I described how I made the teeth and showed them already attached to the skull but I didn’t describe the details of the process yet. So here it is.
To start you need a candle, a lighter or matches, gloves, cutting pliers. You also need transparent plastic hanger like this one:
It should have a tubular structure and the tubes should be about 0.8cm in diameter. Try to get one that has no bubbles in the plastic or that has at least some long sections (more than 3cm) without any bubbles. Break it apart.
Choose a piece of the hanger which has no bubbles, turn it slowly over the candle and move it sideways (heat about 2 cm of plastic). Do that for a few seconds (10-15 seconds). Don’t let the flame touch the plastic. You should do this in a ventilated area (and use leather gloves to protect from the hot plastic).
You will notice that after a few seconds the heated part will become brighter and translucid (with very small bubbles). You can move it away from the candle now, and it will continue to heat and become softer.
When that happens, pull slowly, then stronger, until it starts to give in.
Hold it over a curved surface to shape it if you wish (a tube with a diameter of 10cm if you are making curved pterosaur teeth). Wait for some 15 seconds and when it becomes solid you can let it go.
Practice leaving the plastic under the flame for more or less time until you achieve the desired results. If it heats too much, when you pull it may get too thin or break. Try pulling slower. You can obtain different effects with the plastic pulling faster or slower, letting it go before solidifying, or heating more or less and even letting it break. Be careful to not burn the plastic. It gets black, unusable and the smoke is very toxic.
When solid, you can break the halfes apart, trim to the desired size, and you have two teeth.
But the melted plastic doesn’t really look like teeth, does it? You have to carve it a bit using a knife as if you were sharpening a pencil until you have something in the shape of sharp teeth.
The next step is to cut the teeth out. Not so easy. This kind of plastic is very hard and you won’t be able to cut it with regular pliers. You can use a hot knife or cutting pliers of the kind that cuts padlocks. I tried smaller ones but they would crack the plastic. Protect yourself cutting the plastic in a bag or box, since the parts may go flying out when split apart.
That’s it. Now we have teeth.
The last step is to attach the teeth with epoxi resin to the skull using a picture of the fossil as a guide.