Traditional dentistry practices like using dental fillings containing certain materials have been thought to expose the body to toxic substances and cause infections. So if you have those old silver fillings in your mouth for many years, you may want to know if this is actually true.
1. What is a silver filling?
A silver filling, scientifically referred to as amalgam, is composed of a mixture of metals including silver, tin, copper, zinc and mercury in fixed proportions. Silver fillings have been successfully used for filling decayed teeth for over 150 years. They are durable, and are ideal for the back teeth (molars) which bear the maximum forces while chewing food. However, they require more of the tooth structure to be cut, and can get discoloured with time. Overall, they are deemed excellent when additional strength is required and aesthetics is not a major concern for the patient.
2. What is the toxic content in silver fillings?
As stated above, silver fillings are essentially alloys of certain metallic compounds. Among these, mercury, a naturally occurring but poisonous substance, comprises about 50% of the alloy. Mercury is used as it helps make the filling material pliable. When it is mixed with the other metals, it forms a compound that is mouldable, allowing ease of placement within the decayed tooth. However, some reports emerged stating that small amounts of mercury may be leaked from dental fillings causing certain toxic effects. This put a question mark on the safety of its use in dental practice.
3. How safe are silver fillings?
Despite all reports from the past, the National and International bodies have declared that the use of mercury-containing fillings is safe.
–The World Dental Federation (FDI) stated that the quantity of mercury released from the fillings is so minute that it can be measured in nanograms (ng), which are one billionth of a gram.
–The World Health Organization (WHO) made a statement that there is no evidence of any relationship between silver fillings and chronic degenerative diseases, autoimmune disorders, kidney diseases, or altered brain function.
–The Australian Dental Association (ADA) asserted that the use of mercury-containing dental fillings produces no harmful effects.
4. Are silver fillings safe in children, pregnant & breast feeding mothers?
Silver fillings are generally not used in young children and are also avoided in certain other populations including people with kidney disease, pregnant or breastfeeding women. Dentists suggest other materials for pregnant woman who have decayed teeth. The removal of amalgam fillings is also not recommended for pregnant and breastfeeding mothers. However, there is no evidence that women with existing silver fillings in their mouth should not breastfeed their children.
5. Should they be replaced with tooth-coloured fillings?
Although silver fillings are increasingly giving way to tooth-coloured filling materials such as resin, they are still in use, safe, and need not be replaced unnecessarily.
Scientific bodies suggest amalgam to be a valuable, viable and safe choice for dental patients. There are also reviews which support the position of silver fillings as a safe option for protecting decayed natural teeth, and preventing further harm to the tooth structure.
The Bottom line
Silver fillings do not pose a health risk in general population apart from allergic reactions in few patients. No clinical evidence is available for replacing clinically satisfactory silver fillings with tooth-coloured fillings.