镍铬合金烤瓷修复体拆除前后患牙龈下菌群的变化

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

背景:目前有关镍铬合金烤瓷修复体对龈下菌群影响的研究还较少。目的:探讨镍铬合金烤瓷修复体对龈下菌群构成比的影响。方法:选择因怀疑镍铬合金烤瓷修复体影响健康而要求拆除原修复体的烤瓷牙患者9例(患牙12颗),于镍铬合金烤瓷烤瓷修复体拆除前、拆除后1个月、拆除后3个月时,采用变性梯度凝胶电泳法检测镍铬合金烤瓷修复体基牙及对侧同名天然牙的龈下菌斑。结果与结论:修复体拆除后1,3个月,患牙龈下菌斑的变性梯度凝胶电泳图谱与拆除前相比均发生了明显变化,而且拆后3个月与拆后1个月相比也发生了较明显变化;此外,选择在修复体拆除前龈下菌斑中经常出现而在拆除后消失或减弱的变性梯度凝胶电泳图像中一些特异性条带作16S rDNA片段的序列分析,结果显示这些特异条带的基因序列分别与啮蚀艾肯菌、直形弯曲菌和隐藏优杆菌有着较高的序列相似度。结果表明镍铬合金烤瓷修复体导致了修复基牙龈下菌群组成的变化,并且导致了部分牙周可疑致病菌构成比增加。

BACKGROUND： Currently, there are few reports on the effect of nickel-chromium （Ni-Cr） alloy porcelain-fused-to-metal （PFM） restoration on subgingival flora of abutment. OBJECTIVE： To investigate the effect of the Ni-Cr alloy PFM restoration on subgingival flora ratio of abutment. METHODS： Nine patients （12 teeth） who suspected that Ni-Cr alloy 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 alloy PFM restorations were removed, respectively, and the changes of subgingival flora were observed and analyzed by the method of denaturing gradient gel electrephoresis. RESULTS AND CONCLUSION： The images of denaturing gradient gel electrephoresis in subgingival bacteria of experimental group had significant changes at 1 and 3 months after Ni-Cr alloy 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 electrephoresis image that appeared before Ni-Cr alloy 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 Eikenella corrodens, Campylobacter rectus and Eubacterium saphenu. These findings indicated that the Ni-Cr alloy PFM restorations would result in the changes of the proportion of subgingival microflora and increases in the detection rates of some periodontal pathogens.