Which statement about buccal or lingual caries on radiographs is true?

• A. Easily localized with clear border
• B. Always radiolucent
• C. Hard to localize; may overlap pulp
• D. Never associated with cusps

Answer: (C)

Buccal or lingual caries are tough to judge on radiographs because these surfaces lie at the side of the tooth and often run parallel to the film plane. That orientation causes the lesion to be superimposed over other tooth structures, so the radiolucent area can have fuzzy borders and be difficult to localize precisely in three dimensions. The lesion may even project toward or overlap the pulp, which obscures its true extent. That’s why this statement is the best: these lesions are hard to localize on radiographs and may overlap the pulp. In contrast, claims that they are easily localized with clear borders, always radiolucent, or never associated with cusps don’t fit the anatomical and radiographic realities of these lesions.