Dental Fillings: A Patient Guide

What a filling does—and what it does not do

A filling replaces the part of a tooth that has been lost to decay or limited damage. The dentist removes tissue that cannot be kept, then rebuilds the space so the tooth can function again.

It is a repair, not a reset button. The remaining tooth can still develop decay, and the filling itself will be exposed to years of chewing, temperature changes, and everyday wear.

Very early decay is a little different. Before the enamel has broken down into a true cavity, fluoride, improved plaque removal, and changes to frequent sugar exposure may sometimes stop or reverse the process. Once there is a hole in the tooth, a filling is a common next step.

If the difference is not clear, ask the dentist to show you the area and explain why it needs treatment now rather than monitoring.

What the appointment feels like

The tooth is usually numbed with local anesthetic. You may still notice pressure, water, noise, and vibration, but you should not have to tolerate sharp pain. Raise a hand if you need the dentist to pause.

Once the area is numb, the dentist removes the decay and prepares the tooth for the chosen material. Tooth-coloured composite is often placed in layers. Each layer is hardened with a curing light, then the filling is shaped and polished.

The bite check at the end is more important than it may seem. Numbness can make it difficult to judge how your teeth meet, so take your time. If the filling feels taller than the surrounding teeth once the freezing wears off, call the clinic. A small adjustment can make a big difference.

Which filling material is best?

There is no single material that wins in every situation.

Composite resin can be matched to the tooth and bonds to the remaining structure. It is widely used, especially in visible areas. It needs good moisture control during placement and, like any filling, can wear, stain, or chip.

Dental amalgam is silver-coloured and has a long clinical history. Whether it is suitable depends on the tooth, the size and location of the cavity, and the circumstances in which the filling must be placed.

Glass ionomer and other materials have useful roles too. If a large portion of the tooth is missing, a direct filling may not provide enough support; an inlay, onlay, or crown may be discussed instead.

Rather than asking for a material by reputation alone, ask why the dentist recommends it for this tooth.

The first few hours afterward

Your lip, cheek, or tongue may stay numb for a while. Be careful with hot food and drinks, and avoid chewing the numb tissue by accident. Follow any eating instructions from the clinic.

Some short-term sensitivity to cold, sweets, or pressure can occur. It should generally settle rather than intensify. Contact the dentist if you develop severe pain, swelling, worsening sensitivity, or a bite that continues to feel uneven.

A filling does not automatically mean the tooth's nerve is healthy forever. Deep decay can irritate the pulp inside the tooth, and occasionally symptoms become clearer after the cavity has been restored. The dentist should explain what to watch for when the filling was close to the nerve.

How many years should a filling last?

It is tempting to look for one number, but filling lifespan depends on too many variables for a useful guarantee. A small filling on a lightly loaded surface is not doing the same job as a large restoration in a back tooth.

Grinding, clenching, dry mouth, diet, cleaning habits, filling size, and the amount of healthy tooth left all influence longevity. Regular exams allow the dentist to check the edges and surrounding tooth.

An older filling does not need replacement simply because it is old. There should be a clinical reason, such as decay, fracture, wear, or a failing edge.

Preventing decay around the repair

Plaque can collect where filling material meets tooth, and a different surface of the same tooth can develop a new cavity. Brush twice daily with fluoride toothpaste and clean between the teeth every day. If your mouth is often dry, mention it; saliva plays an important role in protecting teeth.

Our brushing and flossing guide covers the daily routine, and the preventive visit guide explains how follow-up timing is chosen.

One of the best questions after a filling is not “How long will it last?” but “Why did the cavity form here?” The answer may point to a tight contact, frequent sipping, dry mouth, or a spot your toothbrush simply was not reaching. That is the information that can help prevent the next one.