Composite vs. Amalgam

Composite vs. Amalgam

Amalgam fillings are silver fillings you may have or seen in other people’s teeth.  It was invented in 1819 and is mercury based.  It has been thought that mercury poisoning was caused by amalgam.  In 1957 it was discovered that once saliva covers the amalgam, the mercury is no longer released.  Eventually the danger of mercury came up again in 1972 and has been studied consistently with correlations of amalgam and mercury.  In 1993 the largest German manufacturer discontinued production of amalgam, in 1994 Sweden stopped using amalgams in pregnant women and children and in 1995 Canada made guidelines for dentists discouraging the use of amalgam fillings in pregnant women, children, people with kidney disorders and other vulnerable people. In 2008 the FDA claimed that no science exists on safety of dental amalgams and dentists continue to use them today.

Amalgam has been used as a dental restoration for more than 165 years.  Despite controversies over the years, amalgam lasts a long time, does not cause sensitivity after placement and has a self sealing property.  Amalgam is composed of silver, tin and copper. It may also include indium, palladium, and zinc.

This photo shows cusp covering.

Composite, or tooth colored fillings were introduced in the 1970’s.  They have similar longevity to amalgam and aesthetics is much more accepetable.  It a plastic or glass mixture that can be used to fill decayed areas, reshape distorted teeth, and provide tooth colored matches.

Advantages of composite fillings include:

• Aesthetics
• Bonds well to the tooth structure
• More conservative
• Can repair chipped, broken or worn teeth
• Repairable- can just add to composite if chipping occurs around the composite
• No mercury controversy
• No corrosion

Placement and type of composite used can avoid disadvantages such as chipping, shrinkage, and durability. Other disadvantages include keeping the tooth dry (free of blood and saliva) and time and expense–it can take up to 20 minutes longer to place a composite.  Fees are increased and some insurance only covers a portion of a front tooth composite and potentially none of a back tooth.  Failures of composite include decay around the filling or fracture from patient behavior like clenching and grinding or poor dental health.

In conclusion, as new, stronger and more esthetic products are found, amalgam may diminish completely, but not due to health concerns. At this point, amalgam holds up better than composite if they area is large in size or involves the covering of a cusp.  Depending on location in the mouth, area being addressed and technique used, the dentist will best be able to determine if amalgam or composite is the best choice.