The medium-term results of treatment with hydroxyapatite implants

Although the short‐term results of implants with synthetic hydroxyapatite (HA), a bioactive material, have been favorable, few reports have been published concerning medium‐term outcomes for this therapy. The authors recently analyzed data supplied by 37 medical facilities nationwide concerning the outcomes of synthetic HA implants [Bonfil® (BF); Mitsubishi Materials Corporation, Tokyo] in 138 patients followed up for at least 5 years after treatment. When the data were analyzed, the patients were divided into two groups: the disease site‐filling group (62 cases where bone defects created by disease were filled with synthetic HA) and the donor site‐filling group (76 cases where bone defects created by bone donation were filled with synthetic HA). In the disease site‐filling group, synthetic HA was used in combination with autologous bone or autogenous bone marrow donated from the same patient in 77% of cases. In the donor site‐filling group, only synthetic HA was used in most cases. The average follow‐up period after implantation was 7.9 years in the disease site‐filling group and 9.1 years in the donor site‐filling group. Therapy was rated radiographically as “very effective” or “effective” in 81% of patients in the disease site‐filling group and in 89% of patients in the donor site‐filling group. The therapy was not rated as “ineffective” in any case from either group. These results suggest that synthetic HA may serve as a very useful substitute for cancellous bone if used carefully, with its initial strength taken into account. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005