TISSUE-RESPONSE TO FAST-SETTING CALCIUM-PHOSPHATE CEMENT IN BONE

Fast-setting calcium phosphate cement (I;SCPC) is a promising new bioa ctive cement with a significantly short setting time (approximately 5- 6 min) compared to conventional calcium phosphate cement (c-CPC) (30-6 0 min) at physiologic temperatures. As a result of its ability to set quickly, it is applicable in surgical procedures where fast setting is required. In this study, FSCPC was implanted in rat tibiae to evaluat e tissue response and biocompatibility. FSCPC was converted to hydroxy apatite (HAP) in bone faster than c-CPC in the first 6 h. By 24 h, sig nificant amounts of both FSCPC and c-CPC had been converted to HAP. Th e conversion of FSCPC into HAP further proceeded gradually, reaching 1 00% within 8 weeks. Infrared spectroscopic analysis disclosed the depo sition of B-type carbonate apatite, which is a biological apatite cont ained in human dentin or bone, on the surface of the FSCPC. Histologic ally, FSCPC showed a tissue response similar to that of c-CPC. A sligh t inflammatory reaction was observed in the soft tissue apposed to bot h cements in the early period, and new bone was formed along the surfa ce of the FSCPC at the adjacent bone. However, no resorption of either cement by osteoclasts or macrophages was observed within 8 weeks. We conclude that FSCPC is superior to c-CPC in clinical applications in o ral and maxillofacial, orthopedic, plastic, and reconstructive surgery , since it shows a faster setting time and higher mechanical strength in the early period that are required in these surgical procedures, as well as osteoconductivity and excellent biocompatibility similar to t hat of c-CPC. (C) 1997 John Wiley & Sons, Inc.