Comparison of Three Techniques of Mandibular Local Anesthesia in Terms of Blood Aspiration Probability

One of the most important principles in dental local anesthesia is aspiration before injection which can prevent a lot of emergencies in dentistry. The purpose of this study was to compare three techniques of mandibular local anesthesia in terns of blood aspiration probability. A full trained oral and maxillofacial surgeon performed 424 injections on 236 patients (88 males and 148 females, average age 26) using one standard aspirable syringe system and one type of needle with 34 mm length and 27 gauge. Patients who had systemic diseases were omitted; for the other patients one or more of three techniques of local anesthesia was performed which consisted of direct or indirect techniques inferior alveolar nerve block and mandibular nerve block by Gow-Gates technique. Frequency of injections in each group included: direct technique 180 injections, indirect technique 123 injections and Gow-Gates technique 121 injections. Aspiration was performed at the start of each type of injection. In each block the age and sex of patients were recorded, along with anesthetic technique and blood aspiration (either positive or negative). The X2 test was used to analyze the variables and data. In this study we found that: the positive aspiration rate was 8.3, 7.3 and 7.4 % by direct, indirect and Gow-Gates techniques respectively. No significant differences were observed among the anesthetic techniques performed. The findings of this study demonstrated no significant differences among all the techniques of nerve blocks and all these techniques are equally effective in performing this procedure.