CHANGES IN PERIODONTAL-DISEASE INDICATORS IN 35-YEAR-OLD OSLO CITIZENS FROM 1973 TO 1984

Abstract Periodontal disease indicators were evaluated according to the periodontal treatment need system (PTNS) in random samples of 35‐year‐old citizens of Oslo in 1973 and 1984. The study indicated that although periodontal disease was a common finding in both samples, there was a significant reduction in score C (indicating need for complex periodontal treatment) in 1984 compared to 1973. Whereas 37.9% of the subjects showed inflamed pockets deeper than 5 mm (score C) in 1973, only 22.9% scored C in 1984 (non‐Caucasians excluded) This reduction was most pronounced in females. The mean number of C‐quadrants in subjects needing complex periodontal treatment was also reduced from 2.0 in 1973 to 1.7 in 1984. Further analyses of the 1984 sample showed that the mean number of C‐quadrants was significantly lower in subjects with low OHI‐S scores and in regular dental visitors, whereas sex, years at school, toothbrushing frequency, interdental cleaning habits, previous periodontal therapy, self‐experienced need for treatment, health attitude or smoking habits, did not seem to influence the prevalence of score C. Copyright © 1990, Wiley Blackwell. All rights reserved