a porous aluminum-calcium-phosphorus oxide (alcap) ceramic has been developed for potential use in correcting bone defects. the material is at least partly resorbed and appears to have acceptable biocompatibility and toxicity characteristics for its intended applications. alcap ceramics are fabricated by calcining mixtures of aluminum, calcium, and phosphorus oxide powders and sintering the compressed blocks from calcined particles of the desired size. by varying the dimensions of the die, particle size, sintering time, and temperature. alcap ceramics have been fabricated that may be useful for repairing a wide variety of bone defects. the fate of alcap ceramics in both in vitro and in vivo environments has been studied by means of chemical analysis of tissues, chemical and enzyme analysis of implants, radiography, radioactive isotope uptake, scanning electron microscopy, energy-dispersive x-ray analysis, and histology. keywords: porous implants, bone repair, aluminum-calcium-phosphorus oxide (alcap) ceramics, mutagenicity, spinal fusion, resorption, oral surgery, maxillofacial surgery, bones, surgical implantation. reprints. (jes)