A few weeks ago, a patient walked into our Torrance office looking frustrated. She told me she’d been to two other dentists already. Both said her teeth “looked fine.” But every time she bit down on something chewy — a piece of bread, even — she’d feel this sharp zing that shot through her lower jaw. It was quick. Like a lightning bolt. And then it would just… disappear.
She thought she was imagining it. Her husband thought so too.
She wasn’t imagining it. She had a cracked tooth.
This happens more than you’d think. Cracked teeth are one of the trickiest problems in dentistry. And if you’re reading this because you’ve got some weird pain that nobody can figure out, you might be dealing with one too.
That “Zing” When You Bite Down — What’s Going On?
Here’s the deal with cracked teeth. The crack itself is often so tiny you can’t see it. Your dentist can’t see it. It doesn’t show up on a regular X-ray. But every time you bite down, the two pieces of the tooth flex apart just a little bit. That movement irritates the nerve inside.
And that’s when you get the zing.
The weird part? The pain usually happens when you release the bite, not when you clamp down. So you bite into a piece of almond, it feels fine. You open your mouth, and — there it is. That sharp jolt.
Then it’s gone. And you think, “Maybe it was nothing.”
It’s not nothing.
Not All Cracks Are the Same
This is where it gets a little tricky. There are actually five different types of tooth cracks, and they range from “no big deal” to “we have a real problem.”
Craze Lines
These are the tiny surface cracks you see on almost everyone’s teeth. Look closely at your front teeth in the mirror — you’ll probably spot some. They’re just in the outer enamel. They don’t hurt. They don’t need treatment. Totally normal.
Fractured Cusp
This is when a piece of the chewing surface breaks off. It usually happens around a large filling. The good news? The crack typically doesn’t reach the nerve. It hurts, but it’s usually a straightforward fix. Your dentist can put a crown on it and you’re good.
Cracked Tooth
This is the one that drives people (and dentists) crazy. The crack starts at the chewing surface and runs down toward the root. Sometimes it reaches the nerve. Sometimes it doesn’t — yet. The symptoms come and go. Some days it hurts, some days it doesn’t. It can go on for months before someone figures out what’s happening.
This is the type that patient in my Torrance office had.
Split Tooth
A split tooth is basically a cracked tooth that nobody caught in time. The crack has gone all the way through, and the tooth is now in two separate pieces. At this point, saving the whole tooth usually isn’t possible. Sometimes I can save a portion of it, but often it has to come out.
Vertical Root Fracture
This one starts at the root and works its way up. It’s sneaky because it can cause a low-grade infection that mimics other problems. These fractures often happen in teeth that have already had root canal treatment. They’re tough to catch, and unfortunately, most of the time the tooth needs to be extracted.
Note: The sooner a crack is found, the more options you have. A cracked tooth that’s caught early can often be saved with a crown or root canal. Wait too long, and that same tooth might need to come out.
The Symptoms That Should Get Your Attention
Cracked tooth pain doesn’t act like other tooth pain. It’s unpredictable. Here’s what to watch for:
- Sharp pain when biting — especially when you bite on something hard or chewy, and especially when you release the bite
- Sensitivity to hot and cold — but not the kind that lingers for minutes. More like a quick flash of pain when you sip hot coffee or eat ice cream
- Pain that comes and goes — this is the big one. It’s not constant. You might go days without any discomfort, then it hits you out of nowhere
- Pain that’s hard to pinpoint — you know something hurts, but you can’t tell your dentist exactly which tooth it is. The pain might feel like it’s moving around
If you’ve got pain like this — the kind that makes you second-guess yourself — a cracked tooth should be on the list of possibilities.
Why the Pain Disappears
People ask me this all the time. “If my tooth is cracked, why doesn’t it hurt all the time?”
Because the crack doesn’t flex every time you chew. It depends on which direction the force is coming from and what you’re eating. You can sit in the dental chair, bite down on a test stick, and feel nothing. Then you go home, eat dinner, and there it is again.
Why Cracks Are So Hard to Find
Cracked teeth are one of the hardest things to diagnose in dentistry. I’ve been doing this for years, and they still keep me on my toes. Here’s why:
Regular X-rays don’t show most cracks. X-rays are great for cavities and infections. But a crack runs vertically, and X-rays shoot through the tooth horizontally. The crack just doesn’t show up. Your dentist isn’t missing anything — the technology has a blind spot.
The symptoms mimic other problems. A cracked tooth can feel like a cavity, a sinus issue, or even TMJ pain. I’ve seen patients who were treated for the wrong thing because the crack wasn’t on anyone’s radar.
You can’t always reproduce the pain in the office. The crack might only hurt when you bite on a specific food, at a specific angle. Try to recreate that with a dental instrument and it doesn’t always work.
So how do we actually find these cracks? That’s where specialist tools make a difference.
How I Track Down Cracks Other Dentists Miss
At our office here in Torrance, I use two things that most general dental offices don’t have: a CBCT scanner and a dental operating microscope.
CBCT 3D Imaging
A CBCT scan is like a CT scan but designed specifically for teeth and jaws. Instead of a flat 2D image, I get a full 3D view of the tooth from every angle. I can rotate it, slice through it, and see root structure in detail. It doesn’t catch every crack, but it shows way more than a standard X-ray.
The Dental Microscope
This is the game-changer. I work under a microscope that magnifies everything up to 25x. At that magnification, I can see crack lines that are invisible to the naked eye — how deep they go, whether they reach the nerve, and whether the tooth can be saved.
That patient I mentioned at the start? Two dentists looked at her tooth and saw nothing wrong. Under the microscope, I could see a hairline crack running right down the middle of her molar.
Bite Tests and Transillumination
I also use some lower-tech methods. A bite stick test — where you bite down on a small plastic device, one cusp at a time — can isolate which part of the tooth is cracked. And shining a bright light through the tooth (transillumination) reveals crack lines that scatter the light.
When a Cracked Tooth Needs a Root Canal
Not every cracked tooth needs a root canal. If the crack is only in the enamel or the outer layer of the tooth, a crown might be all you need. The crown holds everything together and stops the crack from spreading.
But if the crack has reached the pulp — the soft tissue inside the tooth where the nerve lives — then the nerve is going to get inflamed and infected. At that point, a root canal is the way to save the tooth. We remove the damaged nerve, clean out the inside, seal it up, and then your dentist places a crown on top.
Here’s my honest take: if you’re having symptoms, don’t wait. A crack only gets worse with time. A tooth I could save today with a crown might need a root canal next month. And the tooth I could save with a root canal today might be unsaveable six months from now.
Note: After root canal treatment on a cracked tooth, getting a crown quickly is really, really important. The crown is what holds the cracked tooth together. Without it, the crack can keep spreading and you could lose the tooth even after successful root canal treatment.
When a Cracked Tooth Can’t Be Saved
I wish I could save every tooth. I can’t.
If the crack extends below the bone line — deep into the root — extraction is usually the only option. Same goes for a tooth that’s fully split in two. I always tell patients the truth. If a tooth can be saved, I’ll save it. If it can’t, I’ll tell you straight and help you figure out the next step.
What to Do If You Think You Have a Cracked Tooth
If you’re in the Torrance or South Bay area and you’ve got that weird, unpredictable tooth pain that nobody can explain — come see us. Cracked teeth are literally what I deal with every day.
Here’s what your first visit looks like:
- We’ll talk about your symptoms — when the pain started, what makes it worse, what makes it better
- I’ll take a CBCT 3D scan to get a detailed look at the tooth
- I’ll examine the tooth under the microscope
- We’ll do some bite tests to isolate the problem
- I’ll tell you exactly what I find and walk you through your options
No guessing. No “let’s wait and see.” You’ll leave knowing what’s going on.
Call (310) 378-8342 to schedule a consultation at our Torrance office. If you’re in pain, we offer same-day emergency appointments — because a cracked tooth doesn’t wait for a convenient time.