An investigation of the process of casting cores on to preformed wrought dental posts.

The casting of gold on to wrought "Wiptam" and "G.T." posts has been investigated. Notching of "Wiptam" posts gave rise to grain structure rearrangement; carbon deposits from the wax burn were retained in the notches and prevented complete filling by the gold. Serious cracks developed from these notches when the core was cast on centrifugally but only slightly when Solbrig's method was used. These cracks explain why "Wiptam" posts occasionally fracture. The above problems were not encountered with the "G.T." post, which has inbuilt retention channels, and allows a more complete burn out of the wax pattern.