Investigation of hydrostatic pressure changes during cementation of screw-retained posts, and posts with integral...

Intra-radicular pressures during the cementation of screw-retained posts have been found to reach 1.5 x 10(4) KN/m2 when cement is inserted into the prepared post hole or no pressure, indicating that an incomplete cement lute had developed, when the post was coated with cement. The effectiveness of cement channels was investigated and for the traditional single channel, using the cement 'insertion' method, there was an intra-radicular pressure of 8.5 x 10(4) KN/m2, compared with 1.1 x 10(4) KN/m2 for the corresponding round post. Multiple cement release channels gave an enhanced pressure reduction to 2.0 x 10(3) KN/m2.