The addition of a benzodiazepine antagonist to the dental anesthesiologist's armamentarium should provide added safety for conscious sedation using benzodiazepines. A double-blind, placebo-controlled clinical trial of flumazenil, the first available benzodiazepine antagonist, was performed to evaluate its safety and efficacy following conscious sedation induced by diazepam and fentanyl. Flumazenil was found to reverse rapidly much of the central nervous system depression induced by fentanyl and diazepam conscious sedation. Flumazenil appears to be a valuable adjunct for dentists who administer intravenous benzodiazepines for conscious sedation.