Factors influencing the creep behavior of poly(methyl methacrylate) cements.

Room temperature compression creep and recovery tests have been performed using samples of pure poly(methyl methacrylate) (PMMA), three commercially available poly(methyl methacrylate) cements, and several experimental cements. From these tests the influence of density, mixing procedure, particle size, methyl methacrylate-styrene copolymer, barium sulfate, aquenous storage environments, residual monomer, molecular weight of the continuous phase, benzoyl peroxide, and N,N-dimethyl-paratoluidine, upon the creep behavior of PMMA cements has been determined. The important results is that lowering the porosity or residual monomer content, increasing the powder size, or adding an MMA-styrene copolymer tends to increase the creep resistance of PMMA cement.