摘要 |
An aspirating hypodermic syringe and method for injecting dental anesthetic in which anesthetic flow through the needle is established independently of the fingers of the operator and in which different rates of flow are provided, including positive flow while the needle is entering the tissue. Effective aspiration in syringes which use expendable anesthetic vials is assured by means of a yieldable resistance member in the syringe which holds the vial with sufficient force to enable the syringe plunger to lock positively onto the piston of the vial.
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