Amalgam Fillings Vs White Fillings


AMALGAMS (Silver),

COMPOSITE (white),

GLASS IONOMER (GIC’s, white) and



What is a “Silver Amalgam?

Amalgam is a mixture of metals, that dentists use for fillings, particularly back teeth. It is made of silver, copper, tin, and mercury.
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What are the benefits of amalgam?

It is incredibly strong, has excellent longevity, and when it fails, is usually easy to repair, usually by doing another amalgam. One of the best things about amalgam is that it does not matter if a filling gets wet with saliva, water, or blood when it is done. The result will still be excellent, and long lasting. This is very important when working on a back tooth, along the gum line. Amalgams are very resistant to future decay. It is thought that the bacteria that cause decay just hate some of the metallic ions, and do not progress as well. They are not very often sensitive after they are placed. Technically, they are relatively easy, and have a good safety margin ie- the filling getting wet, an uncooperative child, an adult who cannot open properly for a long period of time. It is usually very easy to get a good contact between two adjacent fillings, so food impaction is minimal.

In the short term, they are the cheapest option.

In the long term, they are by far the cheapest option, as amalgam fillings typically last significantly longer than composite fillings.
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Do amalgams split teeth?

Often, it is said that amalgams split teeth. I do not believe that this is the case. It is simply that whenever you put any filling in a tooth (be it composite, amalgam, porcelain or GIC), the tooth is inherently weaker than what the tooth was originally.
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What are the disadvantages of amalgam fillings?

It is not pretty! This is by far the number one complaint against it. Yes, it is the ugly duckling in terms of dental materials. Amalgams do not resist acid wear at all.

Some people, particularly some alternative health practitioners have suggested that amalgams may be detrimental to health. In all the reputable studies done, there is no difference in the health of people with and without amalgams in their mouths. Some unscrupulous dentists suggest that all amalgams should be replaced with cerecs or crowns at $1000-1800 per tooth.
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What is a composite material?

Composite resins are mixture of powedered glass and plastic resin. They are significantly weaker than amalgam. They adhere to the outside of the tooth (the enamel) very, very well. They do not really stick to dentine over the long term, with often catastrophic results.
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What are the good aspects of composites?

Aesthetically, composite is one of the best looking fillings (which is why everybody seems to want them). They have a consistency like Play-Dough, and are set hard with a blue light.
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What are the problems with composite materials?

One of the worst things about composite is that, if I get them wet when they are being done, they are absolutely hopeless. They do not bond, and this leads to staining, and decay. It is relatively common for me to see composites done a few short years ago, with gross decay under them.

Of all fillings, composites are the WORST in resisting future decay. There is no natural inbuilt physical property that minimises bacterial growth. When composites fail in back teeth, it usually much more difficult to repair them, and often a root treatment, crowns, and minor gum surgery is needed to restore them.

Composite fillings do not resist acid wear at all. They are technically more difficult to get an excellent result- a tiny amount of moisture will ruin an otherwise good filling.

It is much harder to get a good contact between two adjacent fillings, that can lead to food impaction happening.

Initial cost is higher. Why would a filling that lasts LESS and has MORE troubles than a silver one be more expensive?? Simply because of the time involved to get things as good as it can be. I will often place a rubber dam, use a laser along the gumline to allow myself the optimal result. Extra time simply increases the cost.

Long term cost of composites is significantly higher than silver amalgams. The failure rate of composites (which has been proven time and again in reputable dental journals) is much higher than amalgams. Composite is just an inferior material in terms of physical strength, and its more resistant to decay, leading to much higher failure rates.
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What about sensitivity?

Composites tend to have more sensitivity than amalgams. The reason is unclear, however, amalgam tends to self seal itself, via a minute expansion. Composite does the opposite, it tends to shrink, and pull itself away from the cavity walls. This contraction can be minimised, but not eliminated. Composite does not bond properly to dentine, which also leads to sensitivity.

What about GIC’s (Glass Ionomer Cements)?

These are excellent for adhering to enamel, and also dentine. Their main disadvantage is their weakness. They are just too weak for large fillings in back teeth.
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What are the benefits to GIC’s?

GICs have good aesthetic properties, they are white, but do not look quite as nice as composites. GICs are the most resistant fillings to decay than any other fillings bar none. They have an exchange of ions, which protects decay, and can actually repair the tooth at a microscopic level! They are excellent at minimising sensitivity in teeth. They tolerate some moisture when doing a filling. They are somewhere in between composite and amalgam in this respect.

They are also excellent at resisting acid wear. In an acidic mouth (ie coke drinker, stomach reflux, and the acid in every mouth for an hour after every meal), the saliva helps to bring the ph back to normal. However, something must dissolve! Usually, it is the teeth, over a very long period of time.

GIC fillings however, do dissolve preferentially to teeth. THIS IS VERY BENEFICIAL! Thus, they act like the ‘sacrificial anode’ on an outboard motor. Something has to dissolve, and it is better to be a filling, rather than the tooth.

I have placed many composite fillings in patients mouths, that were perfectly sculpted. Sometimes, after only four or five years, i can see and feel the tooth around the composite is no longer there, it has literaly dissolved. This means that there is active erosion and an acidic environment in the mouth

When GIC fillings are placed in similar situations, they seem to hold up better (though they dont look as nice), and in cases of severe acid problems, the filling can be seen dissolving, which is actually a beneficial act (as it saves the tooth from dissolving).
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What are the disadvantages of GIC’s?

They are very weak, particularly to occlusion (biting) stresses. They never look as nice as composites, but most patients will never be concerned, as they are still “white” They never feel as nice and smooth as composites. The tongue usually gets used to them after a week or so.
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What about Cerecs / Crowns?

A crown (can we get this as a link to the crown page) is usually the best way of restoring a badly broken down tooth. A CEREC is a partial crown, done in one visit. They are expensive (due to the machinery, software, and the time involved) I do not own a cerec machine. I have seen some very nice work done, and some not so nice as well. My main issue is that the porcelain that is used is nowhere near as strong as the new porcelains that can be done in a laboratory. Thus, in the case of a partial crown (or where other dentists would do a cerec), I would prepare the tooth, send a mould off to the laboratory, and cement a MUCH STRONGER porcelain filling in two weeks time.
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I’m confused, what materials should my fillings be?

I tend to use all of the above, where I feel they are best used.

I use a lot more GICs than most dentists, as I feel they are the most resistant to decay, and a significant proportion of people have gastric reflux (link for both words together, to our gastric reflux page) , and these fillings help them immensely. In front teeth, I use a combination of GICs and composite fillings. In side and back teeth, where the decay is either small, or on the outside of the tooth, I will usually use a GIC or a composite. In a side and back tooth, where the decay is moderate, or large, and particularly if it is a failed composite, or along the gum line, I will almost always suggest an amalgam. I feel very strongly about this, as in the short, medium and long term, a much better end result (apart from the aesthetics) will occur. Amalgams are certainly not perfect, nor do they last forever, I just feel that in back teeth that you cannot see, they are usually far and above better than the next option.
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I want all of my amalgams replaced, can you do that for me?

First one must consider if any NEED to be replaced, from decay or fractures.

I see many people who have been quoted thousands (in the case of composites), or tens of thousands of dollars (in the case of cerecs or crowns) to replace fillings that are inherently still functioning, and there is no need to replace them.

Please consider that I really do believe that if we do proceed, I will be charging you significant amounts of money, in order to replace something that does not need to be done, and not be as good as what you currently have!!

When I explain this to most males over the age of 30 that I charge less for an amalgam filling that is better and lasts longer than a white one, most are happy with leaving things as is.

Most ladies are a bit more conscious of their appearance, and often want to brighten things up a bit. Often in these cases, if we replace the visible ones, and leave the others as is, it is a good balance between aesthetics, and is much more cost effective.

There are lots of times when, in my opinion, an amalgam is the only real sensible option. For a badly broken down tooth, or one that has a fracture in it, or has had a root canal therapy usually a crown is usually the best option.
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