The retentive and stress-distributing properties of a threaded endodontic dowel.

When the Radix Anchor apex was allowed to engage the bottom of the prepared channel, very high apical stresses were generated within the supporting structure. When the coronal flanges engaged the occlusal portion of the model, high lateral stresses occurred in the coronal portion of the channel. These stress concentrations can be avoided by installing the dowel so that only the retentive threads engage dentin. This may be accomplished by "backing off" one half turn when slight resistance to dowel threading is encountered. The Radix endodontic dowel system was more retentive than cemented dowels and less retentive than another dowel which threads into the dentin of the channel wall. The Radix Anchor was more retentive when both diameter and length of imbedment were increased simultaneously.