Abstract
The positive aspirations obtained with a self-aspirating syringe (Astra, Sweden) were compared with those obtained when aspiration was performed manually (Uniject® syringe, Hoechst, West Germany). The subjects were 1186 army recruits, to whom 2348 injections of local anesthetic were given in connection with dental treatment.
When aspiration was performed manually, the results were positive in 4.7% of the cases;