Reversal of Soft-tissue Anesthesia in Asymptomatic Endodontic Patients: A Preliminary, Prospective, Randomized, Single-blind Study

IntroductionPhentolamine has been reported to be an effective local anesthetic reversal agent for soft tissue but has not been studied in endodontics. The purpose of this preliminary, prospective, randomized, single-blind study was to evaluate the reversal of soft-tissue anesthesia using phentolamine in asymptomatic endodontic patients.MethodsEighty-five adult subjects having a maxillary or mandibular asymptomatic tooth requiring endodontic therapy received either phentolamine or sham treatment(s) at the end of the endodontic treatment appointment. Soft-tissue anesthesia was monitored by subjects every 15 minutes for 5 hours. Subjects reported postoperative injection site pain and tooth pain using a Heft-Parker visual analog score every 30 minutes for the first 2 postoperative hours and every hour for 3 hours.ResultsThere was a statistically significant difference in time to return-to-normal sensation for the maxillary lip/cheek and mandibular lip. Subjects who received phentolamine experienced an 88-minute decrease in time to return-to-normal maxillary lip/cheek sensation and a 47-minute decrease in time to return-to-normal mandibular lip sensation. The administration of phentolamine was not significantly more painful than administration of a sham treatment, and patients who received phentolamine did not experience significantly more postoperative pain at the injection site. Postoperative complications were minimal, and no clinically significant adverse reactions to the phentolamine were reported.ConclusionsPhentolamine would be beneficial for asymptomatic endodontic patients who would like to experience a faster return-to-normal soft-tissue function and sensation after the administration of local anesthesia.