Abstract: The disclosure features compositions that include a material featuring three calcium phosphate phases that form one or more integral units of a solid, where a first one of the three phases includes one or more regions formed of hydroxyapatite, a second one of the three phases includes one or more regions formed of ?-tricalcium phosphate, a third one of the three phases includes one or more regions formed of amorphous calcium phosphate, and where at least some of the regions corresponding to the first, second, and third phases contact one another in the one or more integral units of the solid.

Abstract: The disclosure features methods that include obtaining a first plurality of particles that include calcium carbonate, where the particles have a distribution of sizes between 8 mm and 12 mm, and heating the first plurality of particles to a temperature of between 900° C. and 1200° C. for a time period of at least 1 hour to generate a second plurality of particles that include calcium oxide.

Abstract: The disclosure features methods that include obtaining a first calcium hydroxide solution that includes a first concentration of calcium ions and a second calcium hydroxide solution that includes a second concentration of calcium ions, adding a phosphoric acid solution to the first calcium hydroxide solution to generate a combined solution featuring an aqueous suspension of calcium dihydrogen phosphate particles, and adding the second calcium hydroxide solution to the combined solution to form a product solution that includes an aqueous suspension of particles of a calcium phosphate composition.