Anaesthetic efficacy of 4% articaine compared with 2% mepivacaine: a randomized, double-blind, crossover clinical trial.

The aim of this study was to evaluate the clinical efficacy of 4% articaine (Ar4) compared to 2% mepivacaine (Me2), both in combination with 1:100,000 epinephrine, in a unique soft tissue model. This was a randomized, double-blind, crossover clinical trial. The anaesthetic was applied to the lower lip using a computerized local delivery system. The following were evaluated: blood flow, thermal sensation, pressure and proprioception, extent of anaesthesia, gradual elimination, and the final duration of the effect of the anaesthesia. Seventy-two volunteers completed all parts of the study. Significant differences, which indicated better effectiveness of Me2 compared to Ar4, were observed in the following tests: reduction in blood flow (larger in the Me2 group); anaesthetized area at 30min (larger in the Me2 group); pressure tests; temperature tests after 20min; fine and discriminatory proprioception tests after 20min. The volunteers' perception of anaesthesia at 30, 40, 50, and 60min was superior for Me2 at all recorded time points. The duration of anaesthesia was also superior for Me2. The overall performance of Me2 was superior to Ar4, implying that Me2 provides a more effective anaesthesia in terms of depth, extent, and duration.