Survey of periodontal disease among workers in Tianjin using Ramfjord's Periodontal Disease Index (PDI).

An epidemiologic study of periodontal disease according to Ramfjord's PDI among 2284 workers was performed in Tianjin in 1982. This study included 1066 men and 1218 women, aged 18-50. The prevalence of gingivitis and periodontitis was 89.5% and 44.4%, respectively. Only 28 workers were free from periodontal disease. Gingivitis and periodontitis were highly prevalent in both sexes, but men had more severe gingivitis and periodontitis than women. The better oral hygiene of the women may account for this difference.