are applied with additional elastomer to the top and bottom of the assembled annulus nucleus alternately the endplates may be directly molded onto the core outer ring assembly a preset amount of endplate material is placed on the bottom surface of the appropriate mold in a uniform layer the annulus nucleus is placed on top of the endplate material another uniform layer of material is placed on the top and compacted to form the second endplate the male mold is positioned and the pressure and temperature cycles similar to that used for the previous molding steps is performed with the mold temperature raised to the temperature of the melting point of the endplate material the part may be held at an elevated temperature to facilitate bonding lastly a porous layer of either hydroxylapatite or polymeric material can optionally be added to the outer surfaces of the endplates the hydroxylapatite may be attached to the endplates by spreading a uniform layer of hydroxylapatite particles on a heated surface the temperature of the particles is raised to the melt temperature of the endplate material and the flat surface of each endplate is pressed into the heated hydroxylapatite a porous polymeric surface can be achieved by a process of sintering polymeric particulate to the surface or by including particles in.