An electroless plating method for providing a thin adherent substantially continuous metallic layer over an osseous substrate such as a tooth structure. The method comprises contacting the substrate with an aqueous plating mixture containing a water-soluble salt of a metal selected from the group consisting of gold, silver, copper, nickel, platinum, palladium and tin, and a reducing agent for the metal ions of said salt. The plating mixture is maintained in contact with the substrate for a time sufficient for the metallic layer to form thereon. The metallic layer so provided is adapted for subsequent application of a tooth restorative material such as a dental amalgam for carrying out a tooth restoration.