instrumentation
Frequency is related to
A. Stroke length of the instrument
B. Vibration of the instrument
C. Speed of the instrument
D. B and C
E. All of the above - ✔✔ correct answer D
Amplitude is related to
A. Stroke length of the instrument
B. Vibration of the instrument
C. Speed of the instrument
D. A and C
E. All of the above - ✔✔ correct answer A
Measures of how many times a powered working end vibrates per second
A. Amplitude
B. Frequency
C. Both
D. Neither - ✔✔ correct answer B
Measures how far the powered working end moves back and forth during one cycle. Adjusted using
the power setting on an ultrasonic devices
A. Amplitude
B. Frequency
C. Both
D. Neither - ✔✔ correct answer A
,Hygiene Exam 1 GEHRIG powered
instrumentation
Research investigation has found significant difference in the cleaning efficacy of ultrasonic
instruments when operated at high power levels or medium power levels. The higher the power
setting, the longer and more forceful the stroke is.
A. Both true
B. Both false
C. First true, second false
D. First false, second true - ✔✔ correct answer D
To maximize patient comfort and minimize potential damage to the tooth surface, the power setting
of ultrasonic devices should rarely be placed above _______ setting. Most slim-diameter working
ends cannot be used at ______ power levels because of risk of breakage.
A. Low; medium
B. Medium; medium
C. Medium; high
D. High; high - ✔✔ correct answer C
Dentsply Cavitron makes two slim-diameter working ends, called ________ inserts that are specially
designed to withstand use on high power without danger of breaking. Parkwell makes the ________
inset that can be used on high for removal of tenacious calculus
A. Burnett, Thin-Sert
B. Thin-Sert; Burnett
C. Thin-Sert; Piezo
D. Slim Series; Burnett - ✔✔ correct answer B
Frequency + amplitude =
A. Cavitation
B. Fluid lavage
,Hygiene Exam 1 GEHRIG powered
instrumentation
C. Cleaning efficiency
D. A and B only - ✔✔ correct answer C
Low frequency + low amplitude =
A. Few vibrations and short strokes
B. Ideal for disruption of plaque biofilm from root surface deplaquing
C. Many vibrations and long strokes
D. Ideal for removal of tenacious calculus deposits - ✔✔ correct answer A, B
High frequency + high amplitude =
A. Few vibrations and short strokes
B. Ideal for disruption of plaque biofilm from root surface deplaquing
C. Many vibrations and long strokes
D. Ideal for removal of tenacious calculus deposits - ✔✔ correct answer C, D
The movement of magneto working end PRIMARILY moves in an _________ motion. However, the
motion ranges from nearly linear, elliptical or circular depending on type of unit, shape and length of
working end.
A. Linear
B. Ellipitcal
C. Circular
D. Angled - ✔✔ correct answer B
Working end is activated by dimensional changes in crystals housed within the handpiece as
electricity is passed over the surface of the crystals.
A. Piezo
B. Magneto
, Hygiene Exam 1 GEHRIG powered
instrumentation
C. Sonic
D. Air-polisher - ✔✔ correct answer A
The resultant vibration of the piezo working end produces movement that is PRIMARILY __________
in direction.
A. Linear
B. Ellipitcal
C. Circular
D. Angled - ✔✔ correct answer A
For _______ devices, only the working end needs to be cooled with water to prevent overheating.
With _______ devices, the handpiece AND working end should be irrigated with water as coolant to
prevent overheating.
A. Magneto, piezo
B. Piezo, magneto
C. BOTH need water through handpiece AND working end
D. BOTH only need water at working end - ✔✔ correct answer B
Waterflow produced by ultrasonic instruments
A. Can result in heat damage and dental pulp if not enough
B. More water needed for calculus removal
C. Less water flow needed for deplaning
D. A and B only
E. All of above - ✔✔ correct answer E
When using ultrasonic instruments, one of the most common mistakes made by beginning clinicians
is using too ______ water. A ______ handpiece indicates inadequate water flowing through
handpieces and working end.