The Post and Core Rocks in the Tooth and Is Unstable: What Should We Do?

The post and core rocks in the tooth and is unstable. What should we do?

When a post and core is unstable on the tooth, one of the first things I think of is a sharp point, either on the tooth or on the post and core itself, that prevents the post from seating fully.

For example, a part of the tooth may have been sharp when I used Duralay to make the post and core over it. Initially, it fitted snugly and was stable, but after casting, that same sharp point prevented complete seating. Or the tip of the post may have been very sharp, and after it was converted into metal, a nodule or defect formed on it and prevented it from seating.

That is why, in this situation, I first go back and check the sharp area and adjust it if necessary. This often solves the problem, but it did not in this case.

So I remade the post and core from scratch. You cannot place a crown over it with this lack of stability. Once the crown enters the chewing cycle and is subjected to chewing forces, if we do not have stability, those forces are transferred to the cement–post interface, creating shear forces, and eventually the crown comes out of the tooth together with the post.