Hi Nancy,following are some home remedies-
*Mix 1/4-teaspoon of potassium carbonate in 1/2 glass of water and use this solution as a mouthwash. Using it three to four times should reduce the pain in a few hours. This alkaline solution usually destroys the bacteria. For some people clove powder stuffed in the cavity has also helped.
Another home remedy for mouth abscess is, if you have tooth ache or swelling in the gums immediately take to drinking two- three glasses of water and continue drinking a glass or two of water every 20-30 minutes, the pain will start to reduce after a while and will perhaps completely subside.