espanolIntroduccion y Objetivo: Las cifras de los estudios de morbilidad oral indican con frecuencia que las medidas que se toman para lograr el control de la placa dental no son eficaces. El proposito de este estudio fue comparar la eficacia de dos estrategias para el control de la placa dental aplicadas en escolares. Materiales y Metodos: Estudio experimental, realizado en 510 escolares escogidos por muestreo probabilistico y seleccion aleatoria. Los participantes se dividieron en tres grupos: al primero se le aplico la estrategia “Marketing social”(tecnica de higiene bucal acompanada de una campana publicitaria), al segundo, la estrategia “Tradicional”(charlas educativas y capacitacion en tecnica de cepillado) y el grupo “Control” que no recibio ninguna instruccion. Se tomaron pre y postindices gingivale s y de placa bacteriana. Resultados: La comparacion de la estrategia “marketing” con el grupo “control” dio un Riesgo relativo (RR) de 0.85 (IC 0.71-1.02), una Reduccion absoluta de riesgo (RAR) del 10%, un Riesgo Absoluto poblacional (Rap%) de 8% y Numero necesario a tratar: (NNT)de 10. Cuando se comparo la estrategia “tradicional” con el grupo “control” se obtuvo: RR=1.10 (IC 0.95- 1.28); RAR: 6%, Rap%= 4 % y NNT= 16. Conclusion: Los promedios de los postindices de placa bacteriana y gingivales fueron menores en el grupo donde se aplico la strategia “Marketing” (p menor que 0.05). La estrategia” tradicional” no tuvo beneficios adicionales cuando se comparo con el grupo “control”. EnglishIntroduction and Objective: Figures of studies of oral morbidity frequently show that dental plaque control measures are not efficient. The aim of this study was to compare the efficacy of two strategies for dental plaque control in school children. Materials and Methods: This experimental study was carried out in 510 school children selected by means of a randomized probabilistic sampling. Children were divided into three groups. The first was approached by a social marketing strategy (oral hygiene technique accompanied by an advertising campaign), the second received the traditional dental strategy (educational talks and instruction in brushing technique) and the third was the control group which did not receive any instruction. Gingival and pre- and post-brushing plaque index scores were analyzed. Results: The comparison between the marketing strategy group and the control group showed the following results: a relative risk (RR) of 0.85 (95% CI, 0.71 to 1.02), an absolute risk reduction (ARR) of 10%, an absolute population risk (APR) of 8% and a Number Needed to Treat (NNT) of 10. The comparison between the traditional dental strategy group and the control group showed the following results: RR=1.10 (95% CI, 0.95 to 1.28); ARR= 6%, APR% = 4 % and NNT= 16. Conclusions: The averages of gingival and post-brushing plaque index scores were lower in the marketing strategy group (p menor que 0.05). “Traditional” strategy had no benefits whatsoever when compared with “control” group.