White vs Silver Fillings in back teeth

In this article, we are talking about the use of silver fillings in back teeth only (tooth colored materials are always used in front teeth).

Recent studies (2009)* are showing that silver (amalgam) fillings in back teeth are lasting twice as long as white, composite ones. So, why are white, composite fillings used at all in back teeth ?

  1.  Cosmetics – this is the # 1 reason
  2. Cracked teeth – Composite fillings can, in some cases, hold teeth together better.
  3.  Concerns with the safety of silver (by patients, not dentists). Thousands of studies by the American Dental Association, NIH, NE Journal of Medicine (just to name a few) have confirmed the safety of amalgam.
  4.   Everybody’s doing it

My practice philosophy is to use silver amalgam in back teeth except in cases of high visibility (usually upper molars and bicuspids), for cracked teeth, and when small areas are prepared with air abrasion. Tooth-colored fillings are always used for front teeth and areas of higher visibility.

One study actually found that white fillings may promote the growth of microorganisms. Silver has an anti-bacterial property (That’s why it’s being used in clothing for the military and in other “no-odor” clothing). This is an important factor for fillings in hard-to-clean areas such as in between back teeth. It’s also important in minimally flossing, junk food eating teenagers.

2/25/2013 -  We are seeing more and more failures of white fillings in back teeth. Composite (white) fillings require a high degree of home care – much higher than with silver amalgams. Brushing and flossing after every meal is just about manditory.

More Thoughts on Silver Amalgam:

Some people have questioned the safety of silver amalgam fillings because they contain mercury. The first thing I want to say is that I have silver amalgam fillings (in back teeth) in my own mouth, as do my wife and children. That should tell you something about my feelings as to the safety of amalgam.

When mercury is combined with silver and other metals that make up amalgam, it forms an inert substance. Inert means it doesn’t do much – it doesn’t break down, it doesn’t dissolve out – it just sits there in the place of decay in your tooth.

Are there alternate materials? Yes, gold has been and still is perhaps the best all around filling material for back teeth (see “Crowns & Bridges”. It is also expensive. Gold fillings cost about five times as much as silver filings of the same size. Direct (made on the spot) and indirect (laboratory made) composite resins (white fillings) or porcelain are available and are increasing in use. The direct composite is the most widely used material in place of silver amalgam.

Why not just use composite resins and be done with it? Well, there are several issues here. The first has to do with the fact that there is nothing wrong with amalgam. The second has to do with cost and insurance coverage. Composites cost more than comparable size amalgams – up to twice as much. Very few insurance companies will cover the additional cost of resins in back teeth. What they often do (but not always) is to make an allowance – they will cover the cost of the white restoration at the same level they would cover a silver amalgam. This translates to one half the cost or less when you include co-pay (even less if deductibles are involved). Insurance companies do cover most of the cost of composite resin fillings in front teeth (canines and incisors only) where silver amalgam would be unsightly.

Also, white resin fillings are much more technique sensitive than silver amalgams. This means that they can be more difficult and take longer (generally) to put in.

But, there are situations where white resins are so superior to amalgam that we are going to use them anyway – e.g. to fill cavities where air abrasion (drill-less dentistry) is used to remove decay; for teeth that have a lot of cracks in them (resins actually bond the tooth together); and for very deep fillings (resins are less apt to affect the nerve). These latter teeth usually will need to be crowned, eventually.

BTW – there have been studies that showed that tooth colored composite fillings can be estrogenic (give off estrogen or an estrogen precursor). Again, however, many studies have shows that these materials are safe.

MSNBC Article Sept 2010

By Linda Carrol | msnbc.com contributor

Caution for pregnant women – The article cautioned that pregnant women should wait whenever possible on dental procedures involving BPA-associated resins until after their babies are born because of the estrogen potential.

So, here it is – Amalgam detractors have been screaming for years for the use of white filling materials instead of “Mercury Amalgam” (a term used by them). What are they going to say now that the very material they have been advocating “shouldn’t be used on pregnant women until after their babies are born” according the the MSNBC article?

The answer: Both amalgam and composite filling materials are safe to use. There has been no properly conducted test that has shown any reason why either material cannot be safely used on anybody at anytime.

A site that has reliable data on the safety of amalgam is “The National Council Against Health Fraud” http://www.ncahf.org/ . A site on the safety of resins is: http://www.bisphenol-a.org/human/dental.html


* An Evaluation of Replacement Rates for Posterior Resin-Based Composite and Amalgam Restorations in U.S. Navy and Marine Corps Recruits John W. Simecek, Kim E. Diefenderfer, and Mark E. Cohen J Am Dent Assoc 2009; 140: 200-209 reports amalgams are lasting twice as long as composite.

Jul 29, 2009 | USA – FDA says mercury dental fillings not harmful by Reuters

WASHINGTON, DC, USA: The US Food and Drug Administration said silver-coloured dental fillings that contain mercury are safe for patients, reversing an earlier caution against their use in certain patients, including pregnant women and children.

Quotes from other references: “…composite restorations required seven time as many repairs as did amalgam restorations.” (The Longevity of Amalgam Versus Compomer/Composite Restorations in Posterior Primary and Primary Teeth: Finding from the New England Children’s Amalgam Trial – JA Soncini, et al., JADA 2007,138 (6):763-72

Risk of secondary caries (decay) was 3.5 times greater in the composite group. Conclusion: Amalgam restorations preformed better than did composite restorations…. (Survival and reasons for failure of Amalgam verses Composite Posterior Restorations Placed in a Randomized Clinical Trial.” – M Bernardo, et al., JADA 2007, 136 (6): 775-83

JADA = Journal of the America Dental Association

Posterior = back (e.g. molars and bicuspids)

restorations = fillings

NH law – RSA 317-A:17 (j) and the Code of Ethics, part 5.A. REPRESENTATION OF CARE, and based on current science, dentists shall not recommend or suggest the removal of amalgam fillings from the non-allergic patient for the alleged purpose of removing toxic substances from the body.

Nov 2011 JADA –“I have yet to find a dentist who can point to any scientific study showing the universal superiority of composite resin to amalgam. When science can demonstrate another material to be superior to amalgam for universal use in the general public, then state boards logically would endorse the new material. (But) Until then….”           

-  Neil Hiltunen DMD, President NH Board of Dental Examiners




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