Periodontitis is caused by bacteria in plaque deposite on gum and teeth. Leading to gingival inflammation and alveolar bone damage.
First sign is bad breath and gum bleeding. Ignoring what happen will increase the severity of disease, advance alveolar bone determination by bacteria, tooth mobility and tooth loss eventually.
Deep cleaning of teeth and root planning to get rid of bacteria is necessary to treat the disease, which will take several visits. After that the recall to check out and control disease is still needed to prevent recurrent.