Abstract: PURPOSE: To explore treatment regime and curative effect of the casting pure titanium ring on reparation of subgingival residual root. METHODS: Thirty-two teeth were selected for reparation of subgingival residual root after root canal therapy in our department during 2008-2010. The teeth were restored with casting pure titanium ring， glass fiber post and all-ceramic crown. The patients were recalled 12 and 24 months after placement of the pure titanium ring. Gingival crevicular fluid(GCF)samples were collected by filter paper strips . Then the weight of GCF was detected and the gingival index was recorded. The data was analyzed for paired samples t test by SPSS17.0 software package. RESULTS: There was no significant difference in the weight of GCF and the gingival index before and after placement of pure titanium ring (P>0.05). CONCLUSIONS: By using pure titanium ring, most subgingival residual root after root canal therapy can be rehabilitated and function well for long time.

Key words: Subgingival residual root, Pure titanium ring, Fiber post