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These days we can synthesize gem-quality diamonds that have fewer defects than natural diamonds. See the link. Sometimes they are called "cultured diamonds". In theory they should also be less expensive than natural diamonds, but in practice, as long as the price of natural diamonds is high, and few
companies are in the cultured-diamond business, synthetic diamonds can be sold for almost as much as the naturals.
Eventually, of course, competition will increase and prices will come down. When that happens, and you need to go to the dentist to deal with, say, a broken tooth, your dentist will be able to offer you a Diamond Tooth. An appropriate sized cultured diamond will be carved with an appropriate laser or ion beam, into the shape of an implantable replacement tooth.
They already have the technology to ensure that a replacement tooth on, say, the upper jaw, properly matches and intermeshes with the associated tooth on the lower jaw, so this is just a matter of carving a diamond into the shape that is currently applied to some other substance, from which they currently make replacement teeth.
A Diamond Tooth, of course, will be impervious to food acids and bacterial decay. And if you had a mouth full of them, especially at today's prices, you could quite truthfully say you had a million-dollar smile.
Synthesized gem-quality diamonds
http://gemesis.com/education/lab-created/
As mentioned in the main text. [Vernon, Sep 27 2012]
Huge Diamond Deposits Revealed In Russia
http://slashdot.org.../17/2123255_1.shtml
(In the news) [Sep 18] [Inyuki, Sep 27 2012]
Diamond Anvil Cell
http://en.wikipedia.../Diamond_anvil_cell
Diamonds can withstand considerable pressure. [Vernon, Sep 28 2012]
[link]
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Diamond's tendency to shatter on impact may not make it the best for this. |
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// competition will increase and prices will come down ... And if you had a mouth full of them, especially at today's prices, you could quite truthfully say you had a million-dollar smile. // |
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You are therefore asserting that the second part is Baked, which it isn't, as the first part (large diamonds at costs economically competitive with silicon-based components) is not yet feasible. |
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[MechE], when do teeth normally experience such impacts, more than, say, diamonds on rings might experience when dropped? I know diamonds are brittle, but THAT brittle? |
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[8th of 7], the prhase "million dollar smile" has existed for a long time, independent from most dental work. All I was saying was if this Idea was implemented today, then the phrase could become literally true. Obviously, in the future, with lower diamond prices, it wouln't be literally true. (You could still have a "flashy" smile, though. :) |
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The ultimate bling-bling. |
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There might be a concern about thermal
conductivity, however. The conductivity of a human
tooth is (apparently) on the order of 0.0065
W/(cm*K), whereas natural diamond reportedly
conducts at up to 22 W/(cm*K). Sipping hot coffee or
eating ice cream could prove excruciating. |
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These exist in fiction: Terry Pratchett's trolls have diamond
teeth, which hold both monetary and masticational value
(but good luck trying to steal them). |
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For reasons already mentioned diamonds are a horrible
material for teeth. However diamond caps on regular
teeth would be awesome if properly layered with an
energy-absorbent material. |
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This could end badly unless opposed teeth are
diamonded. Otherwise the diamond tooth would
quickly wear away the natural one. |
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I also suspect that diamond teeth would be at least
as tartar-prone as natural ones, and their
transparency would draw attention to this. |
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Of course I could be wrong, but obviously that would
be very unlikely. |
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I remember reading something about a process for coating
hard surfaces with a thin layer of synthetic diamond, but I
can't remember if it was real tech, wishful thinking, or
pure fiction. Anybody else know what I'm thinking of? |
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I honestly don't know if the impact or bite force would be enough to shatter diamond but I suspect bite force might. A lot would depend on the nature of the diamond and whether it could be constructed specifically so that lines of cleavage were not in line with normal loading. |
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The main point, though, is that if a normal filling shatters, it's no big deal. If a diamond filling shatters, the shards would be unpleasant at best. |
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//coating hard surfaces with a thin layer of synthetic
diamond// but the tooth (or false tooth)
underneath it would flex, leaving the diamond layer
prone to breaking. |
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[Alter] It's either chemical vapor deposition diamond coating or diamond like carbon, both of which can be used as industrial coatings. Diamond is expensive, brittle, and polycrystalline (neither clear nor as hard as mono-crystalline diamond). DLC is amorphous carbon, cheaper and more flexible, but not quite as durable. I doubt either could be applied to teeth, as they both require high temperatures. |
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So, it all comes down to Joules per mol per jewels per molar as per Jules [Vernon]... |
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You guys are harsh. Vernon, I probably cant afford
the full set but would be happy with some
rubberised Cubic zirconia or perhaps a titanium
carbide set of gnashers if I want to push the boat
out. |
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I seriously doubt there will be any shattering of
teeth. |
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I once bit a radiator while playing peekabo and
surprisingly got away with minimal damage, which
considering the force involved was remarkable. |
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Jules Vernon, as in "Journey to the Centre of the Tooth", "Twenty Thousand Fillings under the Sea" and "From the Lips to the Gums" ... ? |
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... Jules Vernon's "The Varnished Diamond" or "Clovis
Dar-dentine" |
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Okay, best information I can find (which is not very good) says diamonds can shatter under as little as 2 MPa, ~290 PSI. Human bite pressure is only ~120 PSI. If that's true, it would be safe enough, but I'm still not convinced you wouldn't have problems if the bite pressure happened to align along a normal cleavage plane. Not shattering, just splitting. |
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I'm voting nanotube impregnated stainless steel with a
saphire coating. |
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As for plaque you could scrub as hard as you want with a
toothbrush as long as you don't do the gums... |
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//best information I can find ... says diamonds can
shatter under as little as 2 MPa// |
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You're right about that information not being very
good. Is that tensile stress or compressive? If it's
compressive, then it's wrong. In fact any figure
for the compressive strength of any material is
wrong.
Compressive strength depends hugely on
geometry. |
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An inch-diameter pillar of wood, one inch tall, will
support several hundred pounds of compression.
An inch diameter pillar of wood twenty feet tall
will fail by bowing and folding. Compressive
strength is hugely geometry dependent; tensile
strength less so. |
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Yay, cement dentures. Eat your food the Blue
Circle way. No need to clean, just throw 'em
away and pop in another set. So what if your
teeth are a dull grey colour? It's never
bothered Mitt Romney … |
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[MB] Ultimate compressive strength is not
dependent on geometry. I admit ultimate
compressive load is, since for ductile materials,
the tendency to become shorter but with a larger
cross section under load makes them stronger.
Since diamond is very brittle, I wouldn't expect
that to be a problem here. |
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Of course a compressively loaded structure can
fail in other modes, as you describe, but if you
can find a diamond with a narrow enough aspect
ratio to fail in buckling, I'll be surprised. |
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So that once the future archelogists unearth a crystal skull with diamond teeth, they know that we had the technology to make it? |
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//Ultimate compressive strength is not
dependent on geometry.// Tis so. A gapless
material cannot "fail" by pure compression (you
can't make a crack in something by pushing its
atoms closer together); the closest it can get is
plastic deformation (ie, squeezing out sideways). |
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Diamond will only break by tension. A
compressive load can generate local tensions, but
the size of these tensions will depend not only on
the compressive force applied, but also very much
on the geometry. (Extreme case - make a U-
shaped diamond and squeeze the ends together;
the diamond will crack in tension at the base of
the U.) |
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If I'm wrong, explain to me how a crack can form in
a diamond by pushing the atoms closer together. |
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Even if it is failure in tension on a microscale (it's
not, a lot of shear
going on as well), the loading is purely compression,
and it's relatively consistent for a given material.
Not as consistent as tension, I admit, but even
tensions is highly vulnerable to defects in the
material. |
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I will agree that the thermal conductivity problem puts a big dent in this Idea. Perhaps a solution can be found in the way a Diamond Tooth is attached to the bone. That is, perhaps a suitable thermal insulator can be included. |
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[21Quest], the main text plainly states that the diamond has to be carved into the appropriate shape, to match the opposing tooth (whether also diamond, or natural). I suggested ion beams as a possible method for doing that. Lasers would probably work not-so-well for the carving task, because diamond is quite transparent, including to many UV frequencies. |
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You're thinking of graphite. Diamond is
tetrahedral. And while on an atomic scale the
cleavage planes are important, on the macro
scale of a synthetic tooth the approximation
of a curve by a sequence of linear facets is
perfectly acceptable. |
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Carbon atoms are nanometres in diameter;
teeth are millimetres across. There's at least
six orders of magnitude difference in the
scale of the features. |
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//can a crystalline structure BE carved into a curve,
without shattering?// |
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Yes. Metals, salt, ice...all crystalline and can be
carved, ground, cut or lasered into any shape you
like. |
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The reason you never see curved diamond surfaces (unlike other gemstones with chacobon cuts) is that the majority of a diamonds attractiveness is how it behaves in light, which is emphasized by facets, not smooth surfaces. |
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And Vernon, as far as your link, diamonds can withstand huge pressures, but they can also be cut by a fairly light hit, or shattered with a hammer. Diamonds are extremely anisotropic, and can be a couple orders of magnitude between their strongest and weakest plains. The diamonds used for anvils are carefully selected and positioned so that doesn't happen, but I think that would be difficult for teeth. |
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[MechE], well, the Idea does specify lab-grown gem-quality diamonds, which can have many fewer internal flaws than natural diamonds. That should make a difference, with respect to withstanding chipping or other breakage. |
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I don't think lab-grown vs. natural makes much of a
difference in that respect. As I once mentioned in
annotation to another diamond-
related post, I have shattered a lab-grown
diamond with a single blow from a 3lb drilling hammer.
Actually, 'pulverized' might be a better word. Perhaps it
was the lack of internal flaws which caused it to reduce to
such a fine powder. |
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This leads inexorably to the conclusion that the answer to the problem is not to create flawless synthetic carbon crystals, but rather carefully controlled chaotic structures which diminish the susceptibility to failure along cleavage planes. |
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High quality steels exhibit similar "controlled chaos" in their crystal structure. |
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We still assert that Platinum offers a superior material to meet the specification. Corrosion resistant, won't shatter, machinable (within limits), biologically inert. |
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It's not flaws that are the issue, it's how you hit the
diamond in relation to its crystal structure. |
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If anyone has several spare diamonds handy, I'll be happy
to smash them from a variety of different angles. Many of
you know more about this than I do, but isn't the basic
issue simply that diamonds are very brittle? |
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Has anyone suggested platinum then? |
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Or later? Given the money I've spent on dentistry, I may as well be using gold, diamonds, and platinum. |
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