I know do have a bit of experience with furniture and instrument repair, and I agree with Eggy and the others here, that a shallow dent is often a candidate for the steaming technique, followed by finish touch-up work. You do need to gently remove the top finish or poke pin holes in the finish to let the steam into the wood. Basically it involves using a damp clean rag and a hot iron tip on the spot and the resulting steam swells the cells of the wood back up. It can take a few times to swell the dent back up, and you need to know what you're doing in regards to the minor finish touch-up work afterwards, in order to get it to blend in. I have had very good success with this method. Dan Erlewine also talks about this technique in his guitar repair guides. Furniture repair persons, and master refinishers have been doing it for years. Your other choice is having someone do a drop fill job, usually with a clear super glue for a poly finish repair, followed with a whole bunch of carefully applied wet sanding and polishing work. I've done that too. On most really dinky dings, even on the back of a neck, I just leave them alone when it comes to my stuff.