Amalgam is one of the most common types of filling material to replace part of a tooth that has been lost or damaged. Amalgam is silver in colour and is made from a mixture of different metals including silver, tin and copper and mercury. It is often used to restore back teeth and is used as a core material underneath other dental restorations such as crowns. 

• Why do I need an amalgam filling
• Treatment
• Benefits of treatment
• Risks of treatment
• Alternatives
• What happens after treatment is finished
• Questions you may want to ask
• Maintaining good oral hygiene at home

Why do I need an amalgam filling

Common reasons to use amalgam include: 

• Replacing an old or failing amalgam filling
• When it is difficult to control moisture around a tooth that needs a filling
• When a patient has a high risk of tooth decay 

What happens during treatment

An amalgam filling typically takes 1 appointment. The procedure for an amalgam filling can vary but you can expect the following steps: 

1. The tooth will be examined to plan the filling. This will include taking an x-ray. 
2.  The tooth and surrounding areas will be anaesthetised to make the procedure more comfortable. 
3. The cavity is prepared to receive the amalgam filling using a variety of instruments. This may include removing decay or a previous filling. 
4. The amalgam filling is placed and shaped. Shaping the amalgam is important to ensure your teeth close together comfortably. 
5. The amalgam filling is polished leaving a shiny, smooth surface. 

Treatment

Advantages 

If looked after, amalgam fillings can last up to 20 years. 
Dental amalgam fillings are robust, hard-wearing and can withstand biting forces, so are used on the molars (back teeth), which are used to grind food.  

Risks 

Amalgam is silver in colour so does not match the colour of the tooth. 
There has been concern about the safety of dental amalgam, due to the mercury content. The limit of mercury is 200ug per week for an average individual. In the case of a patient with 8 amalgam fillings, the dose amounts to 14ug per week. In fact, 1 tin of tuna can amount to 60ug per can! 
It is possible to experience sensitivity after a filling, but this will likely subside after a couple of days. Extremely hot and cold drinks are usually the cause of this sensitivity. 
It is possible that bacteria can get under an amalgam filling and cause decay. It is therefore important to reduce/eliminate dietary sugars and brush around the filling twice a day with fluoride toothpaste. 
Pregnant women should not receive an amalgam filling. 
Whilst the use of amalgam within dentistry is decreasing, this is for environmental rather than health reasons. 

Alternatives

We will always discuss the options available to you in depth before any decisions are made. 

There are 2 other types of fillings that may be an option, your dentist will be able to explain further: 

• Composite (white) fillings - these are used when a filling is visible (e.g. front teeth), when the cavity is the correct shape and when there is good moisture control at the back of the mouth.
• Glass ionomer cement - these are used in areas where there are low biting forces.

What happens after treatment is finished

Ideally you should wait 24 hours until biting on an amalgam filling as it can take this long to fully harden. The tooth may feel sensitive after treatment, but this should subside. If anaesthetic has been used, be careful when having extremely hot and cold drinks for at least 2 hours. The new filling might feel unusual in the mouth but patients quickly get used to the new restoration. 

Please make an appointment for a check-up, or if the amalgam filling feels uncomfortable or painful.

To check that you and your dental professional are happy with the outcome of your treatment, you will be reviewed after your treatment is finished.  

When all of your dental treatment is complete, you will be discharged from the dental school. We advise that you find a dentist outside the dental school to continue to look after your teeth and restorations. 

Questions you may want to ask

• Which filling material is most appropriate for my tooth?
• Are there any oral hygiene measures I can do to best look after my amalgam filling?
• When should I make an appointment if the pain or discomfort persists?

Maintaining good oral hygiene at home

Maintaining good oral hygiene is crucial for healthy teeth and gums, and will help reduce the risk of decay and gum disease. Brush your teeth twice daily for 2 minutes with fluoride toothpaste and clean between your teeth with floss or interdental brushes.  

Smoking and alcohol increase the risk of oral disease. If you want to quit smoking or reduce your alcohol intake, please talk to the clinician you see for further advice.  
It is important to attend dental check-ups regularly, as this will help your dentist to identify any dental disease early.