The aim of this study is premedication efficacy of analgesics on post endodontic pain. Sixty-six healthy adult volunteers including criteria, are participating. The patients will be divided into 3 groups and will be randomly given one of pre medications including 1) 10 mg Ketorolac, 2) 10 mg Ketorolac plus 1000mg Acetaminophen, and 3)Placebo, 45 minutes before applying the injection. All patients will receive standard root canal treatment. Patients will record their post treatment pain using a Heft parker Visual Analog Scale(VAS). Success will be considered as no or mild pain (VAS≤54)with no need to take analgesic. Data will be analysed using Mann-U-Whitney and Kruskal-wallis tests.

The aim of this study is premedication efficacy of analgesics on post endodontic pain. Sixty-six healthy adult volunteers with age ranged 18-65, non smoking or any medicine consumption, non pregnant or break feeding who haven't received any analgesic during 24 hours before the treatment, are participating. The patients will be divided into 3 groups and will be randomly given one of premedications including 1) 10 mg Ketorolac, 2) 10 mg Ketorolac plus 1000mg Acetaminophen, and 3)Placebo, 45 minutes before the treatment. All patients will receive a standard root canal treatment. Patients will record their post treatment pain using a Heft parker Visual Analog Scale(VAS). Success will be considered as no or mild pain (VAS≤54) with no need to take analgesic during 6, 12, 24 and 48 hours intervals following the treatment. Data will be analysed using Mann-U-Whitney and Kruskal-wallis tests.

Inclusion Criteria:

• Patients with age ranged 18-65
• without systemic diseases
• without any medicine consumption
• non smoking
• non pregnant
• non breast feeding
• with asymptomatic irreversible pulpitis ( Visual Analog Scale ≤ 54) in one mandibular molar that needs root canal treatment
• without any medicine consumption or analgesic and sedation who understand and sign the VAS and consent forms.

Exclusion Criteria:

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