Periodontics is the specialty of dentistry that studies the prevention, diagnosis and treatment of diseases or abnormalities that affect the tissues surrounding the teeth, gums and bones that support the teeth. The main periodontal diseases are gingivitis (inflamed and bleeding gums without affecting the bone) and periodontitis (bone destruction causing teeth mobility or loss).
The ideal situation means a gum covering the whole root area and the crown as the only not covered part of the tooth. There are no inflamed gums or pains and the tooth is surrounded by a fix gum called attached gum.
Periodontal diseases may cause gingival recession, which means teeth roots became uncovered.