Just depends on how the tooth is infected. If it is infected into the root of the tooth than one would need to have a root canal or have the tooth removed. Other wise it would be maybe just a crown.
An infected tooth must be treated immediately with anitbiotics from a dentist or physician. Once the infection is under control the tooth must be treated via dental procedures.
The treatment for a tooth with an abscess is a root canal treatment. This is when the pulp and the infection are cleaned out of the root canal and then the space this creates inside the root is completely filled by the dentist.
It just depends on how bad the tooth is. Most of the time the dentist will do a root canal (which is not as bad as everyone says) and then they put a crown on top. If the tooth is in bad shape they will sometimes just pull the tooth.
Depends on the individaul case. Baby tooth? Permanent? Able to be saved and servicable? Typically antibiotics and some type of pulp therapy or extraction.