ributed questionnares.[@ref15],[@ref17],[@ref18] Our data indicated that approximately 14% of the students and interns (overall) observed IANB failure very often or often, which is consistent with some prior studies.[@ref1],[@ref3],[@ref6] In general, similar responses were provided by males and females, with the exception of the complication frequency data, which showed that males have more complications than females. Our finding that almost half (47%) of the participants in our study repeated the standard IANB injection to achieve profound anesthesia is consistent with the work of Malamed,[@ref1] who recommend to repeat the conventional IANB to overcome IANB failure, and Johnson et al,[@ref15] who found that 70% of their respondents repeated a standard IANB injection. Only 20.5% of our surveyed sample (37.5% of third-year and 33.3% of fourth-year students) indicated that they were able to overcome IANB failures by repeating the conventional IANB until it worked. The reliance on repeat injection may be due to the fact that they were not able to perform alternative techniques. The most common response to IANB failure by third and fourth year students was to ask their supervisors for help; no similar study could be found with which to compare this finding. The portion of our interns who never tried any alternative techniques (42.8%) was modestly greater than the portion reported by Johnson et al[@ref15] (30%).

Small minorities of respondents in this study reported using the Gow-Gates technique (10.3%) or the Vazirani-Akinosi technique (2.9%). These findings are reasonably similar to those of Johnson et al's study.[@ref15] Harvard School of Dental Medicine study[@ref15] with a one-page survey in which only 14.9% of participants were using the Gow-Gates technique and only 7.5% were reported using the Vazirani-Akinosi technique. However, the most common subsequent course of action in cases of IANB failure differed between our study (infiltration, 55.9%) and Johnson et al's study[@ref15] (repeat standard IANB, 70.21%