Anesthetic Efficacy of an Alternative Inferior Alveolar Nerve Block Technique Using an Extra-Short Needle: A Double-Blind Randomized Non-Inferiority Trial.

PURPOSE: Inferior alveolar nerve block (IANB) is a frequently used anesthetic technique for restorative and surgical procedures in the mandible and its success rate usually ranges from 80 to 85%. Thus, this study aimed to compare the anesthetic efficacy of an alternative technique named superficial nerve block (SNB)-which consists of a modified approach using an extra-short needle inserted 10 mm deep and on a higher injection site to the conventional technique (CT) for IANB in healthy individuals.

METHODS

About 20 participants received both SNB and CT with 1.8 mL of 2% lidocaine and 1:100,000 epinephrine. Thermal tests were performed 6 times, every 2 min, on the inferior canine and first molar to determine the success rate and anesthesia onset. Assessments were repeated at 20, 40, and 60 min to determine anesthesia duration. Sensitivity of lips and tongue was tested by clamp pressure. Pain perception during injection was assessed by a 100 mm visual analog scale (VAS).

RESULTS

The success rate in accordance with anatomical location was molars (SNB = 90%; CT = 85%), canines (SNB = 25%; CT = 70%), lips (SNB = 45%; CT = 95%), and tongue (SNB = 85%; CT = 95%). Significant differences were found for canines (P = .012) and lips (P < .002). Moreover, median anesthesia onset was: molars (SNB = 6 min; CT = 4 min), canines (SNB = 6 min; CT = 6 min), lips (SNB = 10 min; CT = 6 min), and tongue (SNB = 8 min; CT = 4 min), whereas median duration was molars (SNB = 60 min; CT = 60 min), canines (SNB = 20 min; CT = 60 min), lips (SNB = 60 min; CT = 60 min), and tongue (SNB = 60 min; CT = 60 min). A significant difference was found for anesthesia onset on molars (P = .024) and lips (P = .009). Pain scores on VAS were SNB (median = 8.5 mm) and CT (median = 10.0 mm) (P = .398).

CONCLUSIONS

In healthy individuals, the anesthetic effects of SNB were noninferior to CT in molars and tongue, although efficacy was considerably inferior in anterior teeth and lips.