Search

Introduction: The inferior alveolar nerve (IAN) block does not always result in successful pulpal anesthesia. Anesthetic success rates might be affected by increased anxiety. Nitrous oxide has been shown to have both anxiolytic and analgesic properties. Therefore, the purpose of this prospective, randomized, double-blind, placebo-controlled study was to determine the effect of nitrous oxide on the anesthetic success of the IAN block in patients experiencing symptomatic irreversible pulpitis., Methods: One hundred emergency patients diagnosed with symptomatic irreversible pulpitis of a mandibular posterior tooth were enrolled in this study. Each patient was randomly assigned to receive an inhalation regimen of nitrous oxide/oxygen mix or room air/oxygen mix (placebo) 5 minutes before the administration of the IAN block. Endodontic access was begun 15 minutes after completion of the IAN block, and all patients had profound lip numbness. Success was defined as no or mild pain (visual analog scale recordings) on access or instrumentation., Results: The success rate for the IAN block was 50% for the nitrous oxide group and 28% for the placebo group. There was a statistically significant difference between the 2 groups (P = .024)., Conclusions: For mandibular teeth diagnosed with symptomatic irreversible pulpitis, administration of 30%-50% nitrous oxide resulted in a statistically significant increase in the success of the IAN block compared with room air/oxygen., (Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

In this study, we performed tests to determine whether tooth pulp stimulation (TPS) increases hippocampal blood flow (HBF), and if so, to investigate whether the increase in HBF is mediated via the activation of adenosine receptors. We measured HBF in urethane-anesthetized rats using laser Doppler flowmetry (LDF) and examined the effect of theophylline, a nonselective adenosine receptor antagonist, on TPS-induced HBF responses. TPS increased HBF, and its response was significantly attenuated by the intraperitoneal administration of theophylline (20 mg/kg). These results suggest that the HBF response induced by TPS may be, at least in part, produced through adenosine receptors.

The purpose of this study was to determine the anesthetic efficacy and heart rate effect of 4% articaine with 1:100,000 epinephrine for supplemental intraosseous injection in mandibular posterior teeth diagnosed with irreversible pulpitis. Thirty-seven emergency patients, diagnosed with irreversible pulpitis of a mandibular posterior tooth, received an inferior alveolar nerve block and had moderate-to-severe pain upon endodontic access. The Stabident system was used to administer 1.8 ml of 4% articaine with 1:100,000 epinephrine. Success of the intraosseous injection was defined as none or mild pain upon endodontic access or initial instrumentation. The results demonstrated that anesthetic success was obtained in 86% (32 of 37) of the patients. Maximum mean heart rate was increased 32 beats/minute during the intraosseous injection. We can conclude that when the inferior alveolar nerve block fails to provide profound pulpal anesthesia, the intraosseous injection of 4% articaine with 1:100,000 epinephrine would be successful 86% of the time in achieving pulpal anesthesia in mandibular posterior teeth of patients presenting with irreversible pulpitis.

Objective: This study aimed to simulate the effects of lasing dentine on pulpal nerve function., Methods: Rat spinal nerve roots were threaded through the prepared pulp canal of a 10 mm long tooth root segment which was mounted in a perspex bath. The protruding ends of the nerve were placed on platinum wire electrodes used to elicit and to record compound nerve action potentials (CAPs). Laser energy (average power = 0.3-3.0 W) was applied to the surface of the root segment using a pulsed Nd:YAG dental laser (dLase 300)., Results: With the laser probe tip placed in static contact with the tooth surface, the nerve CAP was irreversibly abolished within 60 s of lasing at 1.0-3.0 W power. When the laser tip was moved to and fro over the root surface in a scanning mode, similar levels of radiation produced less marked effects. In the latter mode, CAP attenuation increased with increasing power and duration of lasing. After 60 s lasing at 0.3 W, the CAP size was 95% (+/- 5, S.D.) of the prelasing controls value; with 2.0 W the CAP was reduced to 54% (+/- 33). The CAP recovered to 90% of control levels after lasing at powers up to 1.5 W, but reached only 72% of control values after lasing at 2.0 W power., Conclusions: Laser radiation applied to dentine caused a dose-dependent block of action potential conduction in nerve fibres in the underlying pulp chamber.