Dr. Walter Wright first presented the results of his studies on acrylic resins in July, 1937. The use of resins for adaptation in inlay and crown and bridge prosthesis was first reported in June 1940 by Harris. There has been now and acceptable list of several physical and mechanical properties of acrylic resins which have been studied to a considerable extent by various researchers, or determined from clinical experience. They include; pleasant esthetics, taste, odor, cleanliness, compatibility with oral tissue, dimensional stability, water sorption by imbibition, hardness, ease and success of repair, weight, thermal coefficient of expansion and strength to resist functional stress. The author carried a series of experiments forward to check the strength. Specimens which were cured at boiling temperature showed weaker strength than those ones which were cured at 72℃.