Positive Aspiration And Achievement Of Inferior Alveolar Nerve Block

Inferior alveolar nerve block (IANB) is used in routine dental practice. One factor affecting the success is aspiration which prevents intravascular injection and reduces systemic complication. Reported rate of positive aspiration ranged from 10-15%, whereas the success rate ranged from 80-85%. Objectives: To investigate the positive aspiration rate and effect of positive aspiration on an achievement of IANB. Methods: Thirty-two fourth-year dental students were included in this study. IANB was performed using direct technique. Local anesthetic agent was lidocaine 2% with epinephrine 1:100,000. Aspiration result, achievement, onset and duration of anesthesia were recorded. Relationship between aspiration result and achievement of anesthesia was analyzed using Fisher's exact test, whereas the means of onset and duration between the positive and negative aspiration groups were compared using unpaired t-test. Results: Positive aspirations were found in 5 cases (15.6%), whereas the success rate was 90.7%. The mean onset and duration of positive-aspiration group were 4.25+/-0.48 minutes and 197.3+/-14.3 minutes respectively, whereas those of negative-aspiration group were 3.24+/-0.47 minutes and 215.1+/-9.5 minutes respectively. There was no relationship between positive aspiration and achievement of IANB (p=0.4103), whereas the means of onset and duration of positive-aspiration group were not different from those of negative-aspiration group (p=0.4095 and 0.4149 respectively). Conclusions: The rates of IANB positive aspiration and success were closed to the previous reports. Positive aspiration had no effect on the achievement of IANB, as well as onset and duration of anesthesia.