Oral and written instruction of oral hygiene: a randomized trial

Background: This randomized, evaluator-masked, controlled study evaluates the effectiveness of oral in contrast to written instruction of oral hygiene. Methods: Eighty-three students without clinical signs of periodontitis were randomly assigned to either a control group or one of three experimental conditions: 1) written instruction, 2) standardized oral instruction, or 3) individualized oral instruction. Plaque and bleeding indices were assessed to analyze intervention effects on oral health and oral hygiene skills. Measurements took place at baseline and 4 weeks after intervention. Results: Groups differed significantly with respect to gingival bleeding and were tentatively significant with respect to oral hygiene skills. Participants who had received oral individualized instructions showed the best results. Conclusion: A gradient of effectiveness of the instruction methods was observed with most favorable results for the individualized instruction.