Look for the early signs of having lost a filling or dislodged a crown: pain when cold air, food, liquids or your tongue touch the tender area.
Wash your hands thoroughly with antiseptic soap.
Put on latex gloves if you are treating someone other than yourself.
Prepare a mixture to use as temporary filling if you do not have a premixed temporary filling compound from your dentist. A standard mixture available with some first aid kits is a mix of zinc oxide powder and oil of cloves, but you can improvise by rolling a ball of sugarless gum, ski wax or candle wax.
Rinse the mouth thoroughly with disinfected water.
Apply a drop of oil of cloves (also known as "eugenol") to the hole in the mouth. This will reduce the pain.
Roll the temporary filling into a small ball and place the ball gently into the exposed area, making certain to cover any exposed tissue.
Bite down, lining the tooth up with the tooth above or below it.
Wait for the filling to harden if you are using a premixed filling or a mixture of zinc oxide powder and oil of cloves.
Evacuate immediately and see a dentist.