What are dyes used for in check ups?

• A. To detect caries by staining the demineralised enamel
• B. To whiten teeth
• C. To seal fissures
• D. To kill bacteria

Answer: (A)

Dyes used during check-ups are caries detector dyes. They help reveal areas of demineralised or decayed tooth structure by staining them, so you can see where caries may be present and assess how deep it might be. This supports decisions about whether a restoration or further investigation is needed. They’re not for whitening teeth, sealing fissures, or killing bacteria, which are done by whitening products, sealants, or antiseptics/antibiotics, respectively. Remember that dye results should be considered alongside other checks like visual exam and radiographs, since staining can sometimes occur on plaque or sound areas too.