Principle?
Light through tooth structure.
← All explanationsTransillumination
What does shining light through a tooth reveal?
Transillumination passes light through tooth structure. Interrupted or altered transmission can reveal areas needing attention, for example during crack assessment. It complements other findings: a shadow alone establishes neither depth nor treatment need.
For training & practice ↓
AI-generated
Choose a view
Position the light
A suitable light source is placed against the tooth. The viewing angle and existing restorations affect the image.
Notice a difference
Some changes transmit light differently. A visible contrast is initially a clue.
Compare with examination
Symptoms, other tests and any indicated imaging also matter. A visible line does not automatically mean a serious fracture.
Read the full explanation
Position the light
A suitable light source is placed against the tooth. The viewing angle and existing restorations affect the image.
Notice a difference
Some changes transmit light differently. A visible contrast is initially a clue.
Compare with examination
Symptoms, other tests and any indicated imaging also matter. A visible line does not automatically mean a serious fracture.
Notes on the teaching images
- Transillumination passes light through a tooth; this image illustrates the optical principle.
- Differences in light transmission can provide clues. The illustrated tooth does not contain a diagnostic finding.
- A shadow alone proves neither decay nor a crack. Examination and, where needed, other methods complement the image.
At a glance
No X-rays?
Correct.
Limit?
Not a complete assessment of depth or cause.
Knowledge in motion
Explained in 36 seconds.
Three steps. No audio.
Each scene can also be selected manually.
Silent educational film with German on-screen text and simplified teaching images. Not a patient case or a promised treatment outcome. The full English explanation is available as text.
Often confused
Shadow and diagnosis
A light contrast is an observation. Professional interpretation determines whether and which change is relevant.
Quick answers
Is this an X-ray?
No. It uses light rather than X-rays. The methods provide different information.
Can it rule out every crack?
No. Location, access and restorations limit assessment. The extent cannot always be determined reliably.
Can I assess this using a phone torch?
No. Household light and a photograph do not provide a reliable diagnosis. New pain or damage needs examination.
At the practice
For a personal discussion
Editorially suggested question to discuss with Dr Niusha Barahmand Pour:
What does transillumination show, and what remains uncertain?
A line in a tooth or pain when chewing? Examination can clarify its significance.
Discuss a tooth findingAppointment selection at DoctolibLearning layer for training & practiceUnderstand terminology and deepen knowledge
- Transmission
- Passage of light through a material.
- Contrast
- A difference in visible brightness.
- Restoration
- For example a filling or crown.
Make the distinction
A light contrast is an observation. Professional interpretation determines whether and which change is relevant.
Sources and context
Editorial research: . General information, not an individual diagnosis or treatment recommendation. Teaching illustrations are simplified and do not depict a patient case.