This is a case study on the relationship of decay and cracks. 

Cracks can be difficult to diagnose and find on x-rays.

Decay, take advantage of cracks, as they allow the bacteria to travel out of the mouth and further into the tooth than would normally happen.

The mouth is always changing and the bite never stays the same.

That’s the background, now the case needs to be told, especially the detective work by the non-AI (who shall remain nameless).

The came with pain on biting on the lower left last molar and sensitivity to cold. His next back molar was missing. The opposing upper molar tooth had tilted into the lower space of the missing tooth.

The x-rays did not show any decay or cracks or leaking filling.

The Clues

Using the intra-oral camera we find the upper opposing small second last tooth, has a worn crater (called attrition). 

The amalgam metal filling has a wear crater in the filling (called a bruxofacet).

The upper opposing molar tooth is rotated and its inside peak (called a cusp) is lower down than the other tooth (called a plunger cusp).

The tooth is very tender to tapping on it and cold water running over it.

What do we do?

We need to look underneath the metal filling which is becoming very distorted.

The filling was removed and we found a crack and decay.