Dental resources · Restorative
How to tell if your filling needs to be replaced.
Fillings don't last forever, but they also don't all need to be replaced on a schedule. Here's how to read the signs that an old filling is failing, and what to do about it before a small problem becomes a crown-sized one.
Reviewed by Dr. Anthony J. D'Addio, DMD
Dr. D'Addio has watched fillings age across two decades of Fulton County patients. The signals worth acting on, and the ones that can wait, are below.
5 min read · Updated 2026
The short answer.
A filling typically needs replacement when you notice one or more of the following: visible cracks, gaps, or chips in the filling material; sharp sensitivity to cold or sweet that didn't exist before; roughness when your tongue passes over it; or a visible dark line at the edge where the filling meets the natural tooth. Routine cleanings catch most of these before you'd notice them at home.
Full details on how composite fillings work at Dunning, including materials, longevity, and what to expect during placement, live on the fillings page. If you're noticing any of the above, call 518-842-3220.
How long does a filling actually last?
The average composite (tooth-colored) filling lasts 7 to 10 years, though many last considerably longer when placed well and maintained with regular cleanings. Silver amalgam fillings from previous decades often last 10–15 years before showing wear at the edges. Several factors affect longevity:
- Location in the mouth, back-tooth chewing surfaces wear faster than smaller fillings on front teeth.
- Filling size, larger fillings have more surface area to fail and absorb more bite force.
- Bite habits, grinding, clenching, or chewing ice all shorten filling life.
- Home care, plaque at the filling margin causes recurrent decay; consistent flossing slows that.
The good news: failure is usually gradual. Routine six-month cleanings catch wear before it becomes structural failure.
Signs your filling is failing, by category.
Four categories of signs to watch for. Any one of them is worth a phone call to the office.
What you can see in the mirror:
- Visible cracks across the filling surface.
- Chips, especially at the edges where the filling meets natural tooth.
- A dark line around the perimeter (often early secondary decay).
- The filling looks worn down compared to the surrounding tooth.
What you can feel:
- Roughness when your tongue passes over the filling.
- The tooth feels sharper than it used to.
- A piece of the filling came loose (don't try to glue it).
How the tooth responds:
- New sensitivity to cold drinks or ice cream.
- Pain when you bite down on something hard.
- Lingering ache after eating something sweet.
- Sharp, fleeting pain that comes and goes.
Behavioral changes you might notice:
- You're avoiding chewing on that side of your mouth.
- Food keeps getting stuck around the filling.
- The tooth feels different after a hot or cold drink.
What happens if you wait?
The honest answer: it depends on what's failing. Small chips or worn edges might give you another year before they become a real problem. Visible cracks or new sensitivity usually mean decay is already spreading underneath, and waiting can turn a routine filling replacement into a crown, a root canal, or, in extreme cases, an extraction.
The math is usually simple: an early filling replacement costs significantly less than the larger procedures that follow if it's ignored. A failing filling that's caught at a routine cleaning is a 30–60 minute fix. The same filling left for two more years can easily become a crown plus a root canal, a much bigger investment in time, money, and recovery.
Routine cleanings, the kind covered in the general and preventive dentistry overview, catch most failing fillings before patients notice anything wrong.
Common questions
Practical answers, plainly written.
Can I just have my filling repaired instead of fully replaced?
Sometimes, yes. Small chips on the surface of an otherwise sound composite filling can occasionally be bonded with new composite material rather than replaced entirely. This is most appropriate when the underlying tooth is healthy, the existing filling is well-fitted, and the chip is purely cosmetic or minor. If there's any sign of decay at the margin, a crack extending into the tooth, or the filling is more than a few years old, full replacement is usually the better answer because the underlying problem won't be addressed by a surface repair. We evaluate each filling individually rather than defaulting to repair or replace. Call (518) 842-3220 if you want a specific tooth assessed.
Why does my filling hurt months after it was placed?
Pain that develops months or years after a filling was placed usually means one of three things: the filling has cracked or worn through, new decay has developed underneath the filling, or the bite changed slightly and the filling now sits high. The first two require restoration replacement; the third can sometimes be fixed with a quick bite adjustment in a 10-minute visit. Lingering pain to hot or cold that builds up rather than fading quickly can indicate the nerve is involved, which may require a root canal in addition to filling replacement. The longer you wait with active pain, the more likely a smaller fix grows into a larger one. Call the office and the front desk will get you in.
Do I need to replace silver amalgam fillings just because they're silver?
No. Silver amalgam fillings remain FDA-approved and considered safe for dental use. The decision to replace an amalgam filling should be based on its condition, failing edges, recurrent decay, cracks, or wear, not on the material itself. Replacing perfectly functional amalgam fillings just because they're not tooth-colored isn't medically necessary and isn't something a practice focused on right work, right amount, right time would recommend. At Dunning, we replace failing amalgams with tooth-colored composite when they need to be replaced, which means most patients gradually transition to all-composite restorations as the older work naturally reaches the end of its life. We don't push wholesale replacements. Full details on our composite work are on the fillings page.
Can a failed filling cause other problems beyond the tooth itself?
Yes, in two ways. First, an open margin between a failed filling and the tooth lets bacteria reach the inner pulp tissue, which can cause infection and eventually require root canal therapy. If left long enough, that infection can spread to surrounding bone. Second, a tooth weakened by a failing large filling can crack under normal bite forces, and a crack that extends below the gum line often means the tooth cannot be saved at all. The cost difference between replacing a filling early and addressing a fracture or abscess later is significant, both in dollars and in chair time. Routine cleanings every six months are the cheapest way to catch failing fillings early.
How do I prevent my fillings from failing prematurely?
Three habits matter most. First, floss daily, the most common reason composite fillings fail at the margin is plaque accumulation right at the edge of the filling, which causes recurrent decay underneath. Second, avoid chewing ice, hard candy, popcorn kernels, and similar high-impact foods, these break composite material and can crack the underlying tooth. Third, if you grind your teeth (most grinders don't know they do), a night guard from your dentist extends the life of every filling in your mouth significantly. Routine six-month cleanings catch failing fillings before they become structural problems. Together, these habits often double the working life of a composite filling. Call (518) 842-3220 to schedule a checkup.
Don't ignore a tooth that feels off.
Failing fillings caught early are 30-minute fixes. Ignored, they become much larger procedures.
A legacy of family dentistry you can trust.