抄録
The close association between restorations with ill-fitting margin (especially overhanging margin) and periodontal disease has been accepted as a common opinion by the dental profession. The purpose of this study was to survey the subgingival microflora in patients treated with fixed prosthetic appliance. Subjects were divided into three groups (H group: periodontal health, G group: gingivitis, P group: periodontitis) by the clinical parameters of the periodontal tissue. The results indicated the changes of the subgingival microflora in every group, that is, G group had a significantly higher level of genus Actinomyces (0.05≥P>0.01) and a lower level of genus Streptococcus (0.01≥P>0.001), whereas P group had a significantly higher level of genus Bacteroides (P≤0.001) and a lower level of genus Streptococcus (P≤0.001) than H group. The present study suggests that overhanging margin is one of the factors causing the microbial succession in subgingival microflora. This fact should be noted as iatrogenic factor in the prosthetic treatment by the dental profession.
