不同含量有机蒙脱土增强义齿基托树脂强度对MMA含量的影响

Measurement and analysis of residual MMA monomer concentration in OMMT reinforced denture base polymers

目的研究不同含量的有机蒙脱土(OMMT)增强义齿基托树脂强度对基托中残留甲基丙烯酸甲酯(MMA)含量的影响,以确定最佳的OMMT掺入量。方法将OMMT与PMMA按比例0%、1%、3%、5%(wt%)混合,然后滴入50ml MMA,粉液比为2g/1ml。待调和的材料进入面团期时充入直径50mm,厚3.0±0.1mm的不锈钢模具中,于水浴中加热固化,冷却后取出试样,用丙酮抽提其中残留的MMA,用氯仿萃取其在水中释放的MMA,气相色谱法测定抽提液和萃取液中MMA的浓度。结果 OMMT的量对义齿基托树脂中残留MMA的量有显著性影响(P<0.05),随着固化材料中OMMT的量的增加,残留MMA的量也逐渐增加。当OMMT的混合比例为2wt%时,不仅材料的机械性能的到了较好提升,材料中的残留MMA的量也在YY 0270-2003标准(最大2.2wt%)范围内。放置于37℃水中7d后,MMA的释放量随时间的增加趋于稳定;观察14d,MMA水中释放量小于用丙酮抽提时所测得的残留MMA量。结论固化材料中MMA的含量随着OMMT含量的增加而增加。材料在水中的MMA释放量小于用丙酮抽提时所测得的MMA量。

Objective This study aims to detect the effect of different content of organic montmorillonite（OMMT） on residual methyl methacrylate（MMA） of denture base resin,when OMMT was used to reinforce the mechanical strength.Methods PMMA was mixed with different content of OMMT,and 50ml MMA was added in the mixture.Stay mixed materials into the dough period,when filling diameter 50 plus or minus 0.1mm thick 3.0 stainless steel moulds,and put it into water bath until it become solidify,then take the sample after cooling.Acetone and chloroform were used to extracted the residual MMA monomer of resin and residual MMA monomer released from resin in water.Gas chromatography（GC） was used to determine the concentrations of MMA monomer.Results OMMT gave a significant increase of residual MMA monomer concentration（P0.05）.As the content of the OMMT increased,the amount of residual MMA monomer in the polymers increased.If the mixed proportion of OMMT was 2wt%,the amount of residual MMA monomer in the cured polymers complied with the national standards（2.2wt%） and the mechanical properties of the resins were better improved.After 7 days in water,the amount of MMA released from the polymers tended to stable.Observed 14 days in water,MMA monomer was found less in water than that extracted with acetone.Conclusion The current study suggested that the concentration of residual MMA monomer increased as the content of the OMMT increased in the polymers.The residual MMA monomer released in water was found less than that extracted with acetone.