Silver fillings have been used worldwide very successfully for decades and many people have several silver fillings in their mouths. These types of fillings are usually made of an alloy of silver, mercury copper and tin. They are cheap, easy to place, hard wearing, and the silver ions exert an antibacterial effect which can help inhibit further tooth decay in the cavity.
There are three main reasons why people consider replacing their old silver fillings; poor appearance, concerns over mercury toxicity and age of the fillings and I will consider each of these in turn.
1. Appearance - the ideal fillings material will of course of safe, easy to use, hard wearing, affordable, and tooth coloured. The tooth coloured alternative to silver fillings is a kind of plastic resin material called composite. Composite technology has come on enormously over the years. In the past there were concerns that composite fillings were not as hard wearing or long lasting as silver fillings, but there is no reason why a good quality, well placed composite filling used in the right situation should not give many long years of service. They are usually more expensive, partly due to material cost, and partly because they do take a little longer to place than silver fillings. However, the results can be very pleasing cosmetically and some patients are keen to move on from their old silver fillings to more cosmetic tooth coloured fillings. However it must be borne in mind that drilling out an old silver filling that is especially deep, or close to the nerve of the tooth carries a small risk of irritating the nerve. This may only be temporary but if the nerve does not settle then root canal work can become necessary. However this is very rarely a problem and if you would like to replace any old silver fillings with tooth coloured fillings you can discuss with your dentist first if any of them are especially deep, and decide together what would be the best option for you.
2. Mercury toxicity - high levels of mercury are indeed toxic to humans. However the level of exposure from silver fillings is very low, and if you eat a lot of seafood you are likely to be exposed to more mercury through your seafood consumption than through your silver fillings. Large scale studies have failed to identify convincing evidence of harm caused to individuals from having silver fillings. (Dentists are exposed to far higher mercury levels than their patients.) The exception to this is in rare individual cases of allergy to components of silver fillings. However an absence of evidence to conclusively prove harm from mercury in dental fillings is not the same as conclusive proof that mercury in dental fillings is always safe. It is possible that some people are more susceptible to mercury toxicity than others and some smaller studies due suggest possible benefits to some individuals from having their silver fillings removed. However, due to general concerns regarding the environmental impact of industrial mercury processing, many countries are phasing out silver fillings. As tooth coloured fillings materials continuously improve silver fillings are gradually being superseded.
3. Age of the fillings - as silver fillings get very old they gradually start to deteriorate. It's not unusual to see silver fillings that have been in place for 20 or 30 years. After such long periods of time they start to appear corroded and pitted on the surface and the edges start to degrade. At this stage the fillings often no longer form a good seal for the cavity and there is often decay underneath the fillings. Fortunately due to the antibacterial effects of the silver ions this decay progresses very slowly. However at this stage the fillings are really reaching the end of their useful life and it is worth considering replacing them.
If you would like to discuss replacing your silver fillings then feel free to contact me, or come and see me at The Fountain Dental Practice for a free consultation.