A potent inhibitor for bone resorption, the gem-bisphosphonate zoledronate, has been chemically associated with calcium-deficient apatites. The ability of such materials to release the zoledronate, resulting in the inhibition of osteoclastic resorption, is demonstrated using a specific in-vitro bone resorption model. The resorption activity is typically characterized by the formation of lacunae on the surface of dentin slices (see Figure).