Mechanical Instruments Flashcards
1
Q
What are mechanical scalers used for?
A
To remove plaque, calculus and extrinsic stain
2
Q
What are the 2 classifications of mechanical scalers?
A
Ultrasonic
Sonic air
3
Q
At what frequency do ultrasonic scalers operate?
A
20,000 - 50,000 Hz
4
Q
What are the 2 types of ultrasonic scalers?
A
Magnetostrictive
Piezoelectric
5
Q
Magnetostrictive scalers
A
- 20,000 - 45,000 Hz
- have interchangeable prophylaxis inserts - metal strips in a ferromagnetic rod
- e.g. cavitron, cavi med
6
Q
How do magnetostrictive scalers work?
A
- high freq electrical energy converted to mechanical energy
- when electric current applied, magnetic field created
- expansion and contraction of rod causes tip vibration
7
Q
Why do ultrasonic scalers need water supply?
A
Ultrasonic waves given off as heat. Water keeps hand piece cool and prevents trauma to pt. Water also helps clear debris from working site.
8
Q
Piezoelectric scalers
A
- 20,000 - 50,000 Hz
- quartz crystals
- e.g. Piezon, prodentec
9
Q
How do Piezoelectric scalers work?
A
- quartz crystals in handpiece change shape when electricity supplied causing linear vibrations in tip
