Which of the following will NOT help in the diagnosis of a cracked tooth?

Correct answer: C. Radiography

• A. Visual examination (especially with magnification and good lighting) IS helpful for detecting cracks — the tooth surface can be directly inspected.
• B. Applying methylene blue dye IS helpful for detecting cracks — the dye penetrates and highlights the crack line. This IS useful.
• C. RADIOGRAPHY typically does NOT help diagnose cracked teeth — cracks are usually vertical and do not have a definable radiolucency visible on a 2D radiograph unless the fracture is in the exact plane of the X-ray beam. This is the EXCEPTION. CBCT is more useful than periapical radiographs but standard radiographs miss most cracks.
• D. Transillumination (shining a light through the tooth) IS helpful for detecting cracks — cracks appear as dark lines that interrupt the light transmission. This IS useful.