A longitudinal study on the effects of dental health education on oral hygiene and tooth decay in primary school children

During the period 1989-92 a research programme was carried out in order to evaluate the importance of oral hygiene education. The aim of the study was to teach oral hygiene to 40 children aged from 6 to 7 years and to verify the results obtained by a longitudinal study. All subjects were monitored for 3 years and the data we found were compared with those from a control group. Since it was not ethically correct to choose a control group made up of subjects deliberately not educated in oral hygiene, 40 children firstly enrolled in the education programme in 1991 were matched (same sex, age [+ or -6 months] and social conditions) with each child of the study group. In 1989, 1991 and 1992 lessons in oral hygiene were held with the help of videotapes, slides and composed pictures, as well as of an enlarged model, which was used to explain how to brush teeth correctly. At the same time, the children were examined by dentists with regard to oral hygiene conditions and dental decay. The plaque index and the df/t index (where 'd' indicates the number of decayed deciduous teeth, 'f' those filled and 't' the total number of milk teeth) were calculated. Concerning the plaque index, the statistical analysis performed using the Wilcoxon signed rank test showed a highly significant difference within the study group before (1989) and 2 years after (1991) the oral education programme. A second education course did not improve further the plaque index in the subjects of the study group.