Statement of Problem: The goal of bone regenerative therapy is to reconstruct the damaged tissues to initial condition, which seems so important in periodontoiogy and implantology. In such therapies, different biomaterials, with some advantages and disadvantages, may by use."nPurpose: The aim of this research was to evaluate the quality, bone trabecular density and thickness of newly forming bone as well as foreign body reaction against Biostite®, in comparison with the control group."nMaterial and Methods: In this experimental study the total number of 5 sheep was operated with"ngeneral anesthesia. At first 10 standard defects were created in 5x5x5mm on the left and right edentulous"nmandibular ridge. Five defects were randomly treated by Biostite®, the remaining five were considered"nas controls. After six months, the sheep were sacrificed and the separated defect areas with intact margin"nwere placed in 10% formaline and prepared for histologic and histomorphometric study. To analyze the"ndata, Mann-Whitney U test was used."nResults: The mean percentage of new bone formation in Biostite® group was statistically more than the"ncontrol group (PO.05). Newly formed bone was vital in both groups which was a combination of"nlamellar and woven types, however, the thickness and density of new bone in biostite® group was more"nthan the controls. Foreign body reaction was observed in Biostite® group."nConclusion: It is suggested that Biostite® synthetic material can be useful in bone regenerative"ntherapies