Answer:

DDS

Answer	Crossword Clue
DDS	Orthodontist's deg
DDS	Tooth pro's deg.
DDS	Toothy degree

DDS	Doc Holliday's deg.
DDS	Driller's deg.
DDS	Oral surgeon's deg.
DDS	Driller's abbr.
DDS	Calculus deg.?
DDS	Periodontist's deg.
DDS	Deg. held by Doc Holliday
DDS	Tooth puller's deg.

DDS	Tooth-care expert's deg.
DDS	Tooth-care deg.
DDS	Cavity filler: Abbr.
DDS	Filling station worker?: Abbr.
DDS	Cavity filler's title: Abbr.
DDS	Driller's letters
DDS	One asking you to rinse: Abbr.
DDS	Cavity filler's deg.

DDS	Bridge installer's deg.
DDS	Deg. for Tim Whatley on "Seinfeld"
DDS	Smile specialist's deg.
DDS	ADA member
DDS	Cavity-filler's deg.
DDS	One involved in canine care (abbr.)
DDS	Degs. for drillers and fillers
DDS	Filling station letters?

DDS	License to drill, for short?
DDS	Driller's title (abbr.)
DDS	Tooth examiner's letters
DDS	Oral care deg.
DDS	Deg. for a crowning achiever?
DDS	Drilling letters
DDS	Canine expert's deg.
DDS	Crown installer (abbr.)

DDS	Dentist's deg.
DDS	Deg. of the professional who may instruct you to do the last words of the four longest puzzle answers
DDS	Enamel worker's degree (abbr.)
DDS	Deg. for a bridge builder?
DDS	Bridge maker's deg.