If you are a dentist, or for that matter, even if you aren't, I guess you could still try something...
Go to the dentists in your area, and get them to "review" the book.
First, it might tell you whether the work needs a little polishing (pardon the pun!), then after a review, you might ask them where and how they would be most likely to respond to an offer for the book.
Maybe they are members of an association that publishes a newsletter, and you might start with a small display ad in the publications the dentists read.
"Pulling For You",