What is the primary purpose of a periapical radiograph?

• A. To detect interproximal caries
• B. To evaluate the tooth apex and surrounding periapical tissues
• C. To visualize soft tissues
• D. To assess occlusion

Answer: (B)

Periapical radiographs image the entire tooth, from crown to root tip, plus the surrounding bone. This makes them ideal for evaluating the tooth apex and the periapical tissues. By focusing on the apex and the adjacent bone, you can detect periapical pathology such as infection or lesions, assess root structure and integrity, monitor healing after endodontic treatment, and identify issues like root resorption. Other purposes, like detecting interproximal caries, are better served by bitewing radiographs; soft-tissue visualization is limited on dental radiographs; and occlusion is assessed primarily through clinical examination, not by periapical imaging.