title: Contribution to the problem of professional decay of the teeth and periodontium. Part I--Methods.
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D003604:Czechoslovakia; D003731:Dental Caries / Q000139:chemically induced / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000139:chemically induced / Q000453:epidemiology*; D009911:Oral Hygiene Index; D010510:Periodontal Diseases / Q000139:chemically induced / Q000453:epidemiology*; D012737:Sex Factors