We applied hydroxyapatite (HAP) grafting clinically for 10 patients with defects produced by a curettage of benign bone tumors. The average follow up after surgery was 29 months (range 4 to 53 months). Physical and hematological findings during this period did not show any abnormalities. The radiographic evaluation of the incorporation of the implant was divided into four stages based on marginal findings and homogeneity of the grafted HAP. The margin of HAP became possibly unclear (stage II) an average of 3 months after surgery, and almost homogeneous with the surrounding bone (stage III) 11 months after surgery.