OBJECTIVES: The objective of this study was to evaluate the effectiveness of oral health educational actions in the school context in improving oral hygiene and dental caries in schoolchildren through systematic review and meta-analysis.

METHODS: Clinical trials with schoolchildren between 5 and 18 years old were included. Eligible studies were those which had as outcomes caries, plaque accumulation, gingivitis, toothache or tooth loss and which had been published from 1995 to 2015, in any language. The risk of bias was assessed in specific domains according to the Cochrane Handbook. A meta-analysis was carried out using fixed-effects models.

RESULTS: A total of 4417 references were found, from which 93 full texts were evaluated and 12 included in this meta-analysis. Five studies showed a reduction in plaque levels, and two studies with gingivitis as the outcome found no effect. There was not enough evidence on the effectiveness of the interventions in reducing dental caries.

CONCLUSIONS: Traditional oral health educational actions were effective in reducing plaque, but not gingivitis. There is no long-term evidence in respect of the effectiveness of these interventions in preventing plaque accumulation, gingivitis and dental caries in the school environment.