Final answer:
Periapical radiographs are used to assess bone levels and root structures, while bitewing radiographs are primarily used for detecting interproximal caries.
Step-by-step explanation:
Periapical radiographs are used to assess bone levels and root structures, which can help in diagnosing periapical pathology. These X-rays focus on capturing a broad view of the entire dentition, including the crowns and clinical crowns of teeth, as well as the surrounding bone structures. On the other hand, bitewing radiographs provide a comprehensive view of the interproximal areas between teeth, making them specifically useful for detecting interproximal caries.