Studies on the Fatigue Properties of Dental Plastics Materials

Abstract

Dental plastic materials (most of them are polymethyl-methacrylate polymer) are commonly used for partial and full denture as prosthetic appliance. For the basic design of raising efficiency of these materials it is important to promote their experimental knowledge as to their fatigue strength which has not hitherto been sufficiently developed.So in this paper a report is made on the fatigue strength of these materials, the relation between the surface roughness and strength and the influence of the polymerization method employed on these materials.As the result of the experimental studies the following conclusions are made.There has been remarkable influence of the polymerization method on these materials which were finished with the emery paper, number 04. The wet heat polymerization is superior to the dry heating on the static and fatigue strength. The degeneration of fatigue strength of the dry heat polymerization is greater than the static properties and the surface roughness influences for fatigue strength.The influence of the finishing methods on the surface roughness is not seen in the results of the surface inspection but in their fatigue strength.In the comparative study of the dental materials with the engineering materials, the S-N curves of the dental materials show their continuous behavior, and their difference from polymethyl-methacrylate (PMMA) of the engineering materlais. And the degeneration of fatigue strength of dental PMMA materials is less than that of their static strength.