This is the last post on the short caries interpretation series and it will be about recurrent caries. When evaluating for recurrent caries look for a diffuse radiolucent area going away from the existing restoration margins typically towards the pulp chamber.
There are a couple of things to be aware of when evaluating for recurrent caries.
- One is a void or liner in the prep. This will be evident as a well-defined radiolucent area adjacent to an existing restoration.
- The second is Mach effect, which is an optical illusion created by the brain when there are two significantly different densities adjacent to each other. This commonly occurs with a metallic restoration and dentin. It will also appear as a well-defined radiolucent line that follows the outline of the restoration. A pseudo-Mach effect can also occur with computer manipulation of a digital image (usually too much edge enhancement used).
Practice radiographs coming later today. If you have any questions or comments, please leave them below. Thanks and enjoy!