镍铬合金烤瓷全冠腐蚀性分析

Corrosion Test of Nickel-chromium Porcelain-fused-to-metal Crown from Samples of Two Denture Factories

对不同两地加工厂生产的镍铬合金烤瓷熔附金属全冠(porcelain-fused-to-metalcrown,PFM冠)进行了为期一年的体外腐蚀性对比研究,分析该产品应用近30年来烤瓷全冠中镍的析出量及其市场的规范化程度。将两厂家生产的镍铬PFM冠样品共40个,随机分为4组(10天组、1月组、6月组、12月组),分别浸泡于ISO/TR10271标准(37℃,pH6.8)配制的人工唾液中,于10天、1月、6月、12月用电感耦合等离子体发射光谱仪(ICP-AES)测定浸提液中析出的镍离子浓度,同步采用X射线能量散谱仪(EDS)、正置式金相显微镜分析、观察样品元素构成及金相显微组织结构。结果显示两厂样品的镍离子析出量在一年组差异具有统计学意义(F=9.360,P=0.000)。能谱分析显示两厂样品主要成分都为Ni、Cr、Mo,但含量不同;其金相结构均为树枝状共晶结构,但B厂样品较A厂夹杂物多,枝晶粗、排列紊乱、晶间相多。一年内两厂的镍铬合金烤瓷冠在抗腐蚀性能方面存在差异性,远期效果有待进一步观察。

A corrosion test in vitro was taken on the Ni-Cr PFM（porcelain-fused-to-metal,PFM） crown specimens from two different denture factories during one year by means of inductively coupled plasma atomic emission spectrometry （ICP-AES）, in order to analyze Ni release in it and understand the degree of local market normalization. Four groups of the Ni-Cr PFM crown samples from two factories were soaked in the ISO/TR10271 standard artificial saliva （37℃, pH 6. 8 ） and were examined the content of the nickel ion released using ICP-AES method in ten days, one month, six months and twelve months. The composition and the microstructure of samples were analyzed and observed by X-ray energy dispersive spectrometer （EDS） and metallographic microscope simultaneously. Nickel ion released content was different between two factories in one-year group （ F = 9. 360,P = 0. 000）. The EDS analysis appears that the composition of samples is mainly Ni, Cr, Mo, but the content was different, metallographic structure of Ni-Cr ceramic alloys were dendritic eutectic structure, but the B factory sample compares the A factory the size of dendritic crystal grain coarsening, shrinkage cavity, porosity and inclusion gradually increased. The corrosion resistance of the Ni-Cr PFM crown samples from two factories was different,but the longtime effect needs to be further studied.