Can I Get a Cavity Under a Dental Filling?

A majority of people will get a cavity, also called tooth decay, at some point in their lifetimes. You are likely familiar with the treatment of this early form of tooth decay: a dental filling. But once a cavity is treated, is it gone for good?

When a dentist treats a decayed tooth with a filling, the cavity is removed completely. However, a new cavity can form on the same tooth in a different area or even under the filling at a later time.

Dentists refer to this condition as recurrent tooth decay. Read on to learn more about recurrent decay, including where it comes from, its treatment, and prevention tips.

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What Is Recurrent Tooth Decay?

A cavity is a form of tooth decay in which the enamel or underlying tooth structure is dissolved by acids produced by oral bacteria, leaving a hole in the surface of the tooth. The dentist resolves this issue by drilling away the damaged part of the tooth and filling the resulting hole with a dental filling.

Recurrent tooth decay develops when you form another cavity on another part of the same tooth. But it can also occur when your filling or another restoration, like a dental crown, sustains damage or is exposed to harmful oral bacteria.

Over time, all fillings deteriorate in the oral environment, allowing bacteria and their harmful byproducts to seep under the filling. We often say filling is “leaking” when this happens, resulting in recurrent decay.

Recurrent decay can also occur when a filling, crown, or bridge does not fit the tooth well or becomes loose, allowing gaps for bacteria to seep in under the restoration.

If you have loose or worn dental work, plaque and other harmful substances can infiltrate the vulnerable underlying area of the tooth. A new cavity can form there, resulting in this recurrent decay.

How Will My Dentist Treat Recurrent Decay?

Your dentist can treat recurrent decay as they would an initial cavity. They will need access to the affected area of the tooth, so they will first remove prior fillings or crowns. You will receive a local anesthetic to ensure you remain comfortable during this procedure.

Then the dentist will remove the decay and place a new filling. If the area is small, it may be restored with the new filling. This is a good reason to have regular exams and x-rays so that cavities can be discovered in the early stages. When the cavity becomes more extensive, then more extensive treatment may be required, such as a crown or a bridge or possibly requiring root can treatment.

Can I Prevent Cavities Forming Under Dental Work?

You can keep your dental fillings and restorations safe from damage and prevent this type of recurrent decay through several preventative measures.

As mentioned above, regular dental visits, including cleanings, exams, and x-rays, are important in diagnosing decay early. Your dentist may recommend replacing aging, degrading fillings or ill-fitting restorations before damage from recurrent decay occurs.

You can also prevent cavities in general with healthy oral hygiene practices. This involves flossing daily and brushing your teeth at least twice each day. It is important to keep the tooth structure around any fillings, crowns, or other restorations meticulously clean.

Acidic and sugary foods and drinks heighten your risk for cavities. Avoid added sugar where you can and consider brushing or at least rinsing with water after eating these types of foods. This helps remove bacteria, their byproducts, and sugary or acidic residue from your teeth and can protect your dental health.