Tooth cells + rejection

B

BigBlueHead

Great Tealnoggin!
Registered Senior Member
I have been told that our teeth are surrounded by a layer of fibrous cells that root them to our bones. This led me to wonder about a couple of things:

1) Are our teeth inorganic? (I mean, the hard mineral part, not the interior nerves/vessels)

2) Do these cells therefore permit the human body (esp. bones and surrounding tissues) to bond with any relatively inert mineral?

3) If this is so, could these root lining cells be used to contain cybernetic implants within the human body without the usual problems of the implants?

I ask this at least partly because tooth implants (where a metal sleeve is implanted into the jawbone) apparently cause a disintegration of the jawbone in the long term. This may represent a solution, but I'm not exactly a tooth/implant expert.
 
Researching enamel isnt easy.

More than 98 percent of tooth enamel consists of carbonated calcium hydroxy-apatite.
Basically, teeth are made of rock.

Tooth enamel begins to form in the human embryo when a specialized layer of cells, called ameloblasts, in the embryonic tooth bud secretes amelogenin proteins. The amelogenins self-assemble to form the extracellular matrix within which the inorganic crystals of mineral start to form.

Chemically, the mineral crystals in tooth enamel are a calcium hydroxy-apatite formed from calcium and phosphate ions, which are transported into the nanosphere matrix by ameloblast cells.
 
ask spuriousmonkey he dealt with teeth and teeth growth.

but first:

1. Teeth and bone are made from the same substance (calcium carbonate, though teeth are at a much higher density and purity.

2. one should not think of a biologically grown crystal such teeth and bone as inorganic, bone and teeth are accepted by the body as components of it.

3. No cybernetic implant would need to only be connected to neurons, standard silicon implants lased with special nutrients, promoters or even stem cell grown neurons can have neuron dendrites and axons grow on them. Implants in bone would only need a titanium pin or hook as bone for some reason fuses with titanium like glue, were as iron or other metals are rejected by bone and tissues.
 
WCF, I'm not talking about neural connectivity, I'm actually thinking about a much lower-tech problem.

I understand that even titanium implants seem to promote some kind of bone reduction in the long term, as with the tooth implants now offered by dentists. Whatever bone they are implanted in will die away from the implant site and eventually come loose.

I am talking about the cells that specifically provide a substrate for your body to adhere to on the mineral surface of the tooth. My wishful theory is that these cells could similarly permit our bone tissue to bond to other surfaces, like those of an artificial joint. (Since artificial joints currently suffer the same kind of localized bone degeneration that tooth implants do.) This might extend the lifetime of artificial joints, although I don't know if the root cells are capable of standing up to the shearing forces of being, say, a knee joint.

I was sorta hoping that the spurious simian would weigh in on this topic since I remember reading some of his other tooth-related posts...

But you guys are still great! ;)
 
From what I have been told (by dentist) titanium implants promote bone fusion. Perhaps there were not updated on resent research.

Perhaps it would be best to ask this question on a dentistry forum.
 
I had hoped to go to biologists and not dentists, because I have heard conflicting claims in this field. I do know that most bone implants - hips, knees &c, suffer mechanical failure in their bone interfaces after 10-15 years.
 
Titanium like any other metal suffers from metal fatigue: it would not be unreasonable to think after 10-15 years the implant its self fails rather then the bone.
 
Originally posted by WellCookedFetus
ask spuriousmonkey he dealt with teeth and teeth growth.

but first:

1. Teeth and bone are made from the same substance (calcium carbonate, though teeth are at a much higher density and purity.

2. one should not think of a biologically grown crystal such teeth and bone as inorganic, bone and teeth are accepted by the body as components of it.
Click to expand...

That's all quite true what Fetus says here. And as for the second poster, our teeth are of course only partially covered with enamel. Only the crown is covered by this matrix, with underneath it the mesenchymal derived dentin. Dentin is almost exactly identical to bone. The root surface is not covered by enamel at all. Here only the dentin is present. The epithelium of the root does not differentiate into ameloblasts at all. Instead it fragments and forms the so-called epithelial cell rests of Malassez. The exact function of this epithelium is not known, although there are some ideas. It needs to fragment because cementoblasts invade this layer and together with the other tissue surrounding the tooth forms the periodontal ligament. A complex structure with different cells and matrices that connects the root to the jawbone.

As you might have guessed from this is that the formation of this very important structure, the periodontal ligament, is a complex process and dependent on many factors.

It will not occur on for instance a enamel surface. It will most likely not occur on any other surface. The process will probably also be limited to a certain time during development, or dependent on certain factors or environment.

Hence there are many problems and many of the basics of this process are still not understood.
 
Uh yeah, Cthulu Fthagn and all that...

Maybe the reason you don't know anything about teeth is because the Old ones don't have any anymore, or something.
 
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