polymethylmethacrylate mass a solvent such as methanol or hot water does not attack the polymethylmethacrylate but effectively diffuses into the polymethylmethacrylate to extract out these unreacted and residual components the removal of these components substantially inhibits discoloration and random chain scission in polymethylmethacrylate upon subsequent irradiation for sterilization purposes application_number US 45537595 A description the method of the present invention is intended for use with prostheses or orthopaedic implants specifically the method of the present invention is designed for use with implants having a polymer layer or coating fixedly adhered to the outer surface of the prosthetic implant in one embodiment the present method relates to implants coated with a pmma coating since conventional bone cement is a mixture of pmma and mma however the method of the present invention is generally applicable to implants having any type of polymer coating or layer thereon a method of applying a pmma coating to an implant is disclosed in u s pat no 4 281 420 and a method of molding a cement layer to an implant is disclosed in pct wo 94 20046 both disclosures are incorporated herein by reference in the formation of pmma small amounts of low molecular components remain after polymerization is complete for example with the molded pmma layer these components include dmpt hq and the monomer mma there also may be trace amounts of peroxide such as benzoyl peroxide the cured pmma molded layer typically contains 0 2 1 0 by weight dmpt 5 30 ppm hq 1 0 4 5 residual mma.