Periodontology is a branch of dental medicine that deals with prevention and curing disease of periodontium. Periodontium consists of bone, periodontal ligament and gums. It supports the tooth.
Periodontal diseases are caused by bacteria in dental plaque. Those bacteria release toxins on which periodontal tissues react with inflammation. That inflammation is presented as redness, swelling and bleeding gums. We call that gingivitis. Progress of the disease spreads the inflammation into deeper tissue which causes retraction of the gums and bone loss. We call that periodontitis. Eventually it may lead to tooth loss.
There are few methods of periodontal treatment depending on severity of the case. In very mild cases supragingival removal of dental plaque will suffice, subgingival removal of dental plaque is needed in moderate cases and surgical methods are used in advanced cases. The main prevention method for periodontal disease is good oral hygiene, regular dental exams and removal of dental plaque.