How Tooth Decay Is Treated

What is tooth decay?

Tooth decay happens when bacteria in the mouth turn sugars from food and drink into acids. These acids dissolve the mineral layer of the enamel over time. Early decay may cause no pain, which is why regular check-ups matter. Decay that goes unchecked can reach the inner layers of the tooth and the nerve.

Decay is one of the most common oral health problems worldwide, according to the World Health Organization, and it is largely preventable with good habits and access to care.

How is early decay treated?

Small areas of decay are usually treated with a tooth filling. The decayed part is removed, and the space is filled with a tooth-coloured material that matches the rest of the tooth. Most fillings are placed in one visit under local anaesthesia.

In some cases, the decay is caught even earlier. A dentist may recommend fluoride treatment or sealants on the chewing surfaces of back teeth, which can help the enamel repair itself and prevent decay in deep grooves.

When is a root canal needed?

If decay reaches the nerve, the tooth may become painful, sensitive to heat or cold, or swollen. In this case, a root canal treatment may be needed to remove the infected nerve tissue, clean the canals and seal them. The tooth is then restored, usually with a filling or crown.

A root canal aims to keep your natural tooth. Early treatment tends to be simpler than treatment for a tooth that has already become severely infected.

When is a crown needed?

A crown covers and protects a tooth that has lost a large amount of structure to decay, or a tooth that has had a root canal. Crowns are often made from strong, tooth-coloured materials. Your dentist will explain whether a crown or a filling is the better choice for your tooth.

How can I prevent tooth decay?

Brush twice a day with fluoride toothpaste, for two minutes each time. Clean between your teeth every day, because decay often starts in the spaces that brushing cannot reach. Reduce how often you eat or drink sugary foods, and keep sugary drinks to mealtimes where possible.

Regular check-ups help catch decay early, and the dentist can apply fluoride or sealants where they are helpful. The NHS advises limiting sugar and using fluoride toothpaste as part of a daily routine.

How do I know if I need treatment?

Common signs include sensitivity to sweet or cold foods, a visible hole or dark spot on a tooth, food that gets stuck in one place, or a toothache that comes and goes. Some decay causes no symptoms at all, so a check-up is the only reliable way to know.

Book an appointment as soon as you notice any of these signs. Early treatment is usually quicker and more comfortable for everyone.

How do fillings and crowns differ?

A filling restores a tooth that has lost a small or moderate amount of structure. It is usually placed in one visit and is a conservative option that keeps as much of the natural tooth as possible. A crown covers and protects the whole tooth, and it is recommended when a large part of the tooth has been lost.

Crowns usually need two visits, while fillings are often completed in one. Your dentist will explain which option is more suitable for the amount of tooth that remains, and how long each is expected to last with good care.

How does decay affect children's teeth?

Children's baby teeth can decay quickly, because the enamel is thinner and sugars are often eaten frequently through the day. Decay in baby teeth can cause pain and infection, and it can affect the adult teeth developing underneath. Early treatment helps children stay comfortable and keeps their smile healthy.

Our kids dentistry service focuses on prevention, with fluoride and sealants where appropriate, and gentle treatment when decay is found. Parents are welcome to be present during appointments.

What do I do if a filling falls out?

A filling can come out because of wear, a new cavity underneath, or a bite that puts uneven pressure on the tooth. If it falls out, try to keep the tooth clean and avoid chewing on that side. Contact the clinic to arrange an appointment, because the exposed tooth can become sensitive and is at greater risk of decay.

Do not try to glue the filling back in yourself with household products, as these can irritate the gums and do not protect the tooth. Your dentist will check the tooth, decide whether the filling can be replaced, and advise whether a larger restoration is needed.

Why does decay return under an old filling?

Fillings are not permanent, and they can break down over time. Small gaps can form at the edge of the filling, where bacteria and food can collect. Decay can then develop underneath or beside the filling, even though the original cavity was treated well. This is one reason regular check-ups matter: a dentist can see the edge of a filling on an X-ray or during an examination and replace it before decay spreads.

Good daily cleaning between the teeth helps protect the margins of fillings, and limiting sugary foods reduces the acid attacks that make decay more likely.