The clinical effect of the two dowel systerms in the restoration of residual root with lowwer ferrule length

Objective To evaluate the effects of the two dowel systerms on clinical assessment in the restoration of residual root with lowwer ferrule length.Methods 86 teeth of residual anterior root were divideded into two groups.Group 1 the cast metal dowels and cores were used.Group 2 quartz-fiber dowel systems were used.All the specimens were restored with porcelain fused metal crown after used two dowel systerms.After 2 years,the success rate and fail type of reparation were analyzed for clinical assessment.Results Over 2-year period,The successful rate(92.8%) of the cast metal dowels and cores was higher than that(84.1%) of the quartz-fiber dowel systems.The failures occurring in cast metal dowels and cores are fractures.The failures occurring in quartz-fiber dowel systems are debonding of posts.Conclusion The cast metal dowels and cores is a good method for the anterior root with lowwer ferrule length.Increasing the retention and abatementing the force are more significant to the clinical performance of restoration.