Efficacy Of Pulpal Anesthesia Using A Needle-less Syringe

Objectives: Dentistry utilizes many resources with the intention of reducing patient anxiety during local anesthetic administration. The purpose of this study was to compare the use of a new needle-less intraligamentary injection device, the NumBee^TM (GoldenDent^TM), to the traditional Inferior Alveolar Nerve (IAN) block. This study evaluated pain upon injection and potential to achieve pulpal anesthesia during a caries restorative procedure on mandibular teeth.
Methods: A randomized, split-mouth design of 15 adult subjects receiving two anesthetic dental injections using 2% lidocaine with 1:100,000 epinephrine was conducted. Subjects received an IAN block on one side of the mandibular arch and a NumBee^TM injection on the same tooth type (molar, premolar) on the contralateral side. Subjects recorded injection pain using the Visual Analog Scale (VAS) and the injection technique they generally preferred. An electric pulp tester (EPT) was used to assess pulpal anesthesia at the 5-, 15-, 30-, 45- and 60-minute intervals. Anesthesia was considered profound with two consecutive EPT readings of 80 (EPT maximum output). If subjects became symptomatic during the restorative procedure, rescue anesthesia was administered.
Results: A Wilcoxon Signed Rank Test revealed no statistically significant difference (P=0.078) in median VAS scores with pain upon injection between the NumBee^TM (median 33.0 mm, IQR 39.9 mm) and IAN block (median 44.0 mm, IQR 34.6 mm). Patient preference was evenly split (50%) between the two techniques. The IAN block required rescue anesthesia during 20% of procedures and the anesthesia was determined to be profound during 46% of procedures. The NumBee^TM injection required rescue anesthesia during 60% of procedures and the anesthesia was never determined to be profound (0%).
Conclusions: No statistically significant difference in pain upon injection or patient preference was found between NumBee^TM and IAN block. The IAN block outperformed the NumBee^TM in achieving profound anesthesia and requiring less rescue anesthesia.