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.