| Porcelain-fused to metal crown (PFM), because of its good appearance, comfort, color fidelity and stability, good functional recovery was widely used in clinic. Ni-Cr alloy PFM because of its cheap is most widely used.But local periodontal condition is still a weakness of PFM crowns concentration.Such as gingivitis and gingival discoloration. As is known these periodontal damages must have been seriously influenced prosthetic effect. The stability of Au-Pt alloy PFM rarely has negative impact on the periodontal tissues. Because of the expensive price, not many patients choose them.The price of gold-plated Ni-Cr alloy PFM as opposed to Au-Pt alloy PFM is low, it is a compromise clinical repair approach. In laboratory, many inflammation mediators and enzymes have been checked up for the past few years. Then the clinical periodontal parameters were recorded for the restored teeth and matched ones. Based on above-mentioned researches we can early detect the effect of PFM crowns on the periodontal tissue, and revealed mechanism of periodontal damages after restorations. So these studies can instruct the clinic operation, lengthen the duration of restorations and promote the periodontal health.Objectives:To investigate the changes of gingival crevicular fluid (GCF) quantity and the concentration of aspartate aminotransferase (AST) and alkaline phosphatase (ALP) in GCF after different alloys based PFM crowns restoration. Relationship between the quantity of GCF,AST,ALP and the health of periodontal tissue was discussed, and the effect of PFM crowns of different materials on local periodontal tissue was explored.Methods:Among 81 patients,90 maxillary incisors with PFM crowns were selected for the study. There are 30 Ni-Cr PFM crowns,30 gold-plated Ni-Cr alloy PFM crowns and 30 Au-Pt PFM crowns. The patients were followed at before preparation the teeth and at 12 months after restoring crowns. Then the clinical periodontal parameters such as plaque index(PLI),sulcus bleeding index(SBI) and probing depth(PD) were recorded for the test teeth. In addition, we collected and weighed the gingival crevicular fluid (GCF) samples of teeth, and analyzed ALP and AST of GCF in laboratory. All data in study were analyzed statistically by SPSS 13.0. 1. Ni-Cr alloy PFM:Compared with preparation of teeth, after cementation Ni-Cr alloy 12 month later only PLI index was insignificantly changed, PD,SBI index,the quantity of GCF,the concentration of GCF-AST and GCF-ALP in GCF increased significantly. Significantly higher than both gold-plated Ni-Cr alloy PFM and Au-Pt PFM group.2. Gold-plated Ni-Cr alloy PFM:The indicators are incremental from the teeth before operation to the teeth after concentration 12 months later. The quantity of GCF the concentration of GCF-AST and GCF-ALP in GCF of gold-plated Ni-Cr alloy PFM were slightly higher than the Au-Pt alloy ones, but significantly lower than that of Ni-Cr alloy ones.3. Au-Pt alloy PFM:Compared with the teeth before operation, the indicators of the teeth after concentration 12 months later were insignificantly different.Conclusions:1. After insertion Ni-Cr and gold-plated Ni-Cr alloy PFM crowns, the majority of results of tested teeth increased more or less than the teeth before operation. And both alloys are disadvantaged to local periodontal tissue. For Au-Pt PFM crowns, the data of the tested teeth and the controlled one changed insignificantly. So this alloy was not adversely to periodontium.2. Gold-plated Ni-Cr alloy PFM crowns are less harmful to periodontal tissue than Ni-Cr PFM. However, gold-plated Ni-Cr alloy PFM crowns are not so good at periodontium as noble alloy (Au-Pt) PFM crowns to a certain extent.3. In this test, the concentration of ALP and AST in GCF can express degree of periodontal disease sensitively, and these indexes can be used in studying clinical periodontal effect after restored PFM crowns. |
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