Periodontal Disease is a very common disease in cause by poor oral hygiene or genetic predisposition by the gums or the tooth. Without periodontal treatment, you are risk of losing your teeth.
The dentist that should do the therapy should be a specialized. Gums should be diagnose for any disease using various apparatus. Also the dentist should ask the patient carefully regarding their oral hygiene to better investigate the cause and solution to the disease. Then examine the mouth using a special tool bag. 3 millimiters depth of the pocket is considered normal, rather than 4 which is dangerous to the tooth out.
Consult your specialist immidetely if you see signs of periodontitis to avoid further infection.