The majority of today’s patients will choose white fillings over silver. The reason for that is the mercury in the amalgam is often viewed as potentially toxic and cause sensitivity. Depending on which tissue it settles in, it will differ from one person to another. The suggested answer is that mercury from fillings doesn 't cause a specific disease. It causes poisoning, and a very small number of people are allergic to metals in the amalgam and may need to have another type of treatment.
In the 1990’s and 2000’s, composites were highly improved and are said to have a compression strength sufficient for use in the posterior teeth. It can also be used for anterior teeth that have been stained or that have some erosion. When getting a composite filling it can typically be smaller than the shape when receiving an amalgam filling conserving you more tooth structure. When a composite is placed, the bond or glue is placed into the cavity preparation first. This acts to glue the composite filling to the tooth, essentially splinting the tooth together. Amalgam just fills up the hole and doesn 't attach to anything.
As a result, the tooth stretches around the amalgam during chewing, causing small cracks that with time can cause breakage within the tooth or even decay. Decay that is left untreated can progress to infect the dental pulp and may cause an abscessed tooth. If the decay is too large, dentists recommend crowns over fillings. Composite fillings are also repairable. Amalgam fillings aren 't. If a composite chips, the same bond, as mentioned before, can cement the new composite to the older composite, creating a unified filling. Whereas amalgam needs to be removed completely.
When removing amalgam fillings it exposes you to mercury vapor released during the removal process. Teeth grinding may cause the release of high mercury vapor and mercury ions. A down side to removing
References: http://www.ada.org/sections/newsAndEvents/pdfs/safety.pdf JADA, Vol. 129, April 1998 501 http://www.ada.org/sections/publicResources/pdfs/dental_fillings_facts_full.pdf Craig 's Restorative Dental Materials (12th Edition) by John M. Powers and Ronald L. Sakaguchi CV Mosby, Feb. 2006