Could you make the smaller res images just show the black area, or not shrink it as aggressively? Or else just keep the tooth part and forget the slide frame.
Does the application have anything to do with X-rays?
The last time I went to a dentist, they wanted my whole family to get root planing at a cost of over $2,000. When I asked for a less expensive alternative, they never called me back. I realize the professional associations are after them to extract as much money from each patient as possible; the same attitude is destroying the veterinary profession.
So, if you are making a package to sell to a dentist, make sure you extract as much money from them as possible. Show no mercy.