Duong HY, Schmid E, Ramseier CA, Suvan JE, et al. Periodontal disease progression in the second half of life and following a single
episode of scaling and root planing: A clinical study in the Sri Lankan tea
plantation cohort with documented clinical parameters for more than 40 years. J Periodontol 2022;93:45-56.
PMID: 34405417