The dynamic mechanical properties of setting cement concurrently with the exotherm during polymerization to try to relate these two phenomena were investigated. An oscillating rheometric test method, that was able to correlate changes in mechanical properties of setting bone cement with the exothermic polymerization process, was also described. The incomplete polymerization takes place in bone cement where only approximately 75∼85% of monomer converts. It was observed that that the temperature versus time behavior is directly related to how the mechanical properties of the setting cement affect the exotherm. It was shown that the diffusion limitations, or the so-called glass effect limits the setting exotherm in these cements.