LETTERS FROM THE STUDIO LETTER NO. 27

The cracked tooth: crown, root canal, or goodbye? How we decide.

Endodontist examining cracked tooth under microscope to determine treatment
UNDER THE MICROSCOPE — TRACING THE CRACK

You've been told your tooth is cracked. Now comes the harder question: what do you do about it? The answer depends entirely on what kind of crack you have, how deep it goes, and whether the nerve is involved. A crack one patient needs a simple crown for might mean a root canal in another — or extraction in a third. I evaluate cracked teeth every day. Here's the decision framework I actually use.

Five cracks, five verdicts.

PLATE 1 — CRAZE LINES

The harmless ones.

VERDICT: NO TREATMENT

Tiny superficial cracks in the outer enamel only — look closely at any adult's front teeth and you'll find them. No symptoms, no problem, no treatment. If a dentist mentions them, don't worry.

SYMPTOMS: NONECOST: $0
PLATE 2 — FRACTURED CUSP

The clean break.

VERDICT: CROWN ONLY

A piece of the chewing surface breaks off, usually around a large filling — a clear "something broke" moment. The crack doesn't reach the nerve, so a crown holds the tooth together and no root canal is needed.

PROGNOSIS: EXCELLENTCOST: $1,200–1,800 (CROWN, AT YOUR DENTIST)
PLATE 3 — CRACKED TOOTH

The tricky one.

VERDICT: DEPENDS ON DEPTH — CROWN, OR ROOT CANAL + CROWN

The most common type I see: a crack starting at the chewing surface, extending toward the root. The classic "lightning bolt" zing when biting — especially on release. Depth decides everything: if the microscope confirms the crack stays above the nerve, a crown stops it. Once it reaches the pulp, the nerve is compromised — root canal first, then the crown.

Timing matters. A crack that needs only a crown today might need a root canal next month — and a saveable tooth can become unsaveable. Don't sit on a symptomatic cracked tooth.

PROGNOSIS: GOOD–EXCELLENT IF CAUGHT EARLYCOST: $1,200–1,800 OR $2,100–3,500
PLATE 4 — SPLIT TOOTH

The preventable ending.

VERDICT: USUALLY EXTRACTION — RARELY A PARTIAL SAVE

An untreated crack that propagated all the way through, splitting the tooth in two. If only one root of a molar is involved, a hemisection can sometimes save the rest. More often, extraction and replacement. This is what happens when a cracked tooth waits too long.

PROGNOSIS: POORCOST: $4,000–6,000+ WITH IMPLANT
PLATE 5 — VERTICAL ROOT FRACTURE

The one we can't save.

VERDICT: EXTRACTION

A crack starting in the root and working upward — sneaky, often appearing years after a root canal, mimicking failed treatment or gum disease. It can't be repaired; the crack is a permanent highway for bacteria. The good news: CBCT and the microscope can diagnose it definitively before you commit to any treatment path.

PROGNOSIS: NOT SAVEABLECOST: EXTRACTION $200–600 + IMPLANT $4,000–6,000+

The decision ledger, at a glance.

CRACK TYPETREATMENTROOT CANAL?PROGNOSIS
Craze linesNoneNo
Fractured cuspCrownNoExcellent
Cracked tooth (shallow)CrownNoVery good
Cracked tooth (deep)Root canal + crownYesGood
Split toothExtraction (rare hemisection)SometimesPoor
Vertical root fractureExtractionNoNot saveable

Why diagnosis is everything.

You can’t choose the treatment without knowing the crack’s depth — and you can’t know the depth without the right tools. Surface lighting shows the crack but not where it ends; standard X-rays miss most cracks entirely. Guess wrong and you either overtreat (a root canal that a crown could have prevented) or undertreat (a crown over a crack that’s already reached the nerve).

Three tools settle it: CBCT 3D imaging reveals root fractures and the bone-loss patterns that trace a crack’s path. The surgical microscope lets me follow the crack line directly and see exactly where it stops — the single most important tool for this diagnosis. Bite testing isolates the involved cusp, reproducing your symptom on demand.

"Without a microscope and CBCT, you're guessing at the treatment — and guessing wrong costs a tooth."

Not sure your tooth is even cracked?

Cracked-tooth pain is distinctive but confusing — it comes and goes, and it’s hard to point to. These are the tells:

  • Sharp pain when releasing a bite, more than biting down
  • A brief flash of temperature sensitivity — not lingering ache
  • Pain on one side only, in one position
  • Symptoms that crept in gradually and keep slowly worsening
  • A large existing filling in the suspect tooth
THE BOTTOM LINE

Not all cracked teeth need the same treatment — the verdict lives in the crack's depth and direction, and only a microscope and 3D imaging can read it. The earlier the evaluation, the more conservative (and less expensive) your options.

Every cracked-tooth evaluation here includes both. You leave knowing exactly what the crack looks like — and what it needs.

MEDICAL DISCLAIMER: FOR INFORMATIONAL PURPOSES ONLY — NOT MEDICAL ADVICE. CONSULT A QUALIFIED PROFESSIONAL FOR DIAGNOSIS AND TREATMENT.

That zing when you bite? Worth a look.

Every cracked-tooth evaluation includes CBCT and microscope examination.