Expression Of Heat Shock Protein 60 And Heat Shock Protein 70 And Cyclooxygenase-2 In Human Gingival After Ni-Cr Alloy Crowns Prosthetic Restoration

Background: recent years, the general method in clinic restoratory therapy is to make the cast and porcelain fused to metal dental prosthetic restoration. Because of their beautiful outlook, robustness and biocompatibility more and more people adopt them. We make use of Ni-Cr alloy to make bracket, orthodontic wire, porcelain fused to metals crown, cast crown and so on. We have used Ni-Cr alloy for a long time. Its lower price and relative simple cast technology obtain favor of most people. But during the time of using, some problems that we can not anticipate has exposed. The gingiva of patients who has metal restoration become atrophy and black and any other problems. These phenomena influence beautiful outlook and provoke scholars to study, but they can not get according conclusion. Precious metal seldom appears this problem. Some experiments prove that nickel and chrome have hypersensitization and toxicity and carcinogenicity. We can check the hypersensitization of the metals with patch test, but the detection is uncertainty. Besides that it is dangerous to detect the mutagenicity in vitro. But oral cavity is a complex circumstance, we can not ascertain the harm of the oral metal material of Ni-Cr alloy. The pathogenic mechanism is not clear.Aim: By the method of Immunohistochemical streptavidin peroxidase we want to detect the expression of HSP60 (heat shock protein 60), HSP70 (heat shock protein) and COX-2 (cyclooxygenase-2) in human gingiva affected by Ni-Cr alloy and nomal gingiva. We approach the affection of Ni-Cr alloy to human gingiva in molecular level and provide further experimental evidence to the future study.Method: we collect 26 cases that have Ni-Cr alloy prosthetic restoration in oral as the experimental group and distribute them into three portions. Meanwhile we collect thirty normal gingiva as the control group and detect the expression of 60, HSP70 and COX-2 in experimental group and control group by the method of Immunohistochemical streptavidin peroxidase. Then analysis by statistics.Results: Compared with control group, the HSP60 andHSP70 positive rate in the experimental group was significantly increased (P<0.05). Otherwise, Compared with control group, the COX-2 positive rate in the gingiva samples affected for Ni-Cr alloys was obviously variance (P<0.05).Conclusion: We presume that nickel and chrome and any other metals released from Ni-Cr alloy prosthetic restoration may cause inflammation and have carcinogenicity to the gingival tissue.