Check this link out:
<a href="http://cudental.creighton.edu/HTM%5Chistory2001.PDF" target="_blank">http://cudental.creighton.edu/HTM%5Chistory2001.PDF</a>
It also says this:
This design uses as its central figure a serpent entwined about an ancient Arabian cautery in
the manner of the single of Aesculapius, the Greek god of medicine, coiled about a rod. The
Greek Letter D (delta), for dentistry, and the Greek letter O (omicron), for odont (tooth)
form the periphery of the design. The word ?Dentistry? appears on the lowest part of the
letter O. In the background are 32 leaves and 20 berries, representative of two dentitions.
Because colors are sometimes asked for, the following are suggested: the background in a
shade of lilac, the official academic color of dentistry (Descriptive Color Names Dictionary
of the Containers Cooperation of America, 1950, color chip 12 ge); the letter O in gold; the
letter A in black; the cautery in gold outlined in black; and the leaves and berries merely
outlined in black on the lilac background.