As always: Astute observations
I considered this and dismissed the idea outright. Pearly whites may kill the illusion, but gunky teeth would have killed the picture, demolishing almost any chance of the shot becoming an advert. Please continue in the cranky editor role--you have a sharp eye and a solid knowledge of what constitutes good photography.
For what you were trying to achieve, you hit it on the head. I certainly agree that if the goal was a possible advertising image, probably better the sparkly teeth are spotless. Just consider my previous comment in the context of seeing the picture simply as an artistic illusion rather than a commercial image... cheers! -phil
BTW: I'm always fascinated with what you'll come up with next.