Amalgam, Politicians, and All the Pink Trees

Let's play a little game.  Please think of a technology that has significantly bettered our lives, that we still use today, and that was first developed before 1830.

Yes, that's an "eight" in the second digit there.

Not easy, is it?

The telegraph?  First message: May 24, 1844.  Railroads?  The very first, the Stockton & Darlington in England, dates to 1825 so that's a candidate.  But railroads didn't start to get really useful until the 1840's- since there had to actually be enough of them to connect stuff!  Indoor plumbing?  Pretty much 1840's in America, and it took until the 1930's to reach many rural areas.  Electric lighting?  1879, by Edison of course.

And yet- dental amalgam, the dental restorative material made by "cold alloying" silver, mercury and other metals, predates them all.  There are indications that dental amalgam was used in the first part  of the T'ang Dynasty in China (618-907 A.D.), and in Germany by Dr. Strockerus in about 1528.  Certainly we know that dental amalgams were developed and placed into widespread use in France in the 1820's. We have documentation that dental amalgam was made by M. Taveau of Paris in 1826 as he introduced a mixture of silver coin filings mixed with an excess of mercury which was afterwards squeezed out. The technology was then brought to America in 1833 by the Crawcour brothers, two Frenchmen whose marketing skills were on the level of P.T. Barnum.  (And whose name sounds a bit like a restaurant entree that you'd encounter in New Orleans...)  The Crawcour sibs called their material "Royal Mineral Succedaneum" and engaged in aggresive and blatant advertising; they also often left cavities in the teeth that they filled.  These actions brought down upon them the wrath of the most prominent members of the dental profession in America. 

In these early years, long before the formation of the American Dental Association and indeed even formal university-based dental schools, (that was 1840), gold foil was the "gold standard" for restoring teeth.  If placed with a great deal of care it provides an excellent seal against the tooth into which it is placed, and being a noble metal it does not corrode in the presence of saliva.  Gold also happens to wear down in response to chewing over the years at precisely the same rate as tooth enamel.

As we find today, there were economic considerations involved in providing dental care at affordable fees.  Gold itself and the technique in placing it was very costly, and so silver amalgam became popular as a lower-cost alternative.  Two factions soon established themselves and the infamous "Amalgam Wars" of the 1840's resulted.  And yes, there ended up being actual barroom brawls among dentists over this issue...

Dental amalgam persisted and in fact did an admirable job of restoring countless American teeth for well over a century.  It has a faster wear rate than tooth enamel, but this rate is still within an acceptable range.  It seals by corrosion and modern formulations reach the best seal at the 2 year point, yet remain fairly well sealed for long after that.  Dental amalgam has of course been upgraded as technology improved.  The most significant change was in the 1970's.  Amalgam v2.0 kept the silver and mercury but took the tin out and replaced it with copper, resulting in less expansion while in service in a tooth.  Premeasured mixing capsules eliminated the variation in ingredients that leads to poor quality product.  Advancements in control of the particle size were made in the late 1980's.

The big issue has, of course, always been the mercury.  The phrase "Mad as a Hatter" famously derived from actual hatmaking; the process of making felt involved vast amounts of "quicksilver" and, in the days before OSHA, workers were exposed to high levels of this substance; among the effects of mercury toxicity are severe neurological problems.

Decades of countless studies though have consistently failed to find any health risk from dental amalgam restorations in the human mouth.  Perhaps the bottom line is this: although a small amount of elemental mercury vapor is indeed blown off the surface of a filling as a person chews, one's daily exposure from this source is approximately 1/100th of what we are absorbing from air, water, and certain foods in our modern society.  The power industry in particular releases a great deal of mercury vapor into the air at coal-fired power plants... 

The point which this author wishes to make is that science has advanced to the point where we have far better alternatives to this essentially ancient material.  In 1955 Michael Buonocore DDS (my personal dental hero) was the first human being to bond or adhere a restorative material to the enamel, or outside, of a tooth.  Bonding to the dentin, the inner, bone-like part of teeth, was much more difficult.  It was, however, accomplished in 1985 independently by Takeo Fusayama and John Gwinnett.  Advancements have occurred at a furious pace and the current bonding agent which we use in our office, Prelude SE, is so impressive that sometimes I personally feel like it's magic.  (The numbers are there in the research to back this feeling up with hard data.)  The composite resin filling materials that we bond into place with these agents have also advanced tremendously in the last two decades.

Cast and/or direct gold, porcelains of up to 7 different varieties, adhesive composite resins- all are shown by the science to outperform dental amalgam in wear rates, seal against future decay, many other parameters- if they are done properly with attention to detail.  They are, in fact, technique sensitive.  Here is an aerial view of some composite resins and porcelains that have been in flawless service for over ten years:

 

So- bottom line- dental amalgam is absolutely safe, so far as current science can tell us.  Current science also tells us that we have incredible advances in restorative materials since 1833.  Because of the scientific evidence of the superiority of the more modern methods of restoring teeth, we have not placed an amalgam restoration in our practice in over 15 years. 

There are however groups of hard-core "anti-amalgamists" out there who will do almost anything to advance their cause.  In our phair city of Philadelphia, they seem to have gotten to Councilwoman Blondell Reynolds Brown:

Hey, I wonder exactly what metals those earrings are made of?

Politics is certainly not science, and Ms. Brown has caused to be passed, in the City of Philadelphia, an ordinance requiring every dentist to review a "fact sheet" about dental amalgam with each and every patient- even if said dentist does not currently place amalgam restorations.

Edward R. Murrow comes to mind: "Oh, the humanity..."

Or, in this case, "Oh, the pink trees..."

Because, as you can see here, we use pink paper to readily identify in our charts which patients have and have not signed this required-by-law document; as if the paperwork in the medical realm isn't overwhelming enough already...

Comments

[Tom Bentley]

Rick, I think you have more than the amateur historian in you—excellent and engaging work on the history behind amalgams and their cousins, and a lovely treatment of the absurd at the end. Good worKk

[Tom Bentley]

And when I say, "Good worKk" I really mean it.

[jake]

You probably think fluoride is okay too

[Rick Wilson DMD]

Of course I 'think fluoride is ok too.' Fluoride occurs all over the planet in natural water supplies, in variable concentrations of between 0 (meaning trace amounts) and 7 parts per million. It was discovered in the 1940's that in concentrations of near 7ppm the decay rates of human teeth were minimal but the teeth were darker than average. 1ppm seems to be optimal.

But to say that fluoride is not ok is akin to saying that sodium chloride (common salt) is not ok, or calcium is not ok, or indeed oxygen is not ok. It's a mineral, naturally occurring, and not distributed evenly.