For the few teeth I have repaired I have used Sculpty Clay, drywall, and plaster of paris. The repairs I did were very minor. I did use a bakeable type of clay to replace an entire cone on a mastadon tooth. It turned out so well most people can't tell where the repair is, even when I tell them it's repaired. This is the exception rather than the rule. I have also heard that some people use Bondo for larger repairs. As far as the paint is concerned, I think acrylic works best, but try to match the clay color as close as possible. I avoid paint if at all possible. Keep in mind this advice is coming from someone that has repaired less than a dozen teeth and most of the repairs were minor root chips. I have more experience with putting a root lobe back on than major repairs. Use a putty base to set the tooth in and balance the tooth so the root lobe sits on the tooth without glue. Silly Putty works great and doesn't usually stain. Put a little time into finding the best way to balance the tooth so the loose lobe sits nicely on the tooth with no problems. If you don't want glue ooze you have to use just barely enough white glue to stick the tooth and root together, not an easy task. If you use super glue you will almost always get ooze or the tooth falls apart due to lack of glue. Try this with an average quality tooth; use enough glue to make the tooth hold together and let the glue dry completely. Use a Q-tip with a paper stick (a plastic stick will melt) that has been dipped in acetone to gently "wash" the excess glue off of the outside of the tooth. Use adequate ventilation and don't try to get all the glue off in one shot, do one side at a time. If you try to remove the glue ooze all at once the acetone may penetrate the tooth and dissolve the "good" glue. This should get the glue stain off of the tooth.

There is a gel type superglue that works beautifully for the delicate repair jobs where you are trying to avoid a glue line. You can put a dot in the very center and it doesn't spread out like normal superglue. Normal superglue is what I use to harden fossils that are too big to dig in PVA (aka Vynac). It is easy to inject the stuff right into cracks. I used it on a couple of chunks of mastodon teeth with great success.

I used to dabble in tooth restoration but I quickly learned that I was better at building websites. When I did my experiments in tooth restoration, I started off using quick drying cement for repairing a root. It sticks really well, its easy to mold if you mix it right, it has a perfect consistency to maintain a "pattern" in the finished product to look more realistic (used a toothbrush for this), and when you tap on it with a knife when dry, it sounds like the actual root of the tooth. One downside is you have to paint it. I only ever used it successfully with black, because you can mix in the die/paint when you mix the concrete.  Another downside is if you do it wrong, its really difficult to do again because its concrete!

A better technique I found was to use ground up whale bone and superglue to repair roots. I would pump in some superglue, then add some bone powder / chunks of bone, allow to dry, repeat until I built up the missing area. This turned out much better because I always got bone and dirt from the location where I found the tooth to use in the restoration. The color turned out perfectly, and all I had to worry about was not gluing myself to the tooth as I shaped it. When the tooth is dry, and the resto area is shaped correctly I rubbed the dirt from the spot where the tooth was found into the restoration area to even more closely approximate the color. If the resto looked uneven, I could soak it in acetone to loosen up the superglue for a quick adjustment. Best part - no painting! This method worked really well and if I had to do it again, this is how I would do it. It just takes a while to do it right.

My only experiences with enamel repair were abominations to nature. Now, if I find something that is so good that it needs a restoration job, I have it done professionally. I tried epoxy putty, bondo, wood filler, and managed to defile evey specimen I touched. I'll spare you the stories unless you want to hear of my fantastic failures in this arena.

Be careful about purchasing shark teeth that come from Morocco.  The teeth are easily broken while trying to be removed from the concretion like matrix.  Since many locals there depend on this for income, they go to great lengths to repair specimens of all kinds, especially the shark teeth.  I believe one of the main ways to fix a root or root lobe is to use some sort of flour paste.  Someone once told me that one way to cehck and see if the tooth is all natural is to soak in it water for a minute, if its been repaired with the flour stuff, it will fall apart (deice first if you want to take the chance and possibly ruin the specimen).  I actually have a few large otodus from Morocco that I can readily see had one root lobe glued back on, and the craks filled with the flour paste or something.  I only paid a few bucks for these and whoever did the repair did a decent job.  Where you have to be careful is when you're paying top dollar for a specimen.  Also keep a careful eye out for forgeries from Morocco.  Sometime a specimen can be completely fake, as in the case of a gigantic trilobite, or maybe partially "fake" as in the case of "associated Otodus teeth still in matrix", that were actually glued to the matrix in some random fashion.  I saw someone a few months ago selling some slabs of matrix with several Otodus teeth on them, and it was being sold as all natural.  It was a scam!  Was it just coincidence that every tooth shown on the slab of matrix was "display side up", and the entire tooth was exposed, not protruding from within the matrix etc. 

Daryl.

One of the things I find most amazing as I read through these various threads is the commonality of ideas employed in this hobby.  For example, I used to fill the cracks in the roots of shark teeth with stuff like wood putty, crayon, etc.  Then one day I got the unique idea to take home some of the same clay/dirt chunks that the teeth were coming out of so I could match the color - it worked great.  Turns out other folks have been not only doing that, but also coming up with craftier ideas like DW's grounding up whale bones.

As for BRM's tapping of the teeth, I've been doing that too for a few years, but I do it when trying to determine if the specimen is a fossil or modern.  We get a lot of various vermon that fall off the 80ft cliffs and their remains show up from time to time, looking like fossils, until you tap them against something metal and you here more of a thunk thunk than a tink tink.

Here's one more example of two people coming up with the same idea completely independent of each other.  My friend started polishing some of his shark teeth a few years ago with his Dremel.  Not too much shine, just enough to clean the surface up and bring out that luster.  Too much shine and the tooth looks fake or unnatural.  Anyhow, I asked him what kind of polishing compound he used.  Turns out he went into his garage and found some stuff sitting on the shelf that he used on his car's wheels - Mother's Aluminum Wheel Polishing Compund.  Turns out the stuff works great because it comes off easy, isn't too gritty to scratch the enamel, and he didn't have to go shopping for something else.  Well, at one of our recent club meetings, another friend of ours was there and looking at some of my other friends teeth and commented on how awesome they looked.  When my friend said that he polished them a little with his Dremel, the other guy asked, "oh ya, so do I, and I use Mother's Aluminum Wheel Polishing Compound"!  I was shocked.  How the heck did these two guys come up with the same polishing compound - coincidence maybe, it was wierd.

It's also fun to read how folks clean the teeth after they get them home.  My one friend lets his soak in fresh water for a few days, then air dries them out on a towel.  Someone else I know bakes them in the oven, and someone else I know nuke's em in the microwave, and yet another person I know sets them out on his back porch in the Sun to try to bleach them.

Daryl.

The burn test works, I've used it before, but I do things a little differently. I use a vice grip to hold a needle, which I get at least red hot, and touch the needle to the presumed fossil and do the sniff test. It also works to separate amber from plastic imitations. There are lots of tricks out there and the best have been re-invented many times over. Red rouge also works well to get light mineral deposits off of teeth. You can also use a green plastic scratch pad with baking soda to clean the teeth. Use a stiff bristle tooth brush and baking soda to clean between the cusp and blade of a tooth. A super fine needle will remove gunk from between serrations. A razor blade at a low angle with gentle pressure will remove gypsum from enamel  as long as the tooth isn't too crusted. Vinegar will remove calcium deposits from teeth, but the tooth must be thoroughly cleaned of the vinegar afterwards to avoid the formation of internal acetate crystals that can cause the tooth to swell and come apart. A bleach solution will remove modern barnacles and small oysters. And the list goes on..........