RESUMO
This study aimed to investigate the hypothesis that vasopressin extends the anesthetic response time of lidocaine and does not affect the circulatory dynamics. Rats were sedated with isoflurane; subsequently, breathing was maintained through mechanical ventilation. We infiltrated the first molar area of the upper left jaw with saline (NS, test solution), 2% lidocaine (L), 0.025 IU vasopressin-supplemented 2% lidocaine, 0.05 IU vasopressin-supplemented 2% lidocaine, 0.1 IU vasopressin-supplemented 2% lidocaine, and 0.2 IU vasopressin-supplemented 2% lidocaine (VL4). Further, anesthetic response times were measured up to 30 min using electric pulp testing methods (n = 4). The anesthetic response times of NS, L, and VL4 were measured up to 45 min with the aforementioned results as reference values (n = 7). The circulatory dynamics of NS, L, VL4, and 0.2 IU vasopressin (V) were measured up to 45 min using a non-invasive blood pressure measuring device. VL4 extended the anesthetic response times of lidocaine compared to L (p < 0.05). Further, V and VL4 significantly increased the systolic and diastolic blood pressure and significantly decreased the pulse rate (p < 0.05). VL4 is not a suitable addition to the local anesthetic solution used in dentistry. Further study is needed to determine vasopressin concentration that extends the anesthetic effect without affecting the circulatory dynamics.