A sample of 8000 persons was drawn to represent the Finnish population aged 30 years and over. The participation rate was 89.9%. Root caries was recorded when the lesion was obviously soft and more than half of it was located on cementum. Lesions adjacent to fillings were not included. The reproducibility and the standard of the clinical recordings were tested by reexamining 20% of the studied population 2-6 months after the first clinical examination. The overall prevalence of root caries was 21.6% for men and 14.5% for women. The prevalence increased for both sexes almost consistently with age. Root caries was found 1.6 times more often among men than women. Among men 2.23% and among women 1.19% of teeth were affected by root caries.

Of a representative sample of 8000 persons aged 30 and over living in Finland, 3875 users of removable dentures were examined. The condition of the oral mucosa was recorded during clinical examinations. The prevalence of oral mucosal lesions associated with removable dentures was analyzed according to age, sex, place of residence, geographical region of living, and type and location of prosthesis. Lesions were found in about 50% of the denture wearers. Women were affected more often than men. The prevalence of lesions decreased with age and differed slightly according to region of living and place of residence. Compared with the wearing of partial dentures, wearing complete dentures increased the risk of lesions. Only one of the 72 denture users who wore a denture with metallic base plate had oral mucosal lesions associated with wearing a denture.

A representative sample (n = 8000) was drawn from the population aged 30 years and over, registered as living in Finland. Periodontal disease status was recorded according to the modified Periodontal Treatment Need System (PTNS). Plaque retentions were examined separately. Of the subjects with four or more teeth 3.4% had a healthy periodontal status, while 10.2% of the jaw quadrants were healthy. Plaque retentions were found in 96.6% of the subjects and 90.9% of the jaw segments. Periodontal treatment need was calculated in three ways and was 195 +/- 111 (S.D.) min when the calculation was based on WHO recommendations (1978). Number of teeth, age, sex, caries and filling scores, and education explained about 30% of the treatment need when tested by multiple linear regression analysis.

The dimensionality of health behavior is disputable. In the present study an effort was made to shed more light on this problem. Interview data were obtained from 3209 13--19-year-old Finnish adolescents concerning the subjects' smoking habits, use of alcohol, physical activity, toothbrushing and dietary habits. A clear positive relationship was observed between toothbrushing and the use of sugar-containing snacks. Use of alcohol seemed to have slight adverse effect on toothbrushing. Smoking was also weakly related with sporadic toothbrushing. Sports-oriented girls seemed to be regular toothbrushers. It was concluded that the possible comprehensive nature of health behavior should be more appreciated.

The aim of this study was to analyze oral hygiene habits among Finnish adolescents with regard to age, sex, residence, socioeconomic factors, school career and success. A representative sample of 3209 Finnish adolescents, 13-19 years of age, was drawn. The data were collected by mail surveys in February and September 1977. Participation percentages were 88 and 79. The proportions of daily brushers were 89% in girls and 57% in boys. Toothpicks were used sporadically by every second adolescent but daily by 3% only. Dental floss was used sporadically by 10% of the adolescents but daily by 1% only. In this respect girls were more assiduous than boys. Frequency of toothbrushing clearly increased with age. Girls brushed their teeth significantly more often than boys. The influence of socioeconomic factors was consistent in boys but almost nonexistent in girls. Children of white-collar workers reported better oral hygiene habits than children of blue-collar workers and farmers. Urban adolescents reported better habits than rural adolescents. School success correlated positively with toothbrushing frequency in the younger age groups. Dental health education given by a dentist, a teacher, a hygienist or a nurse had poor correlation with the oral hygiene habits of Finnish adolescents. It was concluded that dental health education should be more directed towards boys, especially at ages 13-15. The education should be planned so that the dental health education better reaches youth of rural areas and lower social classes.