Effect of Three Kinds of Porcelain Fused to Metal Crowns on the Levels of Aspartate Aminotransferase and Alkaline Phosphatase in Gingival Crevicular Fluid

Objective To further investigate the effects of three kinds of porcelain fused to metal crowns(PFM) on the levels of aspartate aminotransferase(AST) and alkaline phosphatase(ALP) in gingival crevicular fluid(GCF).Methods Selecting 90 patients whose molars ought to accept PFM prosthesis.The patients were randomly divided into three groups.One group was restored with Ni-Cr alloy PFM,the other two groups were restored with Co-Cr alloy PFM and gold alloy PFM individually.At preoperation and on the first week,first month and sixth month after PFM cementation,GCF was obtained by whatman filter paper stips respectively,and the level of AST and ALP were tested.Results The amount of GCF and the level of AST and ALP of three groups teeth were close before restoration(P0.05).After three kinds of PFM cementation,on the first week,all groups increased(P0.05),on the first month,Ni-Cr and Co-Cr were still higher than before and gold group(P0.05),which became the same as before(P0.05).On the sixth month,Co-Cr group also decreased to before level(P0.05),while Ni-Cr group was still higher(P0.05).Conclusion The Co-Cr alloy and gold alloy PFM may affect periodontium less than Ni-Cr alloy PFM in observation period of this study.