An Preliminary Experimental Study In The Change Of The Polymerization Characteristics Of PMMA Bone Cement With Different Cooling Methods

Object: To investigate the polymerization time, polymerization temperature, andmechanical properties of polymethylmethacrylate cement with different hypothermiatemperature in Room temperature and37℃to evaluate the feasibility, safety andeffectiveness during percutaneous vertebroplasty(PVP) with the reduction in temperature.Materials and methods: In this experiment, polymethylmethacrylate cement was used,the powder polymers and liquid monomers were mixed with the Proportion2:1. Theexperiments were categorized based on the different types of hypothermic manipulationthat were used. In group A(room temperature, sham group), the temperature were kept at23°C after mixing the bone cement. In group B (precooling the bone cement), the PMMApowder and liquid, as well as the beaker and syringe were stored in the refrigerator (4°C)for24hours before mixing. In group C (ice bath cooling), the blend were immediatelysubmerged in ice water after mixing the bone cement at room temperature. Every groupwas divided into2subgroups, for A1, B1and C1group, the Polymerization was observedin room temperature till the reaction was complete, for A2,B2and C2,the bone cement wasput into37°C incubator when the paste phase came. There were7samples in each group,the polymerization time, polymerization temperature, mechanical properties were observedrespectively. The polymerization time Included the time of liquid phase, paste phase andharden phase. The polymerization temperature Included the highest temperature it reachedand the duration above50°C and60°C. The mechanical properties Included the strengthand stiffness of the bone cement. The completely randomized ANOVA test was used toevaluate the difference between groups and the paired samples test was used to evaluatethe difference between subgroups. The results were considered significant when p-valueswere less than0.05. Results:1.The polymerization time of bone cement with0°C was significantly longer thanthe room temperature group, but the polymerization time of4°C had no statisticaldifference.2.In the37°C body temperature environment, the highest temperature and theduration above50°C and60°C of group C had no statistical difference with the result ofgroup A, however, the highest temperature and the duration above50°C and60°C in groupB was longer than the other groups.3. The mechanical properties of the groups with37°Cbody temperature environment had no statistical difference with the results in roomtemperature.Conclusion: The polymerization time of the bone cement with0°C was extendedsignificantly in room temperature, but was not extended in the37°C body temperatureenvironment, and the polymerization temperature, and mechanical properties were notaffected by the temperature. Because of the above characteristics, put the PMMA bonecement in0°C temperature environment is a feasible, safe and effective measure in PVPsurgery and worth application and promotion.