Immunological Study On Periodontium Of Dental Fixed Restorations

Artificial crowns are widely applied to clinic. However, periodontal condition is still one of weaknesses after restoration, so it is necessary to focus on the problem and further explore the mechanisms of many reactions between fixed restorations and the periodontal status. At earlier period, the investigations on artificial crown and periodontium were mainly limitted to histology and microbiology. However, immunological study on periodontium of dental fixed restorations is not reported systematically at home and abroad. So this study observed the effect of different prosthesis materials and margin location of restorations on the periodontal tissue with immunologial techniques from the angle of the periodontal response, which was aimed to observe its response, reveal its mechanism and explore the standard of diagnosis and therapy at early stage in order to instruct the clinic operation, reduce the influence caused by bad restorations , lengthen the duration of restorations and promote the periodontal health .The study consist of two sections:1. The clinical study on the effect of different prosthesis materials and margin location of fixed retorations on the secretion of TNF- and IL-6 in GCF.1.1 When the margin of artificial crowns was located in subgingival and gingival crest. Gingival crevicular fluid was obtained by WhatmanI filter paper strips and IL-6 and TNF- a level was detected by ELISA method. After inserting crowns, Both TNF- and IL-6 concetration increased, and the TNF- a level of subgingival group was higher than that of gingival crest group,while the level of IL-6 was of no significant difference between gingival crest and subgingival groups.1.2 Three kinds of crowns on TNF- a : After three kinds of crowns cemented ,on 1th month, there was no marked difference expression of TNF- a among all groups while An obvious difference existed on 6 th month, the secretion of TNF- a in cobalt-chrome crowns increased remarkably compared with gold and PFM crowns, three kinds of crowns had no obvious effect on the release of IL-6 on 1 th month and 6 th month and had no marked difference among their.2. The animal experiment of the effect of different dental alloys and margin location of fixed retorations on the secretion of TNF-a and IL-6 in GCF and the phenotypes of inflammatory cells in surrounding tissues.2.1 Establishment of animal model: Dog were used to establish animal model. IL-6 and TNF- level in gingival crevicular fluid was detected by ELISA method. The results were in accord with that of clinical samples.2.2 Four kinds of crowns on TNF- a : After four kinds of crowns cemented ,on 1th month and 6th month, TNF- a in all groups except gold increased significantly than that in control group; An obvious difference existed only in nicke-chrome between 1th month and 6 th month; the secretion of TNF- a in cobalt-chrome and Nicke-chrome crowns increased remarkably compared with gold crowns,while no obvious difference existed between cobalt-chrome and nicke-chrome, but there was no marked difference between pure tatinium and the others crowns; four kinds of crowns had no obvious effect on the release of IL-6.2.3 Paraffin sections of surrounding tissue of different restorations margin location were stained with fluorescein and observed under Laser Confocal Eletronic Microscope. The results showed that in subginvival group, T-cells(CD3+cells) were the predominant inflammatory cells in the connective tissues surrounding the restorations of subgingival margin , few macrophages (CD14+) were observed, and no B-cells(CD19+) were observed. In ginvival crest group, a small amount of CD3+cells were seen while no CD 14+ and CD 19+ cells were found.2.4 Paraffin sections of tissue surrounding restorations of different prosthesis materials were stained with flurorescein and observed under Laser Confocal Eletronic Microscope. The results sh...