Module 2 Flashcards
(89 cards)
What is the main action of ultrasonic and sonic scalers?
mechanical
what other factors of ultrasonics and sonics play a role in debridement
irrigation and cavitation
What is the mechanical action of ultra and sonics?
-coverts electrical energy or air pressure into high frequency sound waves
What do the sound waves produce?
rapid vibrations
What happens to the calculus when sonic or ultrasonics are used?
calculus shatters
What is required to dissipate heat produced at the vibrating tip
water
what is cavitation
action created by formation and collapse of bubbles in the water by high frequency sound waves surrounding an US tip
what is the effect of cavitation?
cable of destroying bactera and can remove endotoxins from the root surface
What is irrigation
the water spray penetrates base of the pocket and flushes out debris microorganisms and endotoxinx
what is believed to have a disruptive effect on surface bacteria
acoustic turbulence
what is the amplitude?
distance of tip measured in micrometers
what determines the power output of the instrument
the distance of tip/amplitude
what is frequency
speed of movement, cycles per second
What are the 2 types of US scaling devices?
- magnetostrictive US
- piezoelectric US
What is the composition of magnetostrictive US scalers?
- conventional magnetostrictive units- long stack of metal strips
- ferromagnetic units- fragile ferric rod, generates less heat
What is the activation of the magnetostrictive US?
- vibrations occur when electric current is applied
- there is expansion and contraction of metal strips
what is the tip motion of a magnetostrictive US?
- conventional moves in an elliptical pattern
- ferromagnetic rotates 360*
What is the tip shape of a magnetostricive US?
round
What is the compositoin of a Piezoelectric US?
ceramic rod
What is the activation of a piezoelectric US?
dimensional changes in quartz or metal alloy crystal transducers housed in the handpiece
what is the tip motion in piezoelectric US?
linear pattern, only forward and backward
what surfaces are active on the tip of a piezoelectric US?
lateral surfaces
What is the technique for a piezoelectric US?
- lateral surface of tip in contact w tooth
- only the terminal 2-3 mm of tip
- keep lateral surface adapted
what is the tip shape of a piezoelectris US?
varies from trapezoidal with angular edges to round to bladed