The potential for bioactive ceramic surgical implants has resulted in a number of studies conducted to provide physical, mechanical, chemical, electrical, and biological property characteristics. Previous investigations are now providing the basis for ASTM F-4 standards associated with the basic material properties as they relate to implant device applications. Extensions of data on particulates and device-oriented research have resulted in coatings on higher strength substrates. The theoretical advantages of calcium phosphate ceramic coatings are multiple and include: elements normal to the biological host; moduli of elasticity similar to bone; structural bonding to bone capable of transferring tensile forces; minimal conductors of heat, electrons, and substrate elements (a physical, chemical, and electrical barrier); a color similar to bone; and an established profile for host biocompatibility. Possible limitations of coatings for musculoskeletal load-bearing application can be directly related to mechanical and biological interaction; e.g., (1) inherent fracture and fatigue strengths of the ceramic-metal interface; and (2) a susceptibility to time-dependent biodegradation by the host that is mediated by cellular- and enzymatic-based interactions during normal bone modeling and remodeling. The current emphasis on standards development should provide a basis for comparing existing and new bioactive particulates and coatings with one another, and, subsequently, correlations with clinical investigations.