Includes basics of ultrasonics. Definition, History, Principles of endosonics, Classification, Uses and

1. ULTRASONICS:
BASICS AND
PRINCIPLES
-MRINALINI

2. Sound
waves
•Organized mechanical vibrations travelling through a medium
•Travel through a given medium at a specific speed or velocity
•When encounter a boundary with a different medium they will be
reflected or transmitted
•Oscillate at a specific frequency, or number of vibrations or cycles
per second
•Human hearing: maximum frequency of about 20,000 cycles per
second (20 KHz), ultrasonic flaw detection applications : between
500,000 and 10,000,000 cycles per second (500 KHz to 10 MHz)
•Ultrasonics: Short wavelength, much more sensitive to small
reflectors
https://www.radiologycafe.com/medical-students/radiology-basics/ultrasound-overview

3. 20Hz 20KHz 20MHz 200MHz
INFRASOUND ACOUSTIC
(HUMAN
HEARING)
ULTRASOUND
MEDICAL THERAPY
MEDICAL DIAGNOSTICS

4. 1794: Italian physiologist Lazzaro
Spallanzani: Echolocation in bats. Emits a
high frequency sound to gauge the distance of
the object based on how long it takes for
waves to come back
1877: Brothers Pierre and Jacques Curie
discovered piezoelectricity ie ability of
solid material to generate electricity in
response to applied mechanical stresses
1912: After the sinking of titanic, Paul
Langevin used the principle of
piezoelectricity to find iceberg
1942: Karl Dussik used ultrasonic beams
to detect brain tumors.
1949: George Ludwig used it for
diagnosing gall stones 1958: Ian Donald introduced ultrasound
machine

5. HISTORY(DENTAL)
1955: Zinner, remove deposits from tooth surface
Introduced in endodontics by Richman in 1957
Martin et al. : Ability of ultrasonically activated K-
type files to cut dentin
Developed and promoted by Howard Martin and
Walter Cunningham in 1976
Newman PG, Rozycki GS. The history of ultrasound. Surgical clinics of north America. 1998 Apr 1;78(2):179-95.
Ghorayeb SR, Bertoncini CA, Hinders MK. Ultrasonography in dentistry. IEEE transactions on ultrasonics, ferroelectrics, and frequency control. 2008 Jun

6. CLASSIFICATION
Based on frequency of vibration and source of power:
Ultrasonics: Generated vibrations above audible range
powered by electric current that passes through a
lamellar arrangement of metal plates
Sonics: Produces vibrations below the audible
frequency range by means of compressed air
Difference: Power source, Frequency of vibration,
type of handpiece

7. ULTRASONIC WAVES ARE PRODUCED
BY
MAGNETOSTRICTIVE PIEZOELECTRIC
ENDODONTICS

8. MAGNETOSTRICTIVE
Converts electromagnetic energy into
mechanical energy
20-25KHz
Heat generation
Requires cooling system
Requires compressed air
and
special tube
connections
to handpiece
PIEZOELECTRIC
A crystal is used that changes dimension
when electrical charge is applied,
deformation of this crystal is converted
into mechanical oscillation
30-35KHz
No heat generation
Does not require
cooling system
Built in pump
Busslinger A, Lampe K, Beuchat M, Lehmann B. A comparative in vitro study of a magnetostrictive and a piezoelectric ultrasonic scaling instrument. Journal of clinical
periodontology. 2001 Jul;28(7):642-9.

9. Very little heat
is generated
Creates a linear
back-and-forth
tip motion
Improved
ergonomics
If water is used, a
low volume aerosol
mist is all that is
required,
improving vision
and patient comfort
PIEZOELECTRIC(PIEZO: PUSH or PRESS)
Electrical current
generates a wave in
the crystals (ie, series
of ceramic discs or
quartz plates inside
the handpiece of the
ultrasonic

10. PRINCIPLES OF ENDOSONICS
Tranducer element in endosonic transforms electrical energy of cavitron into acoustic
mechanical energy necessary to cause the vibration that energise the files and
diamonds
Resulting sound wave carry vibratory energy along the entire length of the instrument
and causes a reciprocal movement in these files/diamond
Energy wave enables instruments to remove debris, tissue or containment
Martin HO, Cunningham WA. Endosonic endodontics: the ultrasonic synergistic system. International dental journal. 1984
Sep;34(3):198-203.

11. CAVITATION
Generation of bubble which grows to a
critical point and then undergoes
implosion releasing shock waves and
tremendous force with a vaccum effect

12. During the low-pressure cycle, high-intensity ultrasonic waves
create small vacuum bubbles or voids in the liquid.
When the bubbles attain a volume at which they can no longer
absorb energy, they collapse violently during a high-pressure
cycle.

13. Sound waves that propagate into the liquid media
Alternating high-pressure (compression) and low-pressure (rarefaction) cycles
During the low-pressure cycle, high-intensity ultrasonic waves create small
vacuum bubbles or voids in the liquid
When the bubbles attain a volume at which they can no longer absorb energy,
they collapse violently during a high-pressure cycle.
Cavitation
During the implosion very high temperatures (approx. 5,000K) and pressures
(approx. 2,000atm) are reached locally. The implosion of the cavitation
bubble also results in liquid jets of up to 280m/s velocity

14. Vyas N, Dehghani H, Sammons RL, Wang QX, Leppinen DM, Walmsley AD. Imaging and analysis of individual cavitation
microbubbles around dental ultrasonic scalers. Ultrasonics. 2017 Nov 1;81:66-72.

15. ACOUSTIC
STREAMING
Small, intense circular fluid movement
around the instrument
Increase in shear stress

16. Ultrasonic tip vibration: 2 variables, the frequency (number of times the tip
moves back and forth every second) and power or intensity (the amplitude or
arc of the tip movement, which is usually operator controlled).
Water has always been inherent to ultrasonic use; being necessary in
magnetorestrictive units to cool the handpiece, the tooth surface, and the tip.
Piezoelectric units still require the use of water, for most endodontic
applications water is discretionary. For example, in access refinement and
chasing calcified canals, much dentinal dust is created.
 This, when mixed with water, tends to become a slurry that might bog
down the ultrasonic instrument, and will certainly obscure the clinician's
vision.
Iqbal MK. Nonsurgical ultrasonic endodontic instruments. Dental Clinics. 2004 Jan 1;48(1):19-34.

17. When using an ultrasonic tip to remove a metal post by vibrating it, the heat
generated can cause thermal injury to teeth and their supporting structures.
Ultrasonic tips that have water ports are preferred over tips without.
 The availability of a stream of air during ultrasonic use is also necessary.
 It also will act as a coolant, and a steady stream of precisely directed air
can help keep clear visibility, blowing away dentinal and other dust and debris
Iqbal MK. Nonsurgical ultrasonic endodontic instruments. Dental Clinics. 2004 Jan 1;48(1):19-34.

18. ULTRASONIC TIPS
•Smooth stainless steel, zirconium nitride, and diamond coated tips
diamond coated surfaces offer some of the best cutting efficiency.
• However, diamond particles can fall out and wear down rapidly, making
ultrasonic tips dull and much less efficient all too soon.
•BL tips, integrated sharp micro-projections (small raised bumps) on the tip
surface, which engage the tooth surface precisely and efficiently.
•The active abrasive surface has considerably more longevity than other coated
tips, and they are less expensive due to the lack of an additional coating
process.
Iqbal MK. Nonsurgical ultrasonic endodontic instruments. Dental Clinics. 2004 Jan 1;48(1):19-34.

19. ULTRASONIC TIPS
BL-1: A workhorse tip with 100-µm projections and a very sharp tip enables easy
penetration through calcification and obstructions, as well as for the removal of pulp
stones and gutta-percha.
• BL-2: more conservative and safe tip with the same tapered design, but with a rounded
cutting end and 50-µm projections, ideal for the removal of secondary dentin in the
search for elusive canals, and for de-roofing pulp chambers.
• BL-3: Slightly larger than the BL-2, with 50-µm projections at the end, and 100 µm on
the sides. This tip has a similar use to the BL-2: it is very efficient for removing and
planning pulp stones on the canal wall and in the chamber simultaneously
• BL-4: Floor polisher, this tip is a flat end-cutting tip, which effectively grinds down
pulp stones and irregular surfaces on the pulp chamber floor.
• BL-5: Longer tip with 50-µm projections, allowing it to reach where the BL-1 to -3 tips
cannot, ideal for the removal of the isthmus, coronal shaping, especially in ovoid shaped
canals, and the removal of canal obstructions
• BL-6: Traditional smooth surface tip used only for troughing around (not contacting)
posts, separated instruments, obturation carriers, silver points, etc.

20. TIPS
•Long slender,Short sturdy
•Simple curves, multiangled bends
•End cutting, side cutting
•Stainless steel or titanium alloy
•Stainless steel tips: may be coated with zirconium nitride or
diamond grit to increase efficiency and durability
•Either function dry or come with water ports for cooling and
cleaning of area
Iqbal MK. Nonsurgical ultrasonic endodontic instruments. Dental Clinics. 2004 Jan 1;48(1):19-34.

21. Stainless steel tips that are
effective and very
economical
To improve efficiency,
ultrasonic instruments
also have been
manufactured with a
coating of zirconium
nitride(ProUltra)(designe
d to function dry)

22. CPR tips: diamond coated
and have built-in water
ports
Diamond-coated tips:
last longer and are
associated with greater
efficiency when compared
to
uncoated or zirconium
nitride-coated tips

23. Both the CPR and
ProUltra
systems also are
accompanied by a set of
slender and long tips
made from
titanium alloys
Titanium : provides
flexibility and greater
vibratory motion to the
tips. These tips are end
cutting and are employed
for
cutting deep inside the
root canals

24. BUC: diamond coated
and have built-in waters
ports that
constantly bath the
activated tips

25. ‘‘4’’ series (Sybron
Endo): geared for
troughing around posts
and opening calcified
canals

26. short and sturdy tips: used for
vibrating posts out of root canals
are operated at medium-high
intensity
tips that are used for bulk removal
of dentine or restorative materials
(eg, CPR 2): used at moderate
to high intensities
Most common reason for breakage:
incorrect frequencies
slender and longer tips with small
cross-sectional diameters (ie, CPR
6–8): fracture easily when used at
high intensity
troughing tips (eg, CPR 3D–5D,
BUC 3, and CPR 6–
8): low intensity
Thick And Short Tips Are Operated At Higher Intensities, Whereas Long And Slender Tips Are
Operated At
Lower Intensities

27. If the instrument begins
to stall, contact with the
cutting surface should
be broken temporarily to
allow the tip to regain
its oscillations.
Shanks: different
lengths ranging from 15
mm to 27 mm
For greater control, the
shortest tip possible to
reach the desired depth
should be used
ultrasonic frequencies:
range 20 kHz to 30 kHz.
oscillation of tip may be
stalled if introduced in
narrow canals or
forcefully applied
against dentine or
restorative material

28. Access
Refinement
Tips
Vibratory Tips
Bulk Removal Tips
Troughing Tips

29. Example:
CPR 2D or
BUC 1
Access refinement tips
Greater control
Identification
of missed canal
Cavitation:
Disruption of
pulp tissue and
calcific deposits

30. Luting :
ZnPO4 easier
to dislodge due
to microcracks
compared to
resin cements
Vibratory tips
Removal of
posts
Example: VT,
CPR1
Tips:
Spherical or
flat

31. Remove
dentine and
core material
quickly
Bulk removal tips
sharp and
sturdy tips,
operated at
moderate or
maximum
intensity
Example: BUC1,
CPR2D
Diamond coated,
water port

32. Longer tip:
More chances
of fracture,
should be used
with light
touch
Troughing tips
CPR 3D,
4D, and 5D,
which are 15,
20, and 25
mm in length
BUC 3, CTR 4:
diamond
coating, remove
cement as well
as thin shelf of
dentin

33. Thanks!