I needed to fix a broken nail and picked up an "Acrylic Fill Kit". I thought it would be some kind of fingernail epoxy. Much to my amazement, I discover that this is actually the same stuff that dentists (and those people who make custom vampire fangs for people) use to make temporary caps/teeth. I have used dental acrylic but decided that the risk of the chemicals (they're nasty) wasn't worth the nice, realistic teeth you get, especially when taxidermy jaw sets are both inexpensive and realistic (and finished!).
But...if you ever break a rigid tooth or claw, this kit is exactly what you need for a quick fix! You would need a paper cup (not plastic!) and put the powder in and add the "acrylic liquid" drop by drop until the mix is no longer powdery (it'll look like wet sugar). Then you have about twenty-five seconds to pour it into a flexible mold or use a popsicle stick (or equavalent-- piece of cardboard or something) to scoop it into a flexible mold. In smaller quantities (like the ones mentioned in the instructions), you can also use this as an adhesive or, if you're desperate, you have a few seconds to mold it into a tooth or claw shape.
To use this like a putty, mix as above and use a stick to stir it...wait until it starts to get thick, then scoop it out (wear gloves!) and start to shape it. You only have about twenty more seconds to work it until it hardens, so be efficient. After it hardens, you can sand and polish it; takes paint well too. Neat stuff, but definitely respirator/outdoor material: the monomer is so nasty that you will absorb it through your skin and even your eyes. Brain and liver killer.
Still, it's a good resource for those odd emergencies!
Here's a good place to get it online (I love Walgreens!):http://www.walgreens.com/store/product.jsp?id=prod1509161&CATID=100620&skuid=sku1509150&V=G&ec=frgl_693102#