There has been a lot of controversy over the use of amalgam fillings due to the fact they contain low levels of liquid mercury. In the past these fillings have been used to fill cavities in the back teeth, or in areas which aren’t highly visible. During chewing, small amounts of mercury vapor1 are released, as well as during the placement and removal of amalgam fillings, but these levels are insignificant and harmless. In 2009 the FDA ruled that amalgam fillings weren’t harmful, although they are classified as being a Class II device which is deemed to be a moderate risk, as opposed to a Class I device which carries a lower risk level.
The agency looked at long-term clinical studies in both adults and children aged six years and older with have dental amalgam fillings, and identified no causal links between the fillings and adverse health effects. The FDA has warned against the use of amalgam fillings in children under the age of six, and in pregnant women, but hasn’t prohibited its use. The American Dental Association doesn’t have any restrictions over the use of dental amalgam.
Although amalgam fillings are hard wearing,2 and are an affordable alternative for back teeth, they are becoming less and less widely used, and some dentists have stopped offering them altogether. More people choose to have old amalgams replaced with alternative types of fillings. A huge disadvantage of having an amalgam filling is that a larger amount of healthy to structure must be removed to ensure the cavity is large enough for the amalgam filling. Amalgams also expand and contract when coming into contact with hot and cold liquids, and this can cause the teeth to fracture over time.
A lot of modern dental materials can create a far better esthetic appearance, and are preferred by most patients, especially as the emphasis these days is on having a white smile. So what exactly are your choices other than amalgam?
Gold fillings are a good alternative to amalgam for repairing cavities in the back teeth. They are extremely durable and are able to withstand chewing forces. A gold filling can be much more aesthetically pleasing than a silver colored amalgam filling. However they are more expensive than other materials, and will always be visible in the mouth. Gold fillings will need at least two dental visits, as the tooth has to be prepared, and an impression taken and sent to the dental laboratory. The gold filling is cast to exactly fit the cavity before being polished and returned to the dentist for fitting and cementing.
Composite fillings are made out of a type of tooth colored resin which is closely matched to the patient’s natural teeth. Composites are ideal for repairing visible signs of decay or damage to teeth, and as they chemically bond with the tooth they provide additional support. Composite is a very versatile material, and can be used to repair worn teeth, as well as teeth which have become decayed or chipped. In addition less healthy to structure must be removed in order to prepare the tooth to receive the filling.
The major disadvantage of composite fillings is their lack of durability, as they need replacing after around five years or so, and are less able to withstand substantial chewing pressure. They are not so suitable for large cavities in back teeth. They are also quite susceptible towards staining.
Ceramic fillings are made entirely out of porcelain, and modern materials can be extremely strong. They are more resistant to staining than composite material, but can be quite expensive. These types of fillings are made in the dental laboratory and require at least two visits to the dental office, but they can last 15 years or even longer, and are ideal for filling larger cavities in back teeth.
Glass Ionomer Fillings
Glass ionomer fillings are made out of a combination of acrylic and glass material, and are generally used for fillings around the gum line. They are weaker than composite fillings, and will generally only last a few years.
Inlays and onlays
Inlays and onlays are used to replace larger areas of decay. An inlay replaces the central chewing area of a back tooth whereas an onlay can be used to partially replace some of this central area as well as the cusps of the tooth. The cusps are the part of the tooth which is slightly raised from the chewing area, and all located on the inner and outer edges of the tooth. Inlays and onlays can be made out of composite, porcelain or gold.
Inlays and onlays can be direct or indirect. If they are direct it means they can be constructed in the dental office, and can be placed in one visit. If they are indirect then the dentist will need to take impressions, and the process is very similar to that for ceramic fillings and gold fillings in that they are made in a dental laboratory.
The type of filling you choose can depend on budget and the tooth being filled. Your dentist is likely to advise you on the best choices available to you.
- 1. Berglund A, Molin M. Mercury vapor release form dental amalgam in patients with syptoms allegedly caused by amalgam fillings.Eur J Oral Sci. 1996; 104:56-63
- 2. Frank AL, Glick DH, Patterson SS, Weine FS. Long term evaluation of surgically placed amalgam filllings.Journal of Endodontics. 119; 18:391-398