Inclusion Criteria:  Patients in good health (American Society of Anesthesiologists Class I or II). Patients having symptomatic irreversible pulpitis in one of their mandibular molars. Age range between 18 to 50 years. Patients who can understand Numerical Rating Scale (NRS). Positive patient acceptance and the ability to sign an informed consent.  Exclusion Criteria:  Pregnant females. Patients allergic to articaine, mepivacaine and/or any used medication or material. Patients having active sites of pathosis in the area of injection. Patients having active pain in more than one molar. Patients who had taken analgesics in the 12 hours preceding treatment.