Restorative & Materials · single question
A cracked tooth is suspected. When transillumination light is passed through it, what do you MOST LIKELY see?
Show answer and explanation
Correct answer: B. Light illuminates only HALF the tooth (the crack stops light transmission at that point)
- A. Complete darkness suggests either a very opaque material or no light transmission — not specifically indicative of a crack.
- B. Correct. Transillumination is diagnostic for cracks. When light is directed through a cracked tooth, the crack STOPS the light — one side of the crack illuminates and the other side is dark/shadowed. This creates a characteristic 'half-light, half-shadow' appearance, confirming the crack location.
- C. Pink coloration would suggest a pink spot (internal resorption with vascular tissue showing through) — not a crack.
- D. If the entire tooth shines brightly, no crack is blocking the light — this would be a normal finding.
Practice Restorative & Materials questions Restorative & Materials study notes