ARE INTRALIGAMENTARY INJECTIONS INTRAVASCULAR

A pressure type syringe was used to give intraligamentary injections ( IL) to upper teeth of two formulations commonly used in general practi ce, lignocaine and prilocaine. Assay of plasma levels of drug was carr ied out by high performance liquid chromatography. Results of assays a fter intraligamentary injections were then compared with results of as says after intravenous injections of plain drug in the same subjects. Both formulations of local anaesthetic were found as peak levels in th e circulation, presumably after intraosseous spread, by 2 minutes foll owing the intraligamentary injections. For lignocaine the peak amount was nearly 7% of the intravenous dose and for prilocaine the peak amou nt was 25% of the intravenous dose, at 2 minutes after injection. It w as concluded that IL injections for healthy adults were unlikely to ca use systemic unwanted effects when given in small doses.