Here's how you can use garlic to treat a toothache:
For toothaches caused by sores or infections, rubbing half a clove of garlic on it for seven to ten minutes can help to relieve the discomfort. When the pain begins, chew carefully on a clove of garlic to release the juice. In around 15 to 30 minutes the allicin in the juice will take effect and the pain will disappear.
Garlic is a great emergency remedy for a toothache, especially when it hits on a weekend when all the dentists are closed. But remember that this is only an emergency measure and not a cure. If your toothache persists, you should go to a dentist as soon as possible. Toothaches come in many different forms and a home remedy is not always enough. So when in doubt, err on the side of caution and seek professional help.