Fill the Gap

Amalgam versus metal-free dentistry

Tooth filling is a common procedure that fills up cavities in the mouth. There are three different types of fillings.

Amalgam

Most people recognise amalgam, in use for about 150 years, as silver fillings. Dental amalgam is a mixture of mercury, and an alloy of silver, tin, and copper. Mercury makes up 40-50% of the compound because it is the only element that will bind these metals in a way that they can be easily manipulated into a tooth cavity. Amalgam fillings are relatively inexpensive, durable and time-tested. However, amalgam blackens over time and can give teeth a gray appearance. They do not strengthen the tooth and can–in cases of large fillings–expand and crack teeth. Another major concern is that mercury can leach out of the fillings and cause a variety of ailments. So far though, studies have not provided direct evidence of adverse health effects from amalgam mercury. Still, some countries like Austria, Canada, Germany, and Sweden restrict the use of amalgam as a dental filling due to the wider environmental effects of mercury and possible adverse effects in some individuals from low mercury intake.

Composite resin

Composite fillings, also known as white fillings, have been around for about two decades. They are composed of an organic polymer known as BIS-GMA, and inorganic particles such as quartz, borosilicate glass, and lithium aluminum silicate.

They have the advantage of requiring more conservative tooth preparation (less drilling), strengthening the tooth, and are more aesthetic. However, they are more technique-sensitive for the dentist to place. Composite fillings are also relatively more plaque-retentive and susceptible to decay due to its shrinkage and rough surface. In rare cases, polymerisation of the filling can cause sensitivity in the tooth.

Ceramic or porcelain fillings

Ceramic or porcelain is a non-crystalline glass composed of silicon and oxygen, used for tooth-coloured crowns, veneers and bridges. Nowadays it is used widely for fillings too. It is highly aesthetic and is the filling of choice for appearance-conscious people. Previously ceramic was not used widely because of its relatively higher cost. It was also more technique-sensitive and required two visits to place the filling. However modern day technology in the form of the CEREC computer restoration system allows ceramic fillings, veneers, and crowns to be fixed in one visit. How does it work?

After the tooth is prepared, it is scanned with an electronic camera. The filling or crown is designed from this scanned image and then automatically milled from a solid ceramic block. This is accomplished so precisely that it can be accurately fitted and durably bonded to the prepared cavity, giving the tooth stability and requiring
less drilling.

The CEREC ceramic has similar characteristics as healthy enamel, be it in strength, aesthetics, and expansion. This is equivalent to placing a natural filling in a cavity. It is as hard-wearing as normal enamel and not affected by temperature changes, thereby eliminating tooth sensitivity problems. Furthermore, the ceramic is smooth, so bacteria stand no chance of impregnating its surface. This lessens the possibility of decay and gum disease. Also, there is no strange metallic taste or electric current effect, which can be created when two different metals are located in neighbouring teeth. The CEREC ceramic is also compatible with
mouth tissues.

Although ceramic fillings are gaining popularity for their advantages over the other types of fillings, it is still best to consult your dentist about the method that is most suitable for you.