Syringe esp. for injecting anaesthetic into the lower jaw - includes pref. triangular needle guide and scale showing depth of needle penetration

摘要

Syringe, more partic. for penetrating a hard wall as when injecting an anaesthetic into the lower jaw, has a triangular mouthpiece guide through which the needle can slide. The body of the syringe has a scale which indicates the length of the needle projecting through the tip of the guide. In use, the operator applies the tip of the mouthpiece to the interdental space of the gum. Force is applied to the syringe; and the needle penetrates the gum while the mouthpiece remains resting on the gum and its other end slides on the syringe body. Penetration is stopped when the scale shows that the desired depth has been attained. Finer needles, allowing for easier penetration, can be used with less risk of bending and less force is needed by the operator.