Mandibular Infiltration Injections  

What it numbs:

Infiltration injections are anesthetizing the long terminal branches of the nerves.

The mandibular infiltration injection anesthetizes the soft tissue in the area if the injection site.


The recommended needle gauge and length are a 25 or 27 short.  


Patient position is supine or semi supine depending on location.

Operator position is going to depend on the areas being anesthetized.


The landmarks are the mucobuccal fold parallel to the root and apex of the tooth close to the bone.  

Target area:

The target area and injection site is located at the mucobuccal fold parallel to the long axis of the tooth to be anesthetized.  

The bevel of the needle should be toward the bone and inserted at a depth of 2-3 mm for the mandibular.

There is no pressure anesthetic or osseous contact needed with infiltration injections. aspiration potential is less than one percent.  

Aspirate, if negative slowly inject 1/3 of the carpule over 20 seconds.

If isolated areas of the lingual tissue require anesthetic, local infiltration can be accomplished by inserting the short needle though the interdental papilla on both the mesial and distal of the tooth being treated. This will provide adequate anesthetic for scaling, root planning and curettage with out the patient having to experience anesthesia of the tongue.


Document in patient record, what injection you gave, who gave it, what kind of anesthetic, how much anesthetic, negative aspiration, no complications, ect.


For more information and references:

Handbook of Local Anesthesia by Malamed