Abstract: The present disclosure concerns a mineralized tissue adhesive or filler composition comprising an intermolecular crosslinked osteopontin protein for treating an exposed surface of a mineralized tissue. The mineralized tissue adhesive or filler composition can be added directly on the exposed surface of the mineralized tissue or on a layer of monodisperse OPN protein which has been deposited on the exposed surface of the mineralized tissue. The present disclosure also includes methods and kits of using the mineralized tissue adhesive or filler composition especially in dental applications. The present application also provides dental coatings, fillings, bondings and veneers comprising the mineralized tissue adhesive or filler composition described herein.