Subject: Module 26: Powered Instrument Design and Function
1. What mechanism does a powered instrument use to fracture calculus deposits from the tooth
surface?
A. Rapid energy vibrations of the instrument tip
B. Tiny bubbles that collapse, producing shock waves
C. Force of water spray exiting the tip
D. Electricity
Answer: A
Subject: Module 26: Powered Instrument Design and Function
2. Modern slim-diameter powered instrument tips are as effective as hand instruments in
removing all of the following except _____.
A. supragingival calculus deposits
B. subgingival calculus deposits
C. cementum
D. plaque biofilm
Answer: C
Subject: Module 26: Powered Instrument Design and Function
3. The water that exits near the tip of an ultrasonic instrument tip _____.
A. cools the instrument tip
Copyright © 2016 by Jones & Bartlett Learning, LLC, an Ascend Learning Company 26-1
,B. removes calculus deposits
C. warms the instrument handpiece
D. cools the instrument tip and washes bacteria from the pocket
Answer: D
Subject: Module 26: Powered Instrument Design and Function
4. The fluid stream flowing through a powered instrument tip produces bactericidal effects. Slim-
diameter instrument tips penetrate deeper into periodontal pockets than do hand instruments.
A. Both statements are true.
B. Both statements are false.
C. The first statement is true; the second statement is false.
D. The first statement is false; the second statement is true.
Answer: A
Subject: Module 26: Powered Instrument Design and Function
5. Slim-diameter powered instruments are more effective in treating class II and III furcations
when used by experienced clinicians. Hand instruments have been shown to be more effective in
deplaquing root surfaces.
A. Both statements are true.
B. Both statements are false.
C. The first statement is true; the second statement is false.
D. The first statement is false; the second statement is true.
Answer: C
Copyright © 2016 by Jones & Bartlett Learning, LLC, an Ascend Learning Company 26-2
, Subject: Module 26: Powered Instrument Design and Function
6. The water flowing through a powered instrument tip forms tiny bubbles that collapse,
producing shock waves that destroy bacteria by tearing the bacterial cell walls. This mechanism
of action is termed _____.
A. acoustic turbulence
B. cavitation
C. deplaquing
D. aerosol production
Answer: B
Subject: Module 26: Powered Instrument Design and Function
7. When working with a powered instrument, the swirling effect produced by the water stream
within the confined space of a periodontal pocket is termed _____.
A. acoustic microstreaming
B. cavitation
C. deplaquing
D. aerosol production
Answer: A
Subject: Module 26: Powered Instrument Design and Function
8. The intense swirling effect of the fluid flow over a powered instrument tip will fracture
calculus deposits from the tooth surface. Powered instruments are capable of dislodging plaque
biofilm slightly beyond the reach of the instrument tip.
A. Both statements are true.
B. Both statements are false.
Copyright © 2016 by Jones & Bartlett Learning, LLC, an Ascend Learning Company 26-3
1. What mechanism does a powered instrument use to fracture calculus deposits from the tooth
surface?
A. Rapid energy vibrations of the instrument tip
B. Tiny bubbles that collapse, producing shock waves
C. Force of water spray exiting the tip
D. Electricity
Answer: A
Subject: Module 26: Powered Instrument Design and Function
2. Modern slim-diameter powered instrument tips are as effective as hand instruments in
removing all of the following except _____.
A. supragingival calculus deposits
B. subgingival calculus deposits
C. cementum
D. plaque biofilm
Answer: C
Subject: Module 26: Powered Instrument Design and Function
3. The water that exits near the tip of an ultrasonic instrument tip _____.
A. cools the instrument tip
Copyright © 2016 by Jones & Bartlett Learning, LLC, an Ascend Learning Company 26-1
,B. removes calculus deposits
C. warms the instrument handpiece
D. cools the instrument tip and washes bacteria from the pocket
Answer: D
Subject: Module 26: Powered Instrument Design and Function
4. The fluid stream flowing through a powered instrument tip produces bactericidal effects. Slim-
diameter instrument tips penetrate deeper into periodontal pockets than do hand instruments.
A. Both statements are true.
B. Both statements are false.
C. The first statement is true; the second statement is false.
D. The first statement is false; the second statement is true.
Answer: A
Subject: Module 26: Powered Instrument Design and Function
5. Slim-diameter powered instruments are more effective in treating class II and III furcations
when used by experienced clinicians. Hand instruments have been shown to be more effective in
deplaquing root surfaces.
A. Both statements are true.
B. Both statements are false.
C. The first statement is true; the second statement is false.
D. The first statement is false; the second statement is true.
Answer: C
Copyright © 2016 by Jones & Bartlett Learning, LLC, an Ascend Learning Company 26-2
, Subject: Module 26: Powered Instrument Design and Function
6. The water flowing through a powered instrument tip forms tiny bubbles that collapse,
producing shock waves that destroy bacteria by tearing the bacterial cell walls. This mechanism
of action is termed _____.
A. acoustic turbulence
B. cavitation
C. deplaquing
D. aerosol production
Answer: B
Subject: Module 26: Powered Instrument Design and Function
7. When working with a powered instrument, the swirling effect produced by the water stream
within the confined space of a periodontal pocket is termed _____.
A. acoustic microstreaming
B. cavitation
C. deplaquing
D. aerosol production
Answer: A
Subject: Module 26: Powered Instrument Design and Function
8. The intense swirling effect of the fluid flow over a powered instrument tip will fracture
calculus deposits from the tooth surface. Powered instruments are capable of dislodging plaque
biofilm slightly beyond the reach of the instrument tip.
A. Both statements are true.
B. Both statements are false.
Copyright © 2016 by Jones & Bartlett Learning, LLC, an Ascend Learning Company 26-3
