What does it indicate when a probe penetrates between a tooth and amalgam?

When a probe penetrates between a tooth and amalgam, it sometimes indicates the presence of caries. This scenario often occurs in the context of inadequate sealing between the tooth structure and the restorative material. Factors such as marginal gaps, incomplete margins, or wear can create pathways for bacteria to enter, leading to decay.

While this situation can suggest caries, it is important to recognize that penetration could also result from other issues, such as a normal assessment in a well-fitted restoration or probing technique. Thus, the assessment should be comprehensive, evaluating the overall health of the tooth and restoration before concluding that caries is present. The likelihood of caries is significant but not definitive, as other factors could lead to similar probing results.