Reviewed By Dr. Jodi Kuhn
Reading time: 4 minutes
A cavity can develop under or around an existing filling. Fillings repair areas damaged by tooth decay, but the remaining natural tooth can still develop new decay, especially if the filling begins to wear, crack, or separate from the tooth.
We provide dental care for the whole family at our offices in Denver, Aurora, Thornton, and Hampden. We proudly accept Medicaid and make quality dental care accessible for every child.
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At our Denver and Aurora locations, Youth Dentistry & Orthodontics and Youth Vision are conveniently located in the same building. This means your child can receive both dental and vision care at one familiar location, without extra travel or scheduling stress.
Table of Contents
Fillings Can Wear Down Over Time
Dental fillings can last for years, but they do not last forever. Daily chewing, grinding, temperature changes, and normal wear can gradually affect the filling or the bond between the restoration and the tooth.
Small cracks or gaps can sometimes form around the edges. Plaque and bacteria can collect in these areas, allowing a cavity to develop along the edge of the filling or underneath it.
A filling that has chipped or broken can also leave more of the tooth exposed. If you notice a chipped dental filling, new sensitivity, or discomfort around a restoration, it is a good idea to have us check it.
What Does Decay Under a Filling Feel Like?
Decay under a filling does not always cause symptoms right away. In some cases, we find it during a routine dental exam before the tooth starts to hurt.
When symptoms do develop, you may notice:
- New sensitivity to hot, cold, or sweet foods
- Pain or tenderness when biting or chewing
- An ache in a previously treated tooth
- A rough, cracked, or loose filling
- Darkening or discoloration around the filling
These symptoms do not automatically mean there is a cavity under the filling. A cracked tooth, damaged restoration, or other dental problem can cause similar symptoms, so an exam can help us determine what is happening.
How Do We Find a Cavity Under a Filling?
Decay under a filling may not be visible just by looking at the tooth. During a routine dental exam, we can examine the condition and edges of existing restorations and look for changes that may indicate a problem.
Dental X-rays can also help us identify decay that develops in areas we cannot see directly, including around or beneath some restorations. Finding a problem earlier may allow us to treat the tooth before the decay becomes more extensive.
Regular exams are especially important because a filling can look normal from the outside even when a problem is developing around it.
How Is a Cavity Under a Filling Treated?
Treatment depends on how much decay is present and how much healthy tooth structure remains. For a smaller area of decay, we may remove the old filling, clean out the decayed portion of the tooth, and place a new filling.
If decay has weakened a larger portion of the tooth, another filling may not provide enough support. In that situation, a dental crown may be recommended to cover and protect the remaining tooth.
If decay reaches the pulp inside the tooth, additional treatment such as root canal therapy may be necessary. The appropriate treatment depends on the condition of the individual tooth.
Can You Get a Cavity Under a Crown Too?
A cavity can also develop under or along the edge of a dental crown. Although the crown itself cannot develop tooth decay, the natural tooth underneath it can.
Decay may begin where the crown meets the tooth, particularly if bacteria and plaque collect along the margin or the crown no longer fits as closely as it once did. A cavity under a crown may eventually require the crown to be removed so we can treat the tooth beneath it.
Have an Older Filling Checked
At Youth Dentistry & Orthodontics, we provide preventive and restorative dental care for the whole family at our Denver, Aurora, Thornton, and Hampden locations. If you are concerned about an old filling or possible tooth decay, contact us to schedule an appointment.
To schedule an appointment, contact the location most convenient for your family:
- Denver Youth Dentistry & Orthodontics: (303) 825-2295
- Aurora Youth Dentistry & Orthodontics: (303) 343-3133
- Thornton Youth Dentistry & Orthodontics: (303) 280-8878
- Hampden Youth Dentistry & Orthodontics: (720) 826-3694
FAQs
Can a cavity under a filling be seen on an X-ray?
Dental X-rays can often help us identify decay around or beneath a filling that may not be visible during a visual exam. The appearance of the restoration and the location of the decay can affect how easily it shows on an X-ray.
Does a filling need to be replaced if there is no pain?
Not necessarily. A filling may need replacement if it becomes cracked, loose, worn, or develops decay around it, even when the tooth does not hurt. We can check existing restorations during routine exams and recommend replacement when there is a clinical reason to do so.
How long do dental fillings last?
There is no single lifespan for every filling. How long a restoration lasts depends on factors such as its material and size, the tooth’s location, chewing forces, oral hygiene, and habits such as teeth grinding.
Can you get another filling in the same tooth?
If a tooth develops new decay and enough healthy tooth structure remains, we may remove the old restoration and place a new filling. If the tooth has lost too much structure, a crown or another treatment may provide better support.
