OUR THOUGHTS ON AMALGAM

Chances are you have heard of the controversy surrounding mercury-silver filling or amalgams the past few years.

The primary reasons for this controversy is based on the research that showed that mercury is released in the mouth while chewing. Other studies have shown that the presence of mercury fillings can cause an increase in mercury level in the brain and other vital organs. This is important because Mercury is a very toxic poison and only a slight increase in the Mercury level in body tissues should warrant a concern.

Some people claim that mercury in your teeth can lead to allergic reactions or other more serious health problems. Some countries have gone so far as to ban dentists from using amalgam fillings.

So what are the facts?

Amalgam fillings consist of approximately 50% mercury, the rest being made up of silver, zinc and copper. And while it is undeniably true that mercury vapours are released from these fillings and scientists agree that mercury absorbed in high enough doses cause health problems, studies have been inconclusive about how much of the amalgam fillings mercury is actually absorbed by the body and how much would have to be absorbed to cause any problems.

However we do know that there is a direct correlation between the number of amalgam fillings in the mouth and the levels of mercury in body tissues.

Furthermore, studies show that after 20 years there is no more mercury left in the fillings. Where has it gone?

My personal position is that I no longer recommend or use mercury fillings.

Whilst the jury may be out on the issue of mercury release and health issues there are many other reasons why amalgams are a compromise filling material. My recommendations are based on physical properties, strength and the effects amalgam has on healthy tooth structures. If we look at how amalgams work we can see why. When saliva contacts an amalgam, a corrosion product is formed which inhibits decay. Because amalgams are not retentive in their own right they must be wedged in position and use undercuts so they do not fall out.

Over the years the amalgams act much the same as a thermometer, expanding and contracting with variations in temperature until eventually the amalgam appears to be “growing out of the tooth” Additionally, small amounts of mercury leak out and the amalgam filling begins to crack at the edges and leakage occurs where the filling meets the tooth

When too much leaking occurs, the tooth decays and the fillings or tooth begins to break. If the patient waits too long, the excessive leaking may cause severe decay and lead to a root canal or a tooth breaking apart.

Amalgam (Silver) Restoration		Composite Restoration
Undercutting - standard procedure Chewing pressure can open margin between tooth and restoration Expansion of filling Cusps weakened Tooth fractures		No undercutting Composite bonded (cemented) to tooth Strengthens tooth

Today we have newer materials and techniques that not only strengthen the tooth but are also much more dimensionally stable and cosmetic.

Below are just a few of the many reasons besides mercury release, that we feel amalgam is an inferior filling material and bonded restorations are far better.

1. Amalgam is ugly!

No one in their right mind really wants a dark black or grey filling in their white tooth and that is exactly what amalgam looks like. Not only does it cause the tooth to appear grey from the front; it also stains teeth so that in the future, healthier tooth structure may have to be removed to restore the tooth to its more natural appearance.

2. Amalgams break teeth!

Amalgam fillings expand upon setting and continue to expand and contract at a much different rate from tooth structure causing the teeth to crack and break. This usually results in a fractured cusp and consequently a much larger filling is required on that tooth. Often the only way a tooth can be strengthened is to place a crown, which could have been avoided if a better filling material was used in the first place.

3. Amalgams weaken teeth!

Because amalgams do not bond well to teeth and invariable are wedged in position a tooth restored with amalgam is only 1/2 to 1/3 as strong as an unfilled tooth.

4. Amalgam fillings leak, causing recurrent decay!

Because amalgams do not bond to teeth structure there is a gap between the filling and the tooth. This gap provides a pathway for bacteria and acids to get into the dentine and cause further decay. Left unattended this decay will continues to destroy healthy tooth structure. Since Amalgams stain the tooth dark, often signs of microleakage are undetectable. Studies show that there is decay under at least 50% of amalgams.

5. Amalgams have lower wear resistance than correctly placed composite resin fillings.

The key words here are “correctly placed”. Studies have shown that new resin materials wear better than amalgams, and should last longer than amalgams. Bonded porcelain inlays are even better again.

6. Amalgam manufacturers are becoming wary!

A major manufacturer of amalgams, The Caulk Company, has recently begun cautioning against placement of amalgams in pregnant and nursing mothers, children under the age of seven and people with kidney disease.

7. Amalgam is a treatment compromise

And we only recommend to you what is best for your dental health and what we provide for our families and ourselves.

Today there are better materials available without the potential risks. The truth is nobody can tell you for sure whether mercury amalgam fillings will affect your health. But we can tell you this for sure, bonded fillings don’t release vapour of any kind, they don’t leak, are more durable, they strengthen your teeth and they look great too.

Before

After