2. ULTRASONIC SCALERS
Ultrasonic scalers are electronically powered devices that produces
vibratory motions to fracture deposits from the tooth surface
In 1950 ultrasonics was first introduced for periodontal procedures
PARTS :
3. PIEZOELECTRIC SCALER
In 1880 pierre and Jacques curie found that crystals of various
materials placed under mechanical stresses produce electrical
charges on their surface
The conversion of mechanical into electrical energy is called
piezoelectric effect
ultrasonic
Piezoelectric scaler Magnetostrictive scaler
5. the tip movement is generally linear and allows two sides of the tip to
be active
Piezoelectric tips are small and can
be separated from handpiece
MAGNETOSTRICTIVE SCALER
These scalers are made up of metal stacks or rods
which is inserted into the handpiece
when an electric current passes through the metal
stack an electromagnetic field is produced that
changes the dimensions of the metal stack
produces ultrasound vibrations dissipates heat
6. All the sides of the tip are used leads to cavitation effect
which is more effective in the removal of pathogens
7. MECHANISM OF ACTION
High frequency sound waves are the principal actions of
ultrasonic scaling instruments. These waves vibrate at a rate of
24,000-50,000 cycles per second . conversion of high frequency
electric current into mechanical vibrations are attained by either
magnetostrictive or piezoelectric scalers
consists of
Frequency
Amplitude
Stroke
Water flow
8. FREQUENCY –refers to the no of cycles completes by the scaler
tip in linear , orbital , elliptical strokes per unit time . Higher
frequency refers to the lesser active area of the tip
STROKE – refers to the maximum distance the insert tip travels
during one cycle or one stroke path
AMPLITUDE – equal to the one half the distance of stroke
power knob/setting on the unit controls the length of the insert
during one cycle
Higher power setting – longer stroke pattern
Lower power setting - lesser stroke pattern
9. WATER FLOW – controlled by the water knob and contributes
to three physiological effects
Acoustic streaming
Acoustic turbulence
Cavitation
ACOUSTIC STREAMING
Unidirectional fluid flow caused by ultrasonic waves produced by rapid
movement of ultrasonic scalers
ACOUSTIC TURBULENCE
created when the movement of the tip causes the water or
coolant to accelerate producing an intensified swirling effect
10. Cavitation - leads to shock
waves which when contacts the
tooth surface releases energy
which disrupts the bacterial cell
wall and spirochete cell
membrane
CONTRAINDICATIONS
1. patients with cardic pacemakers
2. patients with known communicable disease
3. chronic pulmonary disorder
4. porcelain bounded restoration
5. patients with titanium implants
