Difference in the Effects of Lidocaine With Epinephrine and Prilocaine With Felypressin on the Autonomic Nervous System During Extraction of the Impacted Mandibular Third Molar: A Randomized Controlled Trial.

PURPOSE: Complications during local anesthesia include increased blood pressure and vasovagal reflex, which are caused by changes in the autonomic nervous system. The commonly used local anesthetic preparations are lidocaine to which the vasoconstrictor epinephrine is added (lidocaine-epinephrine) and prilocaine to which the vasoconstrictor felypressin is added (prilocaine-felypressin); however, their effects during dental treatment are unclear. We examined the effects of these 2 different local anesthetic preparations on the autonomic nervous system and circulation during extraction of the impacted mandibular third molar.

MATERIALS AND METHODS: In this randomized controlled trial, 40 female patients scheduled for extraction of an impacted mandibular third molar were randomized to the lidocaine-epinephrine group or prilocaine-felypressin group. Heart rate variability, heart rate, and systolic blood pressure were recorded during the experiment. Descriptive and bivariate statistics were computed, and the P value was set at .05.

RESULTS: The low frequency-high frequency ratio was significantly increased in the prilocaine-felypressin group during extraction compared with that in the lidocaine-epinephrine group (P < .05). In the lidocaine-epinephrine group, a significant decrease in the high-frequency component was observed during bone removal and extraction compared with that at rest (P < .05). In both groups, a significant increase in systolic blood pressure was observed during local anesthesia, incision and reflection of the flap, bone removal, separation of the tooth crown, extraction, and suturing compared with that at rest (P < .01).

CONCLUSIONS: This study is the first to investigate the differences in the influence of 2 different local anesthetic preparations on the autonomic nervous system during extraction of the mandibular third molar. Changes in circulatory dynamics during tooth extraction with the 2 different local anesthetic preparations were the result of a decrease in parasympathetic nervous activity with lidocaine-epinephrine and an increase in sympathetic nervous activity with prilocaine-felypressin.