511. When the dentist enters the operatory, the patient, who is new to the office, stands close to the wall, has his arms folded, and is looking at the floor. The dentist should initiate communication by saying which of the following?

A. Let's get going, I've got a lot to do.
B. What are you angry about?
C. Didn't my assistant get you seated?
D. You seem uncomfortable; did you have a bad dental experience?
E. Hi, I'm Doctor Wilson, what brings you here today?

510.If a patient suddenly becomes unconscious during treatment, the practitioner should immediately assess the patient's

A. airway and pulse.
B. airway and blood pressure.
C. pulse and blood pressure.
D. color and pupils.

509. A 2-day-old developing plaque consists primarily of

A. Treponema species.
B. Bacteroides species.
C. filamentous organisms.
D. gram-positive cocci and rods.
E. a structureless, non-mineralized pellicle.