Dentists have been using dental amalgam for well over a century and a half. It is currently the most tested dental material to date, although its safety as a dental filling compound has been questioned. The controversy is primarily due to its ingredients, mainly mercury. That being said, there are only a few studies that conclusively show that amalgam (or silver) fillings are actually dangerous.
There are, however, other choices available to the public that are considered to be a better choice. Composite (e.g. white) fillings offer decided advantages over Amalgam (e.g. silver) fillings.
Amalgam Fillings
Dental amalgam is a mixture of approximately 50% mercury and 50% of an alloy powder, usually composed of silver, zinc or palladium. This mixture is distributed in capsules that are shaken by the dentist to mix both ingredients thoroughly. When this shaking process is completed, the resulting soft metallic ball, is removed from the capsule by the dentist and the soft material is placed into the cavity in bulk and pressed into the cavity until the cavity is filled. The dentist then carves the material to make it fit the bite pattern of the patient’s tooth. This process has to occur in just a few short minutes, since the material will harden to a point where it is no longer viable.
Advantages
- Amalgam fillings are strong due to being composed of metal and can withstand heavy biting pressure, dictating use primarily for the back teeth.
- Amalgam filling material is relatively inexpensive.
- Most dental insurance companies cover amalgam fillings.
Disadvantages
- Amalgam filling material contains mercury and other metals. Although there have been no conclusive studies relating to a danger due to mercury in amalgam, the FDA did admit in July of 2008 that silver dental fillings may not be safe.
- Some people experience a period of hot and cold sensitivity after having an amalgam filling.
- Amalgam fillings do not harden immediately. Therefore, it is not good to chew on that specific tooth for a couple of hours after the filling procedure.
- More tooth structure is lost due to a larger preparation area being required for the filling.
- The use of amalgam fillings are on the decline and are not used by all dentists.
Composite Fillings
Composites are made from polymers, which form a hard plastic. Filler compounds are placed with the polymers to add strength to the material. Quartz, silica or barium are often used as fillers. Different from the amalgam compound, no time constraints exist for placement of composites. Most are cured by light, so the dentist has time to place and carve the material before hardening it with the light.
Advantages
- The composite filling material does not contain any mercury, but rather acrylic and glass particles.
- The filling material can be colored to match the tooth which looks very natural.
- Composite filling material is hard at the completion of the procedure, so it can be chewed upon immediately after leaving the dental office.
- Less of the tooth structure is lost, since a smaller preparation area is required.
Disadvantages
- Composite filling material is more expensive.
- A composite filling procedure can take a bit longer to complete.
- Staining of a composite filling can occur over time depending on the use of tobacco or consumption of tea and coffee.
- If the teeth are bleached the fillings do not get any whiter.
- Composite fillings are not as strong on back teeth as amalgam.
- Insurance companies will not always pay for composite fillings on back teeth.