Which radiographic technique is preferred for caries detection and why?

• A. Panoramic radiographs because they show more anatomy
• B. Bitewing radiographs because PANs distort and miss small lesions
• C. Periapical radiographs for all caries
• D. Digital subtraction radiography is superior but not in list

Answer: (B)

Proximal caries are most reliably detected when you can clearly see the space between adjacent teeth with good resolution. Bitewing radiographs are designed to capture the crowns of the posterior teeth and the interproximal areas in a single image, placing the enamel-dentin junction of adjacent teeth in the same view. This setup makes even early demineralization at the contact points visible, which is why bitewings are the preferred technique for caries detection.

Panoramic radiographs provide a broad view of the jaws, but they sacrifice resolution and have distortions and overlapping structures that can obscure small interproximal lesions. Periapical radiographs show a single or few teeth and are great for evaluating roots and the surrounding bone, but they’re not efficient for screening multiple posterior teeth for proximal caries. Digital subtraction radiography can improve sensitivity by comparing images over time, but it’s a specialized technique not routinely available or used as the standard screening method.