Can you tell me how to treat a dental abscess?

Determine cause...: .. From a necrotic nerve or from a periodontal defect? Once you determine the cause of your problem, then you can treat it effectively. Since you may not be able to personally determine the cause, my advice would be to call a local dentist for an appointment. They're trained to diagnose and treat these problems.

See a dentist: to drain the dental abscess. The infection may spread to your jaw, cheeks, sinus and to other areas of your head and neck. See your dentist for examination, x-rays and treatment. It is a very common procedure.

See a dentist: and have them treat it is the only treatment that will work

Dental abscess: If the tooth is salveagable long term have the appropriate treatment to save it by a qualified dentist, otherwise have the tooth extracted.