The purpose of this study was to investigate the manufacturer's claims regarding a novel needleless intraligamentary local anesthesia injection device (Numbee, BioDent) to provide effective single tooth anesthesia. Investigators compared the Numbee with a traditional inferior alveolar nerve block (IANB) during a restorative procedure on mandibular teeth. A randomized, split-mouth design was conducted with 15 adult subjects receiving an IANB on one side and a Numbee injection on the same tooth type on the contralateral side. Subjects recorded injection pain using the Visual Analog Scale (VAS) and their preferred injection technique. Anesthesia was considered profound with 2 consecutive electric pulp tester readings of 80. If subjects became symptomatic during the restorative procedure, rescue anesthesia was administered. The difference in VAS scores for injection pain between the Numbee and the IANB was not significant (p = .078). For the IANB, the incidence of profound anesthesia was 46%, and required rescue anesthesia was 20%. For the Numbee, the incidence of profound anesthesia was 0%, and required rescue anesthesia was 60%. Subject preference was evenly split (50/50%) between the 2 techniques. The IANB outperformed the Numbee device for achieving profound anesthesia and requiring less rescue anesthesia.