ABSTRACT
The contribution of the tissue components in the healing of bony defects after irradiation was studied using demineralized bone powder [DBP] prepared. In this study 18 rats were divided into two groups, nine rats each. The second group was irradiated after three weeks post-irradiation. The operation was done with two cavities, one filled with DBP and the other one was left empty. The second group was operated without irradiation, then after two weeks from the surgery, three rats were killed, and the same thing was done after four weeks and eight weeks. The specimens were fixed, decalcified and processed routinely for H and E. It was found that the unirradiated bony defect with DBP showed the best healing involving the quantity and quality of bone filled defects, followed by the unirradiated bony defect without DBP, then the irradiated bone defect with DBP, and lastly, the irradiated bone defect without DBP that had the least quality of new bone