Pain around the tooth is one way to know for sure that a tooth is infected and swollen gums are another sign that the area around the wisdom tooth is infected. Pain around the tooth and cavities in the tooth are a sign that the tooth itself is infected.
if any tooth is infected you will know by the pain you are in. tooth pain is the second worst pain a person can have (close second only to labor) no pain killers will take the pain away, not even powerful tranquilizers.