Una de las alternativas para la reconstruccion de dientes altamente destruidos son los postes prefabricados, elaborados con diferentes materiales, los cuales permiten la reconstruccion del munon con resina, amalgama o ionomero de vidrio, para finalmente retener una corona que reproduzca la forma y la funcion. Esta investigacion evaluo el comportamiento adhesivo de la resina de reconstruccion de munon (Bis –core Bisco) con dos sistemas de postes prefabricados. Se utilizaron dos grupos de 10 especimenes cada uno (fibra de carbono y fibra de vidrio) con la respectiva reconstruccion de munon en resina, sometidos a una carga ciclica de 98 newton, en una maquina de levas, simulando el ciclo masticatorio. No se encontro diferencia significativa en el comportamiento de cada tipo de poste con respecto a la resina. La resina fallo en 4 de las 20 muestras, 3 de las cuales fueron cohesivas y una adhesiva. La falla predomino en el poste, ubicandose en la porcion coronal de los postes de fibra de vidrio y mas apical para los postes de fibra de carbono. Se concluyo que la interfase poste munon es fuerte y que bajo carga ciclica la falla que se produce en los postes de fibra de carbono es mas de tipo parcial y se ubica en el tercio medio; los postes de fibra de vidrio presentan una falla similar pero ubicada en el tercio cervical. Adicionalmente el tiempo promedio de duracion de los sistemas fue de 4 a 6 anos. ABSTRACT The prefabricated post are one of the alternatives to restore a very damaged teeth, those post are made of different kind of materials which allow the reconstruction of the core with materials as composite, amalgam and glass ionomer all this to create an ideal preparation to support a permanent fixed crown that will restore not only aesthetics but also function. The present investigation tested the adhesive behavior of one core composite material (Bis Core –Bisco) with two different kind of prefabricated post (Carbon fiber post and glass fiber post). They were ten specimens for each group and they were tested under cyclic load of 987NW in a Lavas machine simulating the masticatory cycle. There were not an statistically difference between the groups in relation of the core restoration but the core fail in 4 of the 20 specimens, 3 of them in a cohesive way, on the other side the more common failure was in the post, in the coronal third of the glass fiber and more apical on the carbon fiber. It was concluded that the adhesive interface between post and core is very solid and that under cyclic testing the failure for the carbon fiber post is more partial and in the middle third beside the glass fiber post which its failure is also partial but occur in the cervical third, additionally the average time of longevity under this circumstances was between 4 and 6 years.