The inferior alveolar nerve block (IANB) is the most commonly used technique for pulpal anesthesia in the mandible, especially the mandibular molars. Due to the dense cortical bone of the mandible, buccal infiltration techniques have been known to be less successful.
However, the IANB has challenges of its own. Passing through layers of soft tissue and muscle and depositing the anesthetic in adjacent to the mandibular foramen can be very difficult. Anatomical variation among patients, including the course of the nerve, location of the mandibular foramen, accessory nerves also innervating the area can all make consistancy with this technique challenging.
If the block is unsuccessful, then the practitioner has typically repeats the block or trys another technique. The most common alternative techniques are: closed mouth block (Vazirani/Akinosi), Gow-Gates Block, intraligamentary injection, intrapulpal injection, or intraosseous injection.
Manibular buccal infiltration has traditionally not been considered as an option due to the inability for the anesthetic to diffuse through the thick cortical plate. Kanaa et al. reported that a mandibular buccal infiltration is more effective with 4% articaine with 1:100,000 epinephrine than with the traditional 2% lidocaine.
A recent study by Il-Young Jung et. al. compared the efficacy of IANB with that of buccal infiltrations in mandibular first molars.
Using 4% articaine subjects were given IANB and BI on separate appointments. Pulpal anesthesia was determined using an electric pulp tester. 54% of BI were successful and 43% of IANB were successful. (the difference was not significant p=0.34) The onset of pulpal anesthesia was significantly faster with BI (p=0.03). This study concluded that BI with 4% articaine for mandibular first molars can be a useful alternative to IANB due to it’s faster onset and similar success rate.
Having difficulty with anesthetizing mandibular molars? Try using some 4% articaine in a buccal infiltration.