Study activities never commenced.

Articaine/epinephrine and lidocaine/epinephrine are the most common routine local anesthetic agents currently used in dentistry. However, their anesthetic efficacy and pain control in patients with symptomatic irreversible pulpitis via inferior alveolar nerve block is very low. The aim of this study is to investigate the efficacy of clonidine versus articaine/epinpephrine as a local anesthetic agent for a buccal infiltration after IANB administration with lidocaine for (1) successful IANB, (2) hemodynamic stability, and (3) reducing dental anxiety for endodontic treatment in mandibular molars diagnosed with symptomatic irreversible pulpitis.

Articaine/epinephrine and lidocaine/epinephrine are the most common routine local anesthetic agents currently used in dentistry. However, their anesthetic efficacy and pain control in patients with symptomatic irreversible pulpitis via inferior alveolar nerve block is very low. The aim of this study is to investigate the efficacy of clonidine versus articaine/epinpephrine as a local anesthetic agent for a buccal infiltration after IANB administration with lidocaine for (1) successful IANB, (2) hemodynamic stability, and (3) reducing dental anxiety for endodontic treatment in mandibular molars diagnosed with symptomatic irreversible pulpitis. 100 patients with first or second mandibular molars diagnosed with symptomatic irreversible pulpitis will be enrolled. Patients will randomly receive either 1.7mL of clonidine (1:100,000) or 1.7mL of 4% articaine with epinephrine (1:100,000) using buccal infiltration technique after administration of 1.7mL of 2% lidocaine with epinephrine (1:100,000) using an IANB technique. 15 minutes after injection, lip numbness will be checked. Those who reported lip numbness will be checked for pulpal anesthesia. Those who achieve profound pulpal anesthesia will be included in the study. Patient's pain score will be recorded using a Heft-Parker visual analog scale before, during and after endodontic treatment. Success in IANB is defined as no or mild pain upon endodontic access cavity preparation and initial canal instrumentation. The hemodynamic parameters and pain management will be measured before and after root canal treatment with specific intervals. Patient's dental anxiety level will be measured by VAS-Anxiety preoperatively, before IANB administration, before endodontic treatment and after the treatment.

Inclusion Criteria:

• Be at least 18 years of age;
• Provide written informed consent prior to participation and be given a signed copy of the informed consent form;
• Must be in general good health as determined by the Investigator based on a review of the health history/update for participation in the trial (American Society of Anesthesiologists classification 1); and
• Have a diagnosis of symptomatic irreversible pulpitis and symptomatic apical periodontitis for their mandibular first or second molar.

Exclusion Criteria:

• Active signs of oral infections or inflammation;
• History of addiction or use of beta blockers;
• Use of medications that could affect anesthetic assessment (opioids at least one week before treatments);
• Allergies or contraindications to the use of clonidine, epinephrine or ibuprofen;
• Pregnant or nursing per subject report;
• No response to cold testing;
• Any diseases or condition that might interfere with the safe participation in the study; and
• Inability to undergo study procedures