title: Research explores periodontal disease.
mesh_terms: D000818:Animals; D003728:Dental Calculus / Q000209:etiology*; D006801:Humans; D066298:In Vitro Techniques; D009316:National Institutes of Health (U.S.); D010510:Periodontal Diseases / Q000175:diagnosis* / Q000382:microbiology*; D010512:Periodontal Index; D011817:Rabbits; D014481:United States