Longevity of teeth in patients susceptible to periodontitis: Clinical outcomes and risk factors associated with tooth loss after active therapy and 30 years of supportive periodontal care.

(i) Periodontal therapy and a stringent SPC are effective in maintaining most of the teeth in patients with moderate/advanced periodontitis for 30 years, and (ii) age, gender, molar teeth, pocket depth, bone loss, and the presence of a root canal treatment and a crown are prognostic factors associated with tooth loss.