This study was undertaken to determine whether the addition of calcium sulfate to toothash material (Toothash : plaster of paris=2 : 1) would improve its stabilizing property without adversely affecting its osteoconduction. The radiographic and histologic examinations of bone response of this composite material was performed after 1-, 3-, 5-, 8-, and 12-week implantation in calvaria of rats. No sign of extensive inflammatory response was detected. No movement could be observed with this composite material. Creeping substitution was observed in the surgical site. The direct union between toothash and growing bone after 12 weeks of implantation was observed in the defect margin. We could observe this composite implant material is resorbing slowly as time is over.