulpitis (IP). One hundred and twenty adult patients with IP concerning mandibular molars randomly received IANB with either of the three solutions: 2% lidocaine with epinephrine; 4% articaine with epinephrine; 3% plain mepivacaine. Pain during the endodontic treatment was assessed using a visual analog scale (Heft-Parker VAS). Endodontic treatment was initiated. Success was defined as no or mild pain (pain score≤54mm on Hp VAS) during access preparation and root canal instrumentation. The anesthetic success rates were analyzed with the chi-square test.

Inclusion Criteria:

• active pain in a mandibular molar
• prolonged response to cold testing with an ice stick and an electric pulp tester
• absence of any periapical radiolucency on radiographs, except for a widened periodontal ligament
• vital coronal pulp on access opening and ability to understand the use of pain scales

Exclusion Criteria:

• known allergy, sensitivity, or contraindications to any opioid or nonopioid analgesic including aspirin or NSAIDs
• history of active peptic ulcer within the preceding 12 months
• history of bleeding problems or anticoagulant use within the last month
• patients who were pregnant or breast-feeding
• a history of known or suspected drug abuse
• patients who had taken NSAIDs within 12 h before administration of the study drugs