Recurrent caries detection can be affected by which factor?

• A. On the incisal edge
• B. On the apex of tooth
• C. Next to a restoration; faulty angulation may cause misdiagnosis
• D. On the root surface away from restorations

Answer: (C)

Recurrent caries are those that occur at the margin of a tooth-restoration or beneath a defective restoration. Detecting them relies on accurately assessing the tooth-restoration interface and how the area appears clinically and on radiographs. If a restoration is placed with faulty margins or overhangs, plaque and bacteria can accumulate at the interface, and microleakage can hide or mimic decay, making it harder to tell where decay starts. Radiographic detection is also highly sensitive to angulation: an improper angle can make a lesion near a restoration look deeper, shallower, or even disappear behind the restoration material, leading to missed or misdiagnosed decay. Choices that involve other tooth regions don’t capture the scenario of decay at or near a restoration, so the factor described—being next to a restoration with faulty angulation causing misdiagnosis—best explains why detection can be affected.