Possible Clues:

• "Remember your training, people!," and what can be said about the starts of 17-, 24-, 51-, and 63-Across
• "It's the real deal!"
• After failing to bore a hole through the tooth with a Waterpik, the clumsy dentist exclaimed ..
• "It's for real!"
• Danish trio still playing? It's really happening! (4,2,3,1,5)
• Scary announcement