Improving the seal of amalgam cores with cemented dowels: A comparative invitro radioactive tracer study

Amalgam cores with cemented dowels are commonly used to restore endodontica lly treated teeth. These restorations were widely studied for their mechani cal properties; however, less is known about their sealing ability. The eff ect of the cement type used for the dowel and that of a bonding agent appli cation were studied in a radioactive tracer coronal leakage study. The seal ing ability of posts and cores was also compared with that of 5 mm remainin g root canal fillings, Composite luting cement provided a better seal than zinc phosphate cement. The seal provided by 5 mm root canal fillings was po orer than that provided by posts and cores. High variability in seal qualit y was found among all types of posts and cores studied. This may indicate t hat the seal provided by cemented dowels with amalgam cores is unpredictabl e. Because neither the remaining root canal filling nor the post and core m ay be trusted alone for a seal, each should be performed with the greatest care and both covered with a crown as soon as possible.