Introduction: The success rate of inferior alveolar nerve block (IANB) decreases in patients with irreversible pulpitis. It was hypothesized that supplemental infiltration of lidocaine and articaine may improve the success rates.
Methods: Eighty-four adult volunteers, actively experiencing pain, participated in this prospective, randomized, double-blinded study. All patients received standard IANB of 2% lidocaine with 1:200,000 epinephrine. Twenty-four patients did not receive supplemental infiltrations (control). Thirty patients received supplemental buccal and lingual infiltrations of 2% articaine with 1:200,000 epinephrine, and 30 patients received buccal and lingual infiltrations of 2% lidocaine with 1:200,000 epinephrine at 2 minutes after the IANB. Endodontic access preparation was initiated after 15 minutes of initial IANB. Pain during treatment was recorded by using a Heft Parker visual analog scale. Success was recorded as "none" or "mild" pain.
Results: Statistical analysis using nonparametric McNemer tests showed that supplemental buccal and lingual infiltration of 2% lidocaine with 1:200,000 epinephrine or 4% articaine with 1:200,000 epinephrine improved the success rate from 33% to 47% and 67%, respectively. Also the success rate with 4% articaine with 1:200,000 epinephrine was significantly more than 2% lidocaine with 1:200,000 epinephrine (p < 0.05).
Conclusions: Although supplemental buccal and lingual infiltrations of 4% articaine or 2% lidocaine increased the success rate of the inferior alveolar nerve block in patients with irreversible pulpitis, none of the techniques provided acceptable success rates.