不同修复时间的镍铬合金烤瓷冠龈缘状况及内冠边缘扫描电镜观察

目的：评价不同修复时间的镍铬合金烤瓷冠戴用后的龈缘状况及观察口腔环境戴用后内冠边缘的表面形貌改变。方法：①对修复时间为1～14年的104例镍铬合金烤瓷冠患者144个基牙进行复查,检查冠边缘密合度、牙龈健康及龈缘染色情况;②拆除其中24例患者的冠套,12个拆冠原因为冠色泽欠佳、放射治疗;另12个为冠边缘不密合。用扫描电镜分别对拆除的及新制作的镍铬合金烤瓷冠边缘进行观察比较。结果：不同修复时间的镍铬合金烤瓷冠龈缘状况比较差异无统计学意义（P〉0.05）。电镜下戴用后的镍铬合金烤瓷内冠边缘均观察到腐蚀迹象,以冠边缘不密合尤甚。结论：镍铬合金烤瓷冠在口腔中存在腐蚀,但与修复时间无明显相关性,腐蚀程度与修复体的冠边缘密合度有关,同时会影响到龈缘的状况。

GINGIVAL MARGIN CONDITION EVALUATION AND SCANNING ELECTRON MICROSCOPIC OBSERVATION OF THE INTERNAL CROWN MARGIN FOR THE NI-CR ALLOY-PORCELAIN CROWNS WITH VARIOUS SPAN

Objective：To evaluate the gingival margin condition around the crowns and observe the surface topography of the internal crown fringe in cases that have Ni-Cr alloy-porcelain crowns manufactured for various span.Methods：One hundred and Four patients with 144 Ni-Cr alloy-porcelain crowns for 1-14 years＇ were asked for return visiting,to examine the fitness of the crown margin,the health condition and the color of the gingival.The crowns of 24 patients were removed for color difference and radioactive therapy（12 patients）and unfitness of the crown margin（12 patients）.The margin of the crown removed was examined with the scanning electron microscopic,which was compared to the crowns newly made.Results：There was no statistic significance in gingival margin condition around the Ni-Cr alloy-porcelain crowns in various span（P〉0.05）.Crown margin corrosion was observed in all cases and especially obvious for the unfit crown margin.Conclusion：Corrosion of the Ni-Cr alloy-porcelain crowns exists in the oral cavity and has no relationship with the time repaired.The extent of the corrosion,which may affect the gingival condition,is related to the fitness of the crown margin.