White vs Silver Fillings: How to Choose a Dental Filling

What is a white (composite) filling?

A white filling is a resin material mixed with fine glass particles, known as composite. Your dentist matches the shade to your tooth, places it in layers and hardens each layer with a special light, so it bonds directly to the tooth.

Its main advantage is that it preserves as much healthy tooth as possible, because the dentist usually does not need to remove extra structure to hold it in place. It suits front and back teeth with small to medium cavities. On the other hand, it needs to be kept completely dry while it is placed, and its surface can pick up stains over time with lots of tea, coffee or smoking.

What is a silver (amalgam) filling, and is it safe?

A silver filling is a mix of silver, tin and copper bound with mercury, called amalgam. It has been used for more than a century and is valued for its strength and its ability to withstand chewing forces on back teeth.

Many people worry about the mercury. In amalgam, mercury is bound with the other metals into a stable solid, and major health bodies consider it safe for most adults. However, some authorities advise avoiding it in pregnant and breastfeeding women, young children, and people with an allergy to its components or with kidney disease, and many countries are phasing it down for environmental reasons. Removing a sound silver filling just out of worry is usually not recommended, because removal costs the tooth more of its structure.

What are ceramic inlays and onlays?

When decay or a fracture is large, your dentist may suggest a filling made outside the mouth from ceramic or a similar material and then bonded to the tooth. If it sits within the tooth's cusps it is called an inlay; if it covers one or more of the chewing cusps it is called an onlay.

These restorations look very natural, resist wear and staining well, and conserve more tooth than a crown. They usually require two visits or digital in-clinic milling, and they cost more than a direct filling.

Which filling lasts longest?

How long a filling lasts varies a lot between people. In general, silver and ceramic restorations tend to last longer on average, but a well-placed white filling often lasts many years with good daily care. These are the main factors that shorten the life of any filling:

• A large filling, which carries more biting force.
• Grinding or clenching your teeth at night.
• New decay around the edges of the filling from poor cleaning.
• Chewing ice or hard objects, or opening packages with your teeth.
• Frequent sugary or acidic drinks between meals.

When is a crown better than a filling?

A filling suits a tooth that still has much of its natural structure. If the tooth is badly weakened, its remaining walls can crack under chewing pressure however good the filling is. In that case a crown or an onlay may be the safer option, because it wraps around the tooth and protects it. Your dentist may discuss this option when you have:

• Decay or a fracture involving a large part of the chewing surface.
• A root-canal-treated tooth, especially a back molar.
• A cracked tooth that hurts when you bite.
• A large old filling that keeps breaking or needing replacement.

How should I care for my teeth after a filling?

A white filling sets immediately, so you can eat once the numbness wears off. With a silver filling it is best to avoid heavy chewing on it for the first 24 hours. Either way, wait until the anaesthetic has worn off before eating so you do not bite your cheek or tongue without noticing.

Mild sensitivity to cold or heat is normal for a few days and can last up to about two weeks. If the filling feels high and touches the opposite tooth before the others, go back to your dentist to have it adjusted, as this can cause lasting pain.