Variation in subgingival flora of abutments before and after removal of nickel-chromium alloy porcelain-fused-to-metal restoration

Guo Da-wei; Song Ling; Zhang Chun-yan; Cao Yang; Li Jing-wen; Liang Xing

doi:10.3969/j.issn.2095-4344.2013.51.009

Abstract：BACKGROUND:Currently, there are few reports on the effect of nickel-chromium (Ni-Cr) al oy porcelain-fused-to-metal (PFM) restoration on subgingival flora of abutment. <br> OBJECTIVE:To investigate the effect of the Ni-Cr al oy PFM restoration on subgingival flora ratio of abutment. <br> METHODS:Nine patients (12 teeth) who suspected that Ni-Cr al oy PFM could affect their health and therefore came to hospital to ask for removal of the prosthesis were selected in this study. Their subgingival plaques of abutment were obtained before and 1 month, 3 months after the Ni-Cr al oy PFM restorations were removed, respectively, and the changes of subgingival flora were observed and analyzed by the method of denaturing gradient gel electrophoresis. <br> RESULTS AND CONCLUSION:The images of denaturing gradient gel electrophoresis in subgingival bacteria of experimental group had significant changes at 1 and 3 months after Ni-Cr al oy PFM restorations removed, furthermore, there were significant differences in the images of denaturing gradient gel electrophoresis at 1 and 3 months. In addition, the specific bands were selected from denaturing gradient gel electrophoresis image that appeared before Ni-Cr al oy PFM restorations removed and weakened or disappeared after the removal of restorations, then 16S rDNA sequence in the specific bands were analyzed. The results showed that the gene sequences of these bands were closest related to Eikenel a corrodens, Campylobacter rectus and Eubacterium saphenu. These findings indicated that the Ni-Cr al oy PFM restorations would result in the changes of the proportion of subgingival microflora and increases in the detection rates of some periodontal pathogens.