Why Dental Crowns Fall Off (and How We Make Them Stay)
If you've had a crown come loose more than once, you already know the frustration—and you've probably heard "we'll just re-cement it" one too many times. Here's what most people don't realize: when a crown keeps falling off, it's rarely about bad luck or weak cement. In our years working with patients across Kansas City, Kansas, we've learned that lasting crown retention comes down to three clinical factors that need to work together: the shape of your prepared tooth, the environment during bonding, and the forces your bite puts on that crown every single day.
Let's walk through what actually makes crowns stay—and what we do differently when they don't.
The Foundation: Why Tooth Preparation Matters
Think of a crown like a cap on a fence post. If the post is too short, too smooth, or flares outward at the top, that cap isn't staying put no matter how much glue you use. The same principle applies to dental crowns.
When a tooth doesn't have enough height or has walls that taper too steeply (or not at all), there's simply not enough surface area for the crown to grip. This is called inadequate retention form, and it's one of the most common reasons crowns fail—especially on teeth that have been heavily restored before.
What we do about it:
Core build-ups restore tooth structure when decay or fractures have left too little to work with
Crown lengthening gently reshapes gum and bone to expose more tooth, giving the crown a proper foundation
Prep refinement adjusts the taper and shape to create better mechanical resistance
Every case is different, but the goal is always the same: give the crown something solid to hold onto.
The Chemistry: Getting the Bond Right
Even a perfectly shaped tooth won't hold a crown if contamination gets in the way. Saliva, blood, or even moisture from your breath can prevent dental cement from bonding properly—and once that microscopic gap forms, bacteria and fluids seep in, weakening the seal over time.
This is where technique matters as much as materials. A dentist in Kansas City, Kansas who takes time to isolate the tooth, select the right cement for your specific case, and follow the manufacturer's protocol isn't being overly cautious—they're building durability into the restoration from the start.
Our approach includes:
Isolation protocols like rubber dams or careful retraction to keep the area completely dry
Cement selection matched to the crown material and clinical situation (not all cements work the same way)
Proper curing and set time—rushing this step is a common but avoidable mistake
The right cement, applied in the right conditions, can make the difference between a crown that lasts two months and one that lasts twenty years.
The Forces: Your Bite Is Stronger Than You Think
You generate hundreds of pounds of force when you chew—and if a crown sits even slightly high or gets hit harder during grinding or clenching, that repeated stress will eventually break the cement bond. We call this occlusal overload, and it's surprisingly common, especially in people who grind their teeth at night without realizing it.
Even a well-made crown won't survive long if it's fighting your bite every time you close your mouth.
Here's how we address it:
Bite adjustment in multiple positions—not just when you bite down, but when you slide your jaw forward and side to side
Night guard recommendations for patients who clench or grind (bruxism)
Material selection based on your individual force patterns and tooth position
Sometimes the solution is as simple as shaving a fraction of a millimeter off the crown. Other times, it's about changing habits or protecting your teeth while you sleep.
Should We Re-Cement or Start Over?
This is the question we get asked most often when a crown comes off. The honest answer? It depends.
Re-cementing works well when:
The crown still fits snugly with no gaps
The margins (edges) are clean and sealed
The only issue was contamination during the original cementation
A remake or modification is needed when:
The tooth prep doesn't provide enough retention
Margins are open, allowing decay or leakage
The bite is fundamentally off and can't be corrected with minor adjustments
We'll always be straight with you about which route makes sense. Sometimes re-cementing buys time; sometimes it just delays the inevitable.
What You Can Do at Home
While the technical work happens in our office, there are simple things that make a real difference in how long your crown lasts:
Floss around it daily—crowns don't get cavities, but the tooth underneath can
Avoid using your teeth as tools (opening packages, biting nails, chewing ice)
Wear your night guard if one was recommended
Let us know right away if you notice a high spot, food packing, or sensitivity around the crown
Catching small problems early almost always means simpler, less expensive fixes.
Serving Kansas City's Neighborhoods with Care
We're proud to serve patients from State Avenue, Argentine, Rosedale, Armourdale, Turner, and surrounding Kansas City, Kansas communities. If you've been dealing with a crown that just won't stay put, we'd be glad to take a look and talk through your options.
If your crown keeps coming off, let's find out why—and fix it for good. Call State Avenue Dental Office in Kansas City, Kansas to schedule a Crown Stability Check. We'll take the time to get it right.