Possible Clues:

• Cavity filler's letters, or, said another way, a hint to 17-, 29-, 49- and 65-Across
• Canine doc's deg.?
• Oral specialist
• Canal checker?: Abbr
• Tooth filler, for short
• Smile specialist's deg
• Deg. for Tim Whatley on "Seinfeld"
• Deg. for Painless Parker
• License to drill? (Abbr.)
• One concerned with 47-Across, for short