General: This is a good attempt at a documentary shot. If this is what you were trying to accomplish then you succeeded.
Composition: The fingers are a bit distracting. Showing more teeth and concentrating on either the lower or upper set to emphasize a particular area could possibly improve the composition.
Exposure: In general the exposure is good. There is just one hot spot on a tooth on the upper right. This could probably be corrected by noting where the light is coming from and adjusting the angle accordingly.
Impact: Looking at someones teeth is usually not very appealing (except for a dentist). What might help is isolating one tooth. That said, for the purpose you propose in your comments you could probably succeed with this type of photo.
Sorry about inflicting this image on everyone..... was a bit of a last minute effort, i just found it funny because it was actually a dentists teeth, all be it just after bithday cake!!
Every comment about how much they would hate it if this was a real dentist made me laugh even more!!!!
anyway.... sorry again.... but i guess no one will read this anyway...
Whoever this is might want to floss more. This is a pretty graphic image of some of the worst teeth I've ever seen, but it doesn't seem to fit the "at work" assignment. This should be on a billboard to show people what happens if they don't take basic care of their teeth.
Not a bad idea, and certainly unusual.. But I am not sure how much of "people at work" it shows.. I would never have gone to a dentist with fingernails that dirty ;) (4)