[header] How to numb a tooth [title] Take an over-the-counter-painkiller. [step] A painkiller like ibuprofen or acetaminophen should be your first step in trying to numb a painful tooth. These painkillers will alleviate the pain from your tooth, and should also decrease any swelling in the infected area. 
These are all readily available at your local pharmacy. [substeps] If you're treating a toothache in a child younger than 18, do not give him or her aspirin.