technique #1)
Get some #10 superglue from StewMac, the real thin stuff. Use a toothpick to perform the "dropfill" technique. Dip the toothpick in the superglue untill you have a single drop hanging from the tip. Touch the drop (but not the toothpick) to the dent. It will spread out flat. Reapeat as necessary to fill the dent transparently with a shine on top.
technique #2)
Steam out the dent with a wet washcloth and a hot soldering iron. Heat the iron untill it is hot. Wrap the tip in the wet washcloth and apply to the dent. The hot iron will push steam into the collapsed, crushed wood fibers and the steam will re-inflate the fibers. Use for just a few moments to avoid heat damage to the finish.
Either way should work. Good luck!