A turbine airfoil comprising: a substrate comprising an outer surface and an inner surface, wherein the inner surface defines at least one hollow, interior space, wherein the outer surface of the substrate defines a pressure side wall and a suction side wall, wherein the pressure and suction side walls (24,26) are joined together at a leading edge and at a trailing edge of the turbine airfoil, wherein the outer surface defines one or more grooves that extend at least partially along the pressure or suction side walls in a vicinity of the trailing edge of the turbine airfoil, and wherein each groove is in fluid communication with a respective hollow, interior space; and a coating disposed over at least a portion of the outer surface of the substrate, wherein the coating comprises at least a structural coating, wherein the structural coating extends over the one or more grooves, such that the one or more grooves and the structural coating together define one or more channels for cooling the trailing edge of the turbine airfoil, characterized in that at least one of the channels comprises: an inlet portion that extends partially along the suction side wall, an outlet portion that extends partially along the pressure side wall, and an intermediate portion that extends between the inlet and outlet portions of the cooling channel, wherein the substrate further defines at least one access channel that extends between and provides fluid communication between a respective hollow, interior space and the inlet portion of the cooling channel, and wherein the access channel intersects a base of the inlet portion of the cooling channel. a substrate comprising an outer surface and an inner surface, wherein the inner surface defines at least one hollow, interior space, wherein the outer surface of the substrate defines a pressure side wall and a suction side wall, wherein the pressure and suction side walls (24,26) are joined together at a leading edge and at a trailing edge of the turbine airfoil, wherein the outer surface defines one or more grooves that extend at least partially along the pressure or suction side walls in a vicinity of the trailing edge of the turbine airfoil, and wherein each groove is in fluid communication with a respective hollow, interior space; and a coating disposed over at least a portion of the outer surface of the substrate, wherein the coating comprises at least a structural coating, wherein the structural coating extends over the one or more grooves, such that the one or more grooves and the structural coating together define one or more channels for cooling the trailing edge of the turbine airfoil, characterized in that at least one of the channels comprises: an inlet portion that extends partially along the suction side wall, an outlet portion that extends partially along the pressure side wall, and an intermediate portion that extends between the inlet and outlet portions of the cooling channel, wherein the substrate further defines at least one access channel that extends between and provides fluid communication between a respective hollow, interior space and the inlet portion of the cooling channel, and wherein the access channel intersects a base of the inlet portion of the cooling channel. an inlet portion that extends partially along the suction side wall, an outlet portion that extends partially along the pressure side wall, and an intermediate portion that extends between the inlet and outlet portions of the cooling channel, wherein the substrate further defines at least one access channel that extends between and provides fluid communication between a respective hollow, interior space and the inlet portion of the cooling channel, and wherein the access channel intersects a base of the inlet portion of the cooling channel.