Cracked teeth are the masters of disguise. The pain is real but the X-ray looks normal. Diagnosing a cracked tooth requires specialized tools and experience that an endodontist brings — microscope, transillumination, bite tests, and sometimes CBCT 3D imaging.
Patient Education
A short video from the American Association of Endodontists explaining cracked-tooth symptoms, why early treatment matters, and how endodontists often save the tooth.
If any of these sound familiar, schedule an evaluation. Cracks rarely improve on their own and almost always get worse over time.
Especially when biting on something hard or fibrous like nuts, raw vegetables, or seeds. The pain often comes from biting at one specific angle.
A classic cracked-tooth sign. Pain when biting down is common, but pain on release is highly suggestive of a fracture.
Brief cold sensitivity is normal — but if cold sensitivity lingers for 30+ seconds after the cold is removed, that's a sign the pulp is involved.
You may feel the pain but can't tell exactly which tooth it's coming from. Cracks often refer pain to neighboring teeth.
The pain may come and go for weeks or months, making it tempting to ignore. Cracks rarely heal on their own and often worsen.
Cracks are often invisible to the naked eye and don't show up on standard X-rays. Diagnosis requires specialized tools.
Not all cracks are equal. The type and depth determines whether the tooth can be saved — and how urgent treatment is.
Cosmetic only
Tiny surface cracks in the enamel. Very common, harmless, and require no treatment.
Treatable
A piece of the chewing surface breaks off. Usually doesn't reach the pulp. Often restored with a crown.
Endodontic urgency
A crack runs from the chewing surface vertically toward the root. If caught early, can often be saved with a root canal and crown. Treatment delay is risky — the crack can extend.
Often unsavable
A crack has progressed and the tooth is now in two distinct segments. Usually too late for endodontic treatment — extraction often required.
Usually unsavable
The crack starts at the root and progresses upward. Almost always requires extraction. CBCT is critical for diagnosis.
Cracks rarely show on X-rays — that's why patients sometimes go months without a clear answer. Our diagnostic process combines several techniques because no single test is conclusive on its own.
We have you bite on a small plastic instrument placed on each cusp individually. Sharp, brief pain when biting on a specific cusp — and especially on release — strongly suggests a crack at that location.
We apply a brief cold stimulus to the tooth. A normal response is a quick sensation that resolves immediately. Lingering pain (over 30 seconds) suggests pulp inflammation, often associated with a deeper crack.
We shine a bright fiber-optic light through the tooth. A solid tooth lights up uniformly. A crack blocks the light, leaving a dark line that reveals its location.
Under the Zeiss OPMI microscope at up to 25× magnification, cracks invisible to the naked eye become clearly visible. We sometimes apply a drop of methylene blue dye to make hairline cracks even more obvious.
For suspected deeper or root-level fractures, we take a CBCT scan. Unlike standard X-rays, CBCT shows the tooth from every angle and can detect bone changes around a fractured root.
Cracks extend over time. A tooth that could be saved with a root canal and crown today may need to be extracted in three months. Every time you bite down on the tooth, the crack can extend a little further toward the root.
If you suspect a cracked tooth, avoid chewing on that side and schedule an evaluation as soon as possible.
When the crack reaches the pulp but hasn't extended into the root, a root canal removes the inflamed pulp and a crown placed by your dentist holds the tooth together. Success rates are high when treatment is timely.
If the crack is shallow and the pulp is healthy, your dentist may place a crown to prevent further fracture without needing a root canal. We monitor with follow-up visits — sometimes a root canal becomes necessary later.
If the crack has split the tooth or extended below the gum line into the root, extraction is usually the only honest option. We'll explain why and discuss replacement options with your dentist (typically an implant).
Our crack-management approach follows the published outcome literature and the AAE's prognosis framework — not a preference for any restorative product or implant:
No. Unlike a broken bone, dental enamel cannot repair itself. Cracks tend to extend deeper over time as you continue to chew on the tooth.
Standard X-rays look at the tooth from one angle and only show density changes. Most cracks run along the plane the X-ray travels through, making them effectively invisible. Diagnosis requires specialized tools an endodontist uses every day.
Almost always, yes. A cracked tooth needs to be protected by a full-coverage crown from your general dentist. This is typically placed a few weeks after the root canal.
Not always. The earlier you seek evaluation, the better the prognosis. If the crack stays limited to the crown of the tooth, a root canal and crown can save it. If the crack has extended into the root, extraction is often the only option.
The diagnostic visit takes 30–60 minutes. If a root canal is needed, that's usually a separate 60–90 minute appointment, often the same day if you'd prefer.
Based on the research
Microfractures invisible at low magnification become obvious at 16–25×.
Kim & Kratchman, Journal of Endodontics 2006 — foundational review of modern endodontic microsurgery.
The microscope is the diagnostic tool that finally lets us see what's actually happening inside a cracked tooth. A diagnosis made under high magnification is a different kind of diagnosis than one made by eye — and it's the difference between treating the right problem and treating the wrong one.
See the researchDr. Jason Kung provides cracked tooth diagnosis and treatment to patients across Silicon Valley from our Sunnyvale office. Evening and weekend hours, same-day emergencies, free on-site parking.
If you've been told "we can't find anything wrong" but you can feel something is, you deserve a proper diagnosis. Dr. Kung specializes in finding what others miss.
Same-day evaluation available · Mon–Sun
See also: root resection & hemisection — when a vertical root fracture is isolated to one root of a multi-rooted molar, removing just that root can save the rest of the tooth.