One-year oral health outcome of a community-based trial in schoolchildren aged 6–7 years old in Tehran, Iran

Promoting schoolchildren’s oral health is important, particularly in developing countries. This study was conducted to monitor the oral health of schoolchildren aged 6–7 years old following the implementation of an oral health promotion program in Tehran, Iran. The protocol was registered in the Iranian Registry of Clinical Trials (Code: IRCT20090307001749N4). A cluster random sampling method was applied, and the schools were randomly allocated to intervention and control groups. An intervention package consisting of a one-day workshop for parents and supervised toothbrushing for children was employed. In both groups, the Caries Assessment Spectrum and Treatment (CAST) and Oral Hygiene Index Simplified (OHI-S) were evaluated at baseline and at one-year follow-up in addition to the questionnaire data. Clinical data were collected by calibrated examiners at both intervals (Kappa = 89.8%, 87.68%) and analyzed using the SPSS software ver. 22.0. Of 739 children included at baseline, 593 were re-examined after one year (response rate = 74%). According to the Generalized Estimating Equation (GEE) analysis, considering the confounding effect of time, significantly more children in the control group had deciduous molars with a score of 3 and higher compared to the intervention group (OR = 1.79; 95% CI:1.17–2.73, p = 0.007). The oral hygiene status of the children significantly improved in the intervention group compared to the controls (B = -0.27; 95% CI: -0.45 –-0.08, p = 0.005). After one year, the improvement in the oral health-related attitude of parents and children’s oral health behavior was marginally significant in the intervention group compared to the control group [0.2 (0.17) vs. -0.13 (0.05), p = 0.096] and [0.06 (0.06) vs. -0.05 (0.04), p = 0.09], respectively. However, the impact on the oral health-related knowledge and self-reported behavior of the parents was not significant. In the intervention group, children had less caries and a better oral hygiene status compared to the controls after one year.