CHANGES IN PERIODONTAL TREATMENT NEEDS - A FOLLOW-UP-STUDY OF OSLO CITIZENS FROM THE AGES OF 35 TO 50 YEARS

A random sample of 35-year-old subjects from Oslo took part in a denta l survey in 1973 and were re-examined in 1988, Eighty-one subjects (85 %) attended the final examination. The need for periodontal treatment was assessed by the Periodontal Treatment Need System (PTNS), and the oral hygiene by the Simplified Oral Hygiene Index (OHI-S). The partici pants attended a structured interview and answered a questionnaire abo ut general and dental health habits as well as psyche-social factors. Only small changes in the distribution of subjects in the different PT NS categories were found to have taken place during the 15 years. In 1 973, 56.8% were in need of scaling (Class B) and 32.1% had one or more deep inflamed pockets (Class C), and in 1988 the scores were 54.3% an d 30.1% respectively. A logistic regression model was used to study th e associations between risk factors and increased treatment need, as e xpressed by increase in the number of C-quadrants. Increased number of C-quadrants was positively associated both with short duration of edu cation and with no interdental cleaning. Using a socio-ecological mode l for periodontal diseases, variables describing the items ''behaviour '' and ''environment'' were found to be most closely associated with i ncreased need for periodontal treatment.