You might want to try mixing a black and white picture of a tooth with an iceberg terrain in the terrain editor.  You can make a simple picture using a paint program.  Make the tooth shape white and the background black. 

Create a terrain and double click it to get the terrain editor.  Click 'reset'  then 'iceberg'.
Click 'picture' and load your picture.  Use the little button at the top right of the pic to invert the colors.   Use the mixing slider to try to get something that might work.  

Not sure if this is what will work for you or not, but give it a  try.  :)