An amalgam filling is a silver colored restoration that is made from a mixture of metals. This mixture includes around 50% mercury combined with silver, tin, copper, zinc and other metals.
An amalgam (sometimes called a ‘silver’ or ‘metal’) filling is used on back teeth only in modern dentistry. Amalgam has been used for over a hundred years as a filling material. It is still used every day by the majority of dentists. It has its advantages as a restoration material but also its problems:
Advantages of Using Amalgams:
- Long-lasting. They typically last 7 years and can last a lifetime if well looked after.
- Hard-wearing. As a metal mixture, amalgam is strong under biting and chewing forces.
- Economical. It is the least expensive filling material.
- One can usually can be completed in one visit.
- The material is relatively quick and easy for the dentist to use.
- There is a long track-record of amalgam as a safe and useful filling material. Good scientific research backs this up.
Problems With Amalgams:
- Appearance. They are not tooth-colored so are unnatural looking and obvious to spot.
- Amalgam by itself does not adhere (stick) to the tooth.
- When drilling the tooth before placing the filling, the dentist may have to remove more weak parts of the tooth than s/he would have to with a ‘white’ filling. This will depend on the shape of the cavity, which is determined by any decay.
- Corrosion. They can leak through the tooth slightly to make the tooth discolor over time, even if the original filling is not visible.
- Allergy to one of the metals, including mercury. True allergy to mercury remains rare.
- Concerns over safety of mercury. Good scientific research all points to the safety of these fillings on the whole. Mercury changes chemically when combined into amalgam. This changed form is harmless. The exposure to mercury from dental amalgam is very low, and similar to that from other environmental sources such as fish.
Amalgam filling material is still used everyday by most dentists. It is considered safe to use and is very effective in a lot of circumstances. There are problems with amalgam. The main ones are it’s appearance and inability to bond/stick to teeth.