Cavity Under Filling: What to Do and How to Fix It

Dental fillings are designed to restore a tooth after decay, but like anything else, they don’t last forever. Over time, it’s possible for new decay to develop under or around an old filling, a condition that many patients may not realize until they start to experience discomfort.

If you’ve ever wondered why your tooth hurts under a filling or suspected a cavity beneath an existing restoration, you’re not alone. This article will explain what’s happening, why it occurs, and how your dentist can fix it.

Can a Cavity Form Under a Filling?

Yes. Even if a tooth already has a filling, cavities can still develop underneath it. This usually happens when:

• The filling is old or worn down
• The seal between the filling and the tooth has weakened
• Tiny cracks allow bacteria and food particles to slip underneath
• Poor oral hygiene or diet increases the risk of decay

Once bacteria find their way under a filling, decay can spread beneath the surface without being immediately visible.

Signs You May Have a Cavity Under a Filling

It can be tricky to spot decay beneath a filling on your own, but some symptoms to watch for include:

• Tooth pain when chewing or biting
• Sensitivity to hot, cold, or sweet foods
• A filling that feels loose, chipped, or rough
• Discoloration around the edges of the filling
• Persistent bad breath or a bad taste in the mouth

If you notice these symptoms, it’s important not to ignore them. The problem will only get worse over time if untreated.

Why You Shouldn’t Wait to See a Dentist

A cavity under a filling won’t heal on its own. In fact, the decay can spread deeper into the tooth, leading to:

• Larger cavities requiring more extensive restorations
• Tooth fracture if the filling no longer supports the structure
• Infection or abscess that may require a root canal
• In severe cases, tooth loss

The sooner you see a dentist, the easier and less costly the treatment will be.

How Dentists Fix Cavities Under Fillings

At Karr & Hardee Dentistry, Dr. Karr and Dr. Hardee have years of experience treating hidden decay under fillings. Depending on the severity, treatment may include:

• Replacing the filling – Removing the old filling, cleaning out decay, and placing a new restoration.
• Inlay or onlay – For larger areas of decay, a custom-made restoration provides extra strength.
• Dental crown – If the tooth structure is weak or cracked, a crown may be needed for long-term stability.
• Root canal therapy – If decay reaches the tooth pulp, root canal treatment can save the tooth.

Our dentist will carefully evaluate the tooth with X-rays and an exam to recommend the best option.

Can You Prevent Cavities Under Fillings?

While fillings don’t last forever, you can reduce your risk of developing new cavities by:

• Brushing twice daily with fluoride toothpaste
• Flossing once a day to remove hidden plaque
• Limiting sugary snacks and drinks
• Visiting your dentist regularly for checkups and X-rays

Routine dental care helps identify small problems before they become major issues.

Final thoughts

A cavity under a filling is more common than many people realize, but with prompt care, it can be fixed before it causes serious damage. If your filling feels loose, your tooth hurts, or you suspect decay, don’t wait. Replacement may be the best solution.

Schedule an appointment with Karr & Hardee Dentistry today. Dr. Karr and Dr. Hardee can evaluate your tooth, replace the damaged filling, and protect your smile for the long term.