Restorative care
Cracked a tooth? How the filling-crown-extraction call gets made
A tooth cracks, you are not in much pain, and you are told you need a crown. It is a reasonable moment to be skeptical. Here is the actual reasoning.
A tooth is a structure, not a solid
Think of a molar as a hollow box with walls. It resists chewing force through those intact walls. Remove enough of them (a big cavity, an old oversized filling, a fracture) and the remaining walls flex slightly each time you bite. Flexing propagates cracks. Cracks that reach below the gumline generally end the tooth.
That is why a crown is not “a bigger filling”. A filling fills a hole in the box. A crown replaces the failing outer structure and stops the flexing.
The rough decision line
A filling is enough when: the cavity or chip is small to moderate, there is solid tooth wall on the sides, no crack line runs into a cusp, and the tooth is comfortable on biting.
An onlay or crown is the right call when: most of the chewing surface is gone, a cusp is cracked or already broken off, the tooth aches specifically on release after biting something, or an old wide filling has left thin walls behind. An onlay covers just the damaged cusps and leaves sound walls alone. Where one will do, it is the more conservative choice and the same protection.
A root canal comes into it when: the pulp is inflamed or dying, the crack has reached the nerve, or the tooth is throbbing, keeping you awake, or tender to pressure.
Extraction becomes the honest answer when: the fracture runs vertically below the gumline, so little structure remains that nothing can be anchored, or periodontal bone loss has left the tooth mobile with no support.
Why it can hurt so little
Teeth do not have a pain sensor for structural risk. A crack in enamel and dentine is often silent until it reaches the pulp or a piece breaks off. The classic early symptom is not constant ache but a sharp jolt on releasing a bite, a cracked cusp flexing back. If you have that, mention it specifically; it is one of the most diagnostic things a patient can report.
What to ask when you are told you need a crown
- Can I see the photographs and the X-ray?
- How much sound wall is left, and where is the crack running?
- Would an onlay work instead of a full crown?
- What happens specifically if I wait six months?
- What is the chance this tooth also needs a root canal?
A dentist who can answer those with images in front of you is telling you something checkable. That is what you want.
The part where waiting is expensive
The cost curve on a cracked tooth is steep and it runs one way:
- Cracked cusp, caught early → onlay or crown
- Crack reaches the pulp → root canal plus crown
- Crack runs below the gum → extraction, then an implant or bridge, or a gap
Each step roughly doubles the cost and the number of appointments. Nothing about that is a scare tactic; it is just the sequence.
And if you grind your teeth
Then this article is about you specifically. Sustained nocturnal clenching produces forces well beyond normal chewing, landing on the same few contact points night after night. It is the most common reason cusps crack and crowns fail early, and a custom night guard is a fraction of the cost of one crown.
Written for patients of Oak Hills Dentistry in Spring, Texas. General dental education, not a diagnosis or a treatment plan for any individual. Reviewed by Dr. Neal H. Patel before publishing.
