A cluster randomized controlled trial testing the effectiveness of a school-based dental health education program for adolescents.

OBJECTIVES: This trial investigated the value of a school-based dental health education program in terms of changes in knowledge, reported behavior, and plaque scores.

METHODS: A total of 2,678 pupils with a mean age of 12.1 years attending 28 schools participated in a school-based dental health education program. The study used a cluster randomized controlled study design. The health service administrators stipulated that all participants receive the intervention; to meet this requirement, a rolling program of two six-month periods was utilized. During the first six months, half the adolescents received the intervention program, the other half acting as controls. Throughout a further six-month period, all participants received the intervention program. This research design allowed comparisons between participants receiving the program for six and 12 months. At baseline, six, and 12 months, a random subsample of 40 children in each participating school had their plaque scores recorded and a questionnaire was used to record their knowledge of dental health and reported dental behavior.

RESULTS: The analysis used the subjects clustered within the schools, which were the units of randomization. The intervention program produced statistically significant improvements (P < .001) in knowledge about periodontal disease and the frequency of sugar intake and dental caries in both assessment time periods. The reported frequency of brushing did not change, but the group who had received 12 months of the intervention were more likely (P < .05) to brush for over a minute. At six months the early intervention group had a statistically significant, 13 percent reduction in the mean proportion of sites with plaque compared with the late intervention group (P = .043). This difference was sustained at 12 months (P = .037).

CONCLUSION: This cluster randomized control trial demonstrated that the intervention program resulted in an improvement in knowledge of dental disease and an increase in the reported duration of brushing. These improvements were accompanied by a significant improvement in oral hygiene and a reported reduction in gingival bleeding.