2TheApex: Two inferior alveolar nerve blocks (IANB) are more effective than one in both symptomatic and asymptomatic patients.
A recent article published in the Journal of Endodontics showed that administering 2 carpules of local anesthetic was significantly more effective at achieving profound lip anesthesia. 3169 people participated in the study with failure rates of 7.7% with one carpule, and 2.3% with two carpules of 2% Lido with 1:100,000 epi. Although this may seem like common sense, it is the first article to show that increasing volume will increase IANB success rates. This study only examined anesthetic success in terms of lip numbness, not as a pain free procedure. As we all know, pain can still be present during the procedure even with profound lip numbness. However, adequate anesthesia will almost never be achieved without first achieving lip numbness as a sign of a successful IANB first.