School‐based intervention to promote preadolescents’ gingival health: a community trial

Abstract

Evaluation of the effectiveness of a school-based oral health promotion intervention on preadolescents' gingival health. A community trial designed for a 3-month intervention study in a representative sample of 9-year-olds (n = 457) in 16 schools in Tehran, Iran. The schools were randomly assigned to three intervention groups and one control group, each group comprising two boys' and two girls' schools. The first group of children (n = 115) received intervention via class work, solving a set of puzzles containing oral health messages, under supervision of their health counsellor. The second group (n = 114), intervention via parents, included an oral health education leaflet and a brushing diary for supervising the child's tooth-brushing; the third group (n = 111) received a combination of both these interventions. The control group (n = 117) had no intervention. Effects of the intervention were assessed as changes in dental plaque and gingival bleeding. Improvements in gingival health were recorded when half of the index teeth with plaque at baseline became clean (acceptable oral hygiene) or when all index teeth with bleeding at baseline became healthy (healthy gingiva). Statistical analysis included chi square, anova, t-test, Number Needed to Treat (NNT) and generalized estimating equations (GEE). At baseline, none of the children were free of plaque and all except for three boys had bleeding. After the trial, acceptable oral hygiene was more frequent in the parental-aid (P < 0.001) and the combined groups (P < 0.05), and healthy gingiva in both groups (P < 0.001) in comparison with the control group. Outcomes in the class-work group did not differ from those in the control group. The GEE models confirmed a strong intervention effect on healthy gingiva in both groups where parents were involved: parental-aid group (OR = 7.7, 95% CI: 2.2-27.7) and combined group (OR = 6.6, 95% CI: 2.0-22.1). In all intervention groups more girls than boys achieved healthy gingiva (OR = 2.5-2.6). Parents' education showed no impact on the outcome. When a school-based oral health intervention involves parents it may result in a significant improvement in the gingival health of preadolescents with poor gingival health at baseline.