Tissue and cell reactions to implanted root-end filling materials.

The use of root-end filling materials designed to stimulate hard and soft tissue repair in periradicular tissues is highly recommended. The materials should demonstrate good cell and tissue compatibility. The aim of the present study was to compare in vitro biocompatibility and in vivo tissue reaction with calcium hydroxide-based, eugenol-based and mineral trioxide aggregate root-end filling materials. The human osteosarcoma cell line was treated with immersed root end filling materials. The test materials were implanted in rats and the results observed at 6 and 8 weeks. In vitro, the highest survival rate was demonstrated for the mineral trioxide aggregate (p<0.05). In vivo, a radiopaque ring was evident in the calcium hydroxide implants on the eight-week radiograph. Histopathology revealed eugenol-based material with the inflammatory cells around the implant, with fibrous connective tissue forming around the calcium hydroxide-based analog. The mineral trioxide aggregate appears to be well tolerated by the tissue.