Where There Is No Dentist 2012 147
1. Keep the cavity dry. The cavity and the area around it must be dry
so you can see what you are doing. Just as important, cement stays
longer inside a dry cavity.
Place cotton between the cheek and
gums to keep the area dry. Put some
cotton under the tongue when you
work on a lower tooth.
Use whatever kind of cotton you
have: gauze, wool, or even rolls.
Change the cotton whenever it
Keep the cavity dry while you work.
Wipe the inside of it every now and
then with a bit of cotton.
Then leave a piece of cotton inside
the cavity while you mix the cement.
2. Lift out the decay. You do not need to remove all of the decay on the
bottom of the cavity. If you try to clean out all of the decay, you might
touch the nerve.
However, you must remove all of the decay from the edges of
the cavity. Otherwise, germs and food can go between the cement
and the cavity and keep the decay growing inside. For ART
(pages 152–155), it is especially important to remove all the decay
from the edges so the filling will stick well.
Use the spoon tool to scrape clean
the walls and the edge of the cavity.
If you find that the part of the tooth at
the edge of the cavity is thin and
weak, break it deliberately. That
makes for stronger sides to hold
onto the cement. You can use the
end of your filling tool to break
the edge but it is much easier with a dental hatchet,
which is less likely to bend.
Use the spoon tool to lift out soft decay from inside
the cavity. Be careful not to go too deep and touch
the nerve at the very bottom of the cavity. This
takes practice. If the tooth hurts when you do this,
stop and inject some local anesthetic.