A longitudinal study of multiple approaches to dental health education.

An evaluation was made of the separate effects on oral hygiene of token reward treatments, discovery (project) learning, and plaque staining feedback demonstrations with children in the first through fifth grades. Both short- and long-term effects were assessed in an open classroom setting. Twenty classrooms were non-randomly assigned to treatment and control groups. Plaque scores were recorded according to the Podshadley Patient Hygiene Performance Index (PHP) at time T0, before initiation of any of the educational interventions; and again at times T1, T2, and T3; 7 days, 74 days and 255 days, respectively, following cessation of the educational interventions. The combination of dental health interventions at this school had short-range effects at every grade level, and those effects persisted for 9 months among the third and fourth graders. It was not possible to identify which of the various treatments produced the observed differences, although the project learning method was generally less effective. A linear regression analysis was used to evaluate the shifts in oral hygiene behavior, a method not previously used in studies of this type.