Objectives: Allogeneic dentin have been studied for their potential use as bone substitute. A new method was reported for processing allogeneic dentin chips that results in bioactive material for repair and regeneration of bone. Methods:Extracted guinea pig's teeth was processed mechanically to obtain dentin chips and then sterilized. Mandibular bone defects were created in guinea pigs, left as controls, another defects were filled with dentin chips and others were filled with BMP and dentin chips. Results:The dentin chips showed excellent biocompatibility, stimulated formation of new bone and was completely incorporated into the new bone. Conclusions:These results indicate that the allogeneic dentin may be an alternative material to autogenous bone for treating mandibular bone defects by grafting. Significance: Allogeneic dentin have the potential to be used as suitable substitute in bone repair and regeneration.   Key words: Bone, grafts, dentin, bone substitute.