by Dr Patrick Colgan, Fremantle, WA

Ligmaject is a gun-shaped syringe that injects small amounts of anaesthetic under high pressure. It has a very short needle that is introduced between the tooth and the bone. Once it has slipped down alongside the tooth, you deliver a drop or two of anaesthetic under pressure, and the liquid runs down the surface of the root to where the nerve enters tooth. Its application is really only applicable to the mandibular posterior teeth.

What’s good about it
The anaesthesia is localised to an individual tooth and there is no carry-over numbness to the tongue or lips. Ligmaject has been around for a long time but did not seem terribly popular with dentists. However, with the advent of Articane Hydrochloride, it works a treat. It’s quick, convenient for the patient and is a very profound anaesthesia.
Even though Articane is great anaesthetic, it’s not recommended for use in the lower jaw as a conventional block injection because there’s some risk of leaving the nerve with long-term numbness. By using it with the Ligmaject system, it works really well—particularly in emergency situations when you need to get the patient numbed quickly and begin repair work.
I always show patients the gun and explain the needle doesn’t pass through tissue; it goes between the tissue and the tooth. So far, the response has been excellent.

What’s not so good
As the anaesthetic is delivered under a fair pressure load, there is a bit of flow back up alongside the tooth and the patient gets the taste of the anaesthetic. It’s quite bitter but you simply flush that away. Also, because the anaesthetic is under pressure, it can be a little bit tender the next day. I explain these negatives to the patient but they have never knocked it back. They consider the lack of numbness and the profound onset of the anaesthesia much more important.

Where did you get it
Erskine Dental.

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  1. There is definitely a place for this option. The main drawbacks are:
    1. The anaesthetised tooth is slightly elevated in the socket which puts it in hyperocclusion
    2. There is no indication that the tooth is actually anaesthetised until the bur is cutting demtin
    Articaine is definitely the best anaesthetic for this technique because it diffuses so well through bone

  2. This article on the ligmaject was on a link for a laser!!! Like to look at the laser. I use my Ligmaject but mainly for extraxtions as post operative sensativity after this for routine fillings is more common than I like.
    John Jacob


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