Mead Family Dental

Silver fillings: "tooth-saving work horse" or pure evil?

What's the deal with silver fillings? Why is it that we see news stories every once in awhile questioning the safety of dental amalgam? The answer, in a nutshell, is Mercury.

The element Mercury (Hg) is highly toxic. Think broken thermometers and fluorescent light bulbs. Avoiding Mercury exposure is highly recommended. As an element, Mercury is poisonous.

Another element, Chlorine (Cl), is also highly toxic. Yet, when combined with the element Sodium (Na) you get a chemical that is common, safe and in reasonable doses, delicious. Common table salt is a chemical compound called Sodium chloride (NaCl) and is perfectly safe to eat in moderate amounts. But no one in their right mind would go out of their way to ingest Sodium or Chlorine on their own. The same goes for Mercury.

"Silver fillings" aren't really fillings made of Silver. They are a combination of Mercury, Silver, Copper, Tin and other trace metals. Silver fillings are placed by thoroughly mixing these ingredients. The ingredients mix and form an alloy of the metals. This alloy is different than any of the ingredients individually. In other words, there isn't just Mercury, Silver, Tin or Copper in there. It's a whole new chemical compound made up of all of these metals. It's kind of like concrete. You start with cement, sand, stone and water. The final product is concrete. You can't go back and take the ingredients out of concrete without breaking down the concrete chemically.

The bottom line is that there's no such thing as "Mercury fillings." Dental amalgam has Mercury in it that is chemically combined with other metals to form an alloy. One of the properties of Mercury is it's ability to form an alloy like this at room temperature.

Can dental amalgam "leak" Mercury? Yes. There can be a very slight release of mercury from amalgam fillings. A study conducted by measuring the Mercury vapor levels inside the mouth over a 24-hour period in patients with at least nine amalgam restorations showed the average daily dose of inhaled mercury vapor was 1.7 µg (micrograms), which is approximately only 1% of the threshold limit value of 300 to 500 µg/day established by the World Health Organization. So there is Mercury released from fillings, but it's a very tiny amount.

What about Mercury exposure from dental amalgams causing diseases? The American Dental Association has weighed in regarding the safety and efficacy of dental amalgam. Scientific evidence concludes that the use of dental amalgam is safe. There is no evidence to support removing silver fillings in an effort to cure or prevent other diseases.

Dental amalgam has undoubtedly saved millions of teeth in its 100+ years of use. Until relatively recently there haven't been inexpensive options to restore teeth that could hold a candle to silver fillings. They're durable as heck and they're relatively easy and inexpensive to place.

Are there any problems with dental amalgam? I actually see two.

1. They're ugly. When polished they can be shiny and smooth, but they don't look like a tooth. They look like metal, which they are.
2. In order to place a silver filling you need to remove a lot of tooth structure. In a tooth that's never been filled before, this means that you're cutting away more tooth structure than you need to. 

To me, those are the main down sides to using dental amalgam. Perhaps these down sides deserve their own post (stay tuned!) I place very few dental amalgams any more because I'm confident that I can place an excellent bonded resin restoration (a.k.a: composite) in any situation that I might have used amalgam.

But my reasons for using composite fillings has nothing to do with Mercury. In my mind, the Mercury is a non-issue.

Do you have questions or comments about this post? Can this Saginaw dentist be of service to you in any way? I'd love to hear from you at my email: alan@meadfamilydental.com. Or give us a call at the office at (989) 799-9133! We'd love to be your Saginaw dentist! And don't forget to "like" us on Facebook!

 

pH, your body and your mouth

I recently bought a bottle of water at Walgreen.  The brand was "Iceland Pure Spring Water" and it featured "pH 8.88" prominently on the label.  I read a little further to find:

"...it has one of the naturally lowest mineral contents of any water and a high pH of 8.88.  Icelanders live longer than any other nationality; we believe their secret to long life is their water."

This is an interesting claim.  My research (if you want to call finding a cool chart Wikipedia chart research) shows Iceland coming in 3rd to Japan and Hong Kong.  FYI...the U.S. comes in tied for 36th place with Cuba and Denmark.  So the claim that Icelanders live the longest is in dispute, but what about the pH of their amazing spring water?  Could it account for longevity?  Should I be worried about my pH?

pH is a measurement of acidiy or alkalinity in an aqueous (water based) solution.  A solution that is high in acidity has a low pH and a solution that is more alkaline has a higher pH.  pH is measured on a 14 point scale with 0 being the lowest pH (most acidic) and 14 being the highest pH (most basic or alkaline).  A pH of 7 is considered neutral, neither majority acid or alkaline. This 14 point scale is logarithmic, which means that each number on the scale is 10 times higher or lower than number above it or below it.  For instance, a substance with a pH of 3 is 10 times more acidic than a substance with a pH of 4 and 100 times more acidic than something with a pH of 5.

The pH of the human body is variable depending on the part of the body you're talking about.  The stomach has a pH of about 1...very acidic.  This is useful in breaking down the food into smaller, more digestible pieces.  Lysosomes, the small bags of chemicals found inside cells are used to break down damaged cell parts.  They can have a pH of 4-4.5.  Our blood is at a relatively steady pH of 7.34-7.45. The body keeps the pH of our tissues relatively constant completely separate from our diet.  

Our mouths are a bit of an exception.  The pH can range quite significantly in our mouths due to the presence of acid producing bacteria.  Some of the bacteria in our mouths can turn the carbohydrates that we eat into acid.  I've talked quite a bit about this in previous posts.  This acid can dissolve the surface of the tooth if it reaches a critical pH.  The critical pH, or the pH at which tooth structure begins to dissolve is 6.7 on the root surface of the tooth and 5.2 on the enamel.  Diet, habits and saliva flow have a lot to do with how well an individual defends against pH drops in the mouth.  But these localized oral pH fluctuations are not the same as pH change of the body.  

 You often hear claims that the pH of your body being off or unbalanced are the cause of disease.  Whether these claims are indirect like my water bottle or more direct as in some blogs or books, they need to be looked at critically.  Most of these claims have no basis in science or actual physiology.  Beware of diets or claims that talk about "changing your body pH."  Often they direct you to test your saliva to evaluate your body's pH.  That would be akin to checking the inside of your furnace to evaluate what the temperature of your house is!  Your body has very specific control mechanisms for regulating your pH through the lungs and kidneys.  Your diet makes no difference with regard to your body's pH, except in your mouth!

Some disease states can result in pH changes.  Diabetics can experience diabetic ketoacidosis, which can lower the pH of the blood.  This is a consequence of their inability to use sugar in their bodies. However, in healthy individuals this is not a concern.

So, do I think my Iceland Pure Spring Water at a pH of 8.88 will prolong my life?  Not really.  However, it was cold and delicious and made it so I wasn't so thirsty.   So it did what I was hoping it would!

Do you have comments or questions about this or any of my other posts?  Do you like what you see on my blog?  Leave a comment here on the blog or feel free to email me at alan@meadfamilydental.com.  This Saginaw dentist writes all the posts and answers his own email.  Thanks for taking the time to read!