The current study was conducted on twelve mongrel dogs where standard surgically created defects about 15 mm in diameter were made at the mandibular horizontal ramus using trephine bur and unibevelled chisel to facilitate removal of the outer cortical plate. The created defect was deepened by removal of the underlying cancellous bone with great caution to avoid endangering of the inferior dental canal. The surgical procedures were performed bilaterally, where the right-sided defect was obliterated with bioglass in group one and a mixture of autogenous bone and bioglass was used to fill the effect in group two, while the left sided defect was left to be filled with blood only and used as the control side. At designated intervals of one month, three months and six months, two animals from each group were sacrificed and the mandibles were dissected and surgical sites were prepared, sectioned and stained with hematoxin and eosin and submitted to qualitative analysis to asses the bone healing for the three groups in each follow up interval. The histopathological results revealed significant difference between the three groups all over the three intervals. After one month postoperative, the specimen at the left side in group two (autogenous bone and bioglass group) showed thin bone trabeculae which are united with each other while in group one (bioglass group) there was only osteoblastic differentiation with smaller sized trabeculae than in group two, however in the control group, it was only filled with granulation tissue that contained few dilated blood vessels At three months postoperative in group two (autogenous bone and bioglass) numerous bone trabeculae was shown with no evidence of osteon formation, while in group one the bone trabeculae formation was less than group two. At six months postoperative, the defect in group two was filled with large sized bone trabeculae which are united with each other and with he original bone with evidence of osteon formation, while at group one, it was filled with medium sized trabeculae which are united with each other and with original bone but still with on evidence of osteon formation. In the control group the bone trabeculae was less than in the other groups and the marrow spaces was wider. Analyzing the findings of the present study , the following was concluded: at all the three follow up intervals, the addition of the autogenous bone to bioglass has resulted in increased amount of bone formation at the created defects, especially at the end of the six month postoperative follow up period. This denotes the value of mixing autogenous bone to bioglass in an added benefit of reducing the volume of the needed autogenous bone, thus reducing the probability of donor site morbidity. Accelerating the rate of healing at bony defects and preparing the mandible to receive dental implants or removable prosthesis at an earlier time.