Changes in Pulpal Microcirculation Following Local Anaesthesia

Objectives: To investigate the effect of local infiltration anesthesia with 3 different anesthetic solutions on pulpal blood flow in human anterior teeth. Methods: Eighteen intact upper incisors in 9 healthy volunteers were anaesthetized with 2 ml of one of the following anesthetic solutions: a) mepivacaine 3% ( Mepivastesin ) , b) prilocaine 3% with felypressin 0.03 IU/ml (Citanest), and c) articaine 4% with adrenaline 1:100000 ( Ubistesin F).Pulpal blood flow was monitored by laser Doppler flowmetry. The depth and duration of local anesthesia was also studied using a monopolar electric pulp tester.Each one of the anaesthetic solutions was investigated in all teeth Results: Infiltration of Mepivastesin produced negligible changes in pulpal blood flow. Complete anesthesia was observed 10 min after the injection but it was short lasted (15+/- 5 min.). Infiltration of Citanest caused a slight decrease in pulpal blood flow (6+/-1%) which lasted for about 5 min. Complete anesthesia was observed 5 min after the injection with a duration of 40+/-5 min. Infiltration of Ubistesin F caused a severe reduction of pulpal blood flow (80+/- 5 %) which started 5 min. after the injection and lasted for 45 min. Then it was gradually increased and reached normal values 80 min after the injection. Complete anesthesia commenced 5 min after the injection and lasted 80+/- 10 min. Conclusions: Local infiltration anaesthesia utiling solution with adrenaline severely reduced pulpal blood flow for prolonged time periods. In contrast, anesthetic solutions without vasoconstrictor or with felypressin as vasoconstrictor did not adversely affect pulpal blood flow and, therefore, are preferable for clinical use in conservative tooth interventions.