RESUMO
The indications and contraindications of adding vasoconstrictors to local anesthesia have long been well recognized, This study was performed to assess the onset, intensity and duration of intraligamentary injection using plain local anesthesia versus those containing vasoconstrictors.Eighty healthy volunteers were participated in the study, 2% mepivacaine with 1:100.00 adrinaline 2% mepivacaine with 1:100.00 noradrinaline.3% mepivascaine and normal saline, as a control, were used. On double blind bases one solution was injected intraligmentory in the lower first molar, using the CITOJECT dental syringe.The onset of anaesthesia in the first three solutions was 10-12 seconds. No significant difference was demonstrated in the intensity of pulpal anaesthesia. Duration of actions was 47.5+7, 03, 61.4+12.27 and 31.5+6.67 minutes respectively. No anaesthesia was abtained in the subjects injected with saline. The addition of vasoconstrictor prolong the duration of anesthesia, nevertheless, within the scope of plain anaesthesia minor oral surgical procedures could be conducted