Effect of needle design on pain from dental local anesthetic injections

The purpose of this randomized, double-blind clinical study was to evaluate the effectiveness of a larger-bore compared with a standard-bore dental local anesthetic needle of the same gauge in reducing pain during inferior alveolar (IA) and long buccal (LB) nerve block injections. Twenty active duty military or Department of Defense beneficiaries undergoing dental treatment were anesthetized using a split-mouth design with 4 anesthetic dental injections. Both sides of the mouth received IA nerve block and LB nerve injections, one using the 27-gauge large-bore Septoject XL needle and other using a 27-gauge standard-bore Septoject needle. Patients rated the pain experienced with each method using a visual analogue scale (VAS). The IA injection mean VAS score and standard deviation were 38.9 ± 22.7 mm and 37.1 ± 22.4 mm, respectively, for the larger and standard-bore needles. The LB injection mean VAS score and standard deviation were 33.5 ± 22.8 mm and 35.1 ± 19.6 mm, respectively, for the larger and standard-bore needles. The data were analyzed with a paired t test (α = .05). No significant difference was found between the IA (P = .70) or LB injections (P = .73). The use of a larger-bore 27-gauge needle did not reduce pain on injection compared with the standard-bore 27-gauge needle.