Where There Is No Dentist 2012 137
It is more difficult to inject the lower teeth.
The lower jaw bone is thicker. When you inject near the roots of a lower
tooth, the anesthetic is not able to reach its nerve as easily.
Note: You can inject lower front teeth
in young children, or very loose lower
front teeth in adults, near their roots.
To make a lower tooth
completely numb, you must
block the main nerve (a) before
it goes inside the jaw bone.
If you are treating a back
tooth, you must give a
goes to 3
second injection for nerve (b).
See page 140.
These 2 injections also make the
gums around the teeth numb.
WHEN TO INJECT
Inject local anesthetic whenever the treatment you give may hurt the
person. If, after you inject, the person says the tooth still hurts, be kind. Stop
and inject again.
Inject local anesthetic slowly and carefully.
You can then treat a bad tooth and not hurt the person.
HOW TO INJECT*
For a good, safe injection, remember these 5
1. Do not inject local anesthetic
into an area that is swollen.
This can spread the infection.
Also, pus inside the swelling
stops the local anesthetic from
Instead, treat the swelling first (page 94) and take out the tooth later.
2. If the person has a heart problem, do not inject more than
2 times in one visit. Also, it is best not to use an anesthetic with
epinephrine on persons with heart problems. Use lidocaine only, or
mepivacaine 3% only.
* Local anesthetics are the only injections given in the mouth. To learn about injecting antibiotics,
see page 210.