Changes Of Periodontal Condition And Expressions Of HLA-DR And Survivin In Gingival Tissue After Dental Ni-Cr Alloy Prosthetic Restoration

Background and objective:Favourable physical function, mechanical function, chemicel function and more significant biological security, biocompatibility, biological functionality all be very consequent specification in clinical application of dental prosthesis materials. Porcelain fused to metals(PFM) possess metallic strength and porcelaneous aesthetics. PFM could be utillized to recuperate odontal appearance and function. Because they have high fidelity colouration, smooth glossy surface and better abradability and anti-impulsing. They belong to lifetime dental prosthesis materials. Non-precious metals such as nickel-chromium alloys(Ni-Cr alloys) are widely uesd in clinical prosthodontic treatment nowadays. However, in some patients the mental ions which are released from Ni-Cr alloys may cause the oral parenchyma allergy and diverse clinical symptom such as gingival hyperplasia, red swelling of the gingiva, gingival pigmentation and so on. Despite intensive research, its detailed mechanism and pathgenesy of the sensibilization remain unknown. Some studies indicate the powder dust containing nickel or chromium is able to result in rhinocarcinoma, upper respiratory cancer and bronchogenic carcinoma. But there is no report that Ni-Cr alloys may cause canceration of the oral tissue. This experiment is to detect the expressions of HLA-DR and Survivin in gingival tissue and to research the sensibilization and carcinogenicity of Ni-Cr alloys.Methods:Patients who accepted half Ni-Cr alloy crowns or fixed bridges were selected. One year later the crowns or fixed bridges were observed through detecting the periodontal condition, and recording the sulcusbleeding index, plaque index and periodontal depth. Immunohistochemical streptavidin peroxidase method was used to detect the expression of HLA-DR, Survivin in the gingiva samples affected for Ni-Cr alloys and normal gingiva tissue samples.Results:â‘ The rate of gingiva discoloration after Ni-Cr alloy crowns/fixed bridges prosthesis was 6.98%, and had no direct relationship with patients'gender, age, prosthetic category(Pï¹¥0.05). Compared with control teeth group, plaque index of Ni-Cr alloys group was not obviously variance(P>0.05), but sulcus bleeding index and periodontal depth were significantiy increased (P<0.05).â‘¡Compared with normal gingiva tissue, the HLA-DR positive rate in the gingiva samples affected for Ni-Cr alloys was significantly increased (P<0.05). But HLA-DR positive expression had no direct relationship with patients'gender, age, prosthetic category (Pï¹¥0.05). Otherwise, Compared with normal gingiva tissue, the Survivin positive rate in the gingiva samples affected for Ni-Cr alloys was not obviously variance ( P<0.05).Conclusion: Ni-Cr alloys have no obvious influence on dental plaque foemation, but the adverse effect of Ni-Cr alloys on periodontal tissue is objectively existing, that could induce gingivitis. HLA-DR positive rate in the gingiva samples affected for Ni-Cr alloys was significantly increased. This indicates that mental ions released from Ni-Cr alloys may have hypersensitization to the gingiva tissue being in activated inflamm state. There was no the positive expression of Survivin in the gingiva samples affected for Ni-Cr alloys. And this indicates that Ni-Cr alloys have no carcinogenicity or potential carcinogenicity to the gingiva tissue.