The effects of a 2-stage injection technique on inferior alveolar nerve block injection pain.

The purpose of this prospective, randomized, single-blinded, crossover study was to compare the pain of a traditional 1-stage inferior alveolar nerve (IAN) block injection to a 2-stage IAN block technique. Using a crossover design, 51 subjects randomly received, in a single-blinded manner, either the traditional IAN block or the 2-stage IAN block in 2 appointments spaced at least 1 week apart. For the 2-stage injection, the needle was inserted submucosally and 0.4 mL of 2% lidocaine with epinephrine was slowly given over 1 minute. After 5 minutes, the needle was reinserted and advanced to the target site (needle placement), and 1.8 mL of 2% lidocaine with epinephrine was deposited. For the traditional IAN block, following needle penetration, the needle was advanced while depositing 0.4 mL of 2% lidocaine with epinephrine (needle placement) and then 1.8 mL of 2% lidocaine with epinephrine was deposited at the target site. A Heft-Parker visual analogue scale was used to measure the pain of needle insertion, needle placement, and anesthetic solution deposition. There were no significant differences, as analyzed by Wilcoxon matched-pairs signed-ranks test, between needle insertion and solution deposition for the 2 techniques in men or women. However, there was significantly less pain with the 2-stage injection for needle placement in women. In conclusion, the 2-stage injection significantly reduced the pain of needle placement for women when compared to the traditional IAN technique.