1.
LASERS IN ENDODONTICS
INDIAN DENTAL ACADEMY
Leader in continuing dental education
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2.
INTRODUCTION
L A S E R – light amplification of stimulated
emission of radiation, is a form of
electromagnetic energy in which
photons are generated from a
medium by stimulating the
medium
from external energy source.
Emergence
: 1960
First use in clinics : 1980
Today available in different wavelengths.
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3.
ADVANTAGES
Excellent visibility.
 Reduced operating time.
 Reduced post operative sequelae.
 Negotiates curves and folds in oral cavity.
 Vaporize, coagulate or cut tissue.
 Pain is reduced 90% of the time.
 Portable and less expensive newer models
 Patient’s high acceptance .

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4.
HISTORY

Early 1900 – Quantum mechanics by Bohr
Einstein's atomic theory.

1950 – Townes first amplified microwave
frequencies.

1960 – Maiman developed first laser or Maser.

1960 – Pulsed Ruby laser(0.694 µm).

1961 – Neodymium laser by Snitzer.
HAD DENTAL RESEARCHERS FOCUSSED ON Nd.
LASER SOONER,
LASER DENTISTRY MAY HAVE PROGRESSED TO ITS
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PRESENT STATUS 10 YRS EARLIER

5.
EPIDEMIOLOGY

IN 1987 Mecler studied Co2 laser and found it
to induce secondary dentin formation and
sterilize dentin.

Nd:YAG Laser after apicoectomy and retrofil
reduced permeability of resected roots.
-Adam stabholz (1992).
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6.

CO2 Laser delivered by Agcl fibers in root
canal opened dentinal tubules and fused
hydroxyapatite.
Banu onal et al (1993).

Nd:YAG laser effectively inhibited the
growth of bacteria in root canal.
Steve E Fegan (1995).
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7.

Argon laser is efficient in removing intra canal
debris.
-Josjna Moshorow(1995).

Nd:YAP Laser in combination with hand
instruments is an effective device for root
canal preparation.
-Piesse frage et al(1998).
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8.

Er:YAG laser with a cone shaped tip gave
cleaner dentin surface in root canals, compared
to rotary instrumentation.
-Shigeru shoji (2000).

Apical leakage after obturation in canals
prepared with Er:YAG laser is not affected as
compared to canals prepared with
conventional methods.
-Y.Kimura (2001).
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9.
LASER PHYSICS

L ight A mplified by S timulated E mission of R
adiation.

LASER light is Monochromatic and finely focussed.

Collimation and Coherency makes it unique.

Collimation: constant beam size and shape.

Coherency: waves with identical amplitude and
identical frequency.
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10.
QUANTUM THEORY

An Atom at excited state releases photon.
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11.
EINSTEIN’S THEORY

An energized atom can absorb additional energy
to release 2 identical coherent photons, these
photons energizes more atoms and releases more
photons resulting in amplification of light energy.
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12.

Dental lasers have emission wavelengths of
500µm – 10,600µm.

All dental lasers emit either visible light beam or an
invisible infra red light beam.

Dental lasers are named after the chemical elements/
compounds that compose the medium.
- Gas
:- argon / co2
- Solid crystal rod :- Ga, Al, Arsenide,
Garnet, Yttrium,
-Added elements :- Cr, Nd, Ho, Erbium.
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13.
ANATOMY OF LASER UNIT

LASER CHAMBER IS CALLED – “CAVITY”.

M1 - PARTIALLY REFLECTIVE MIRROR.

M2 - TOTALLY REFLECTIVE MIRROR.

EXTERNAL SOURCE www.indiandentalacademy.com
OF ENERGY IS CALLED PUMPING.

14.
LASER DELIVERY SYSTEM

FLEXIBLE HOLLOW WAVE GUIDE TUBE
It has interior mirror finish.
Laser energy reflected along this tube strikes the tissue in non
contact fashion.

GLASS FIBER OPTIC CABLE
Glass fiber is encased in a resilient sheath.
Cannot be bent into sharp angle.
fiber fits snugly into hand piece protruding at the tip or sometimes
with attached glass tip.
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Used in contact fashion.

15.
EMISSION MODE
1. CONTINUOS WAVE MODE.
Beam is emitted at one power level
continuously as the foot switch is
pressed.
2. GATED PULSE MODE.
Periodic on and off by the
mechanical shutter in front of a
continuous wave laser at a
duration of few milli seconds.
3. FREE RUNNING PULSE MODE.
High energy of laser light is
emitted for a few micro seconds
followed by a relative long time
gap.
This is computer controlled.
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16.
PRINCIPLE OF EMISSION

Light energy strikes tissue for a certain length
of time producing thermal interaction, then a
time gap for the tissue to cool before the next
pulse of laser energy is emitted.
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17.
LASERS USED IN DENTISTRY
LASER
λ
LASER
λ
Argon
488-514 nm
Nd:YAP
1.34 µm
Diode
600-908 nm
Ho:YAG
2.12 µm
He-Ne
632 nm
Er:YSGG
2.79 µm
Ruby
694.3 nm
Er:YAG
2.94 µm
Nd:YLF
1.053 µm
CO2
9.3,10.6 µm
Nd:YAG
1.064 µm
XeF
0.351 µm
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18.
LASER SAFETY IN DENTAL PRACTICE

A Responsibility that is shared by a Dentist,
Educator, Manufacturer and scientist, each having a
role from design and development to practical
application.

Given the proper training and appropriate
precautions, lasers may be used safely for the mutual
benefit of both the patient and the dentist.
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19.

CDRH – Center for Devices and Radiological
Health.

ANSI – American National Standards
Institute.

OSHA – Occupational Safety and Health
Administration.
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20.
LASER HAZARD CLASSIFICATION
– ANSI & OSHA
CLASS
I
DESCRIPTION
Low powered lasers that are safe to view.
IIa
Low powered visible lasers that are hazardous when viewed
directly for longer than 1.000 sec.
II
Low powered visible lasers that are hazardous when viewed
for longer than 0.25 sec
IIIa
Medium powered laser or systems that are non hazardous if
viewed for less than 0.25 sec with out magnifying optics.
IIIb
Medium powered lasers (0.5 w) are hazardous if viewed
directly.
IV
High powered lasers(>0.5 w) produce ocular,skin and fire
hazards.
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21.
According to CDRH and ANSI system of classification CLASS
IV are Potentially Hazardous from either direct or diffuse
reflection.
They emit power greater than 5 w.
HAZARDS ENCOUNTERED IN CLINICAL PRACTICE
1. OCCULAR INJURY.
2. TISSUE DAMAGE.
3. RESPIRATORY HAZARDS.
4. COMBUSTION & ELECTRICAL HAZARDS.
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22.
LASER SAFETY OFFICER (L.S.O.)

Identifies and assess the Hazard .

Determines the potential hazard zone.

Establishes standard operating procedures.

Approves use of protective equipment.

Ensures safety of all persons within the operating
field.
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23.
SAFETY RECOMMENDATIONS

All class IV Dental lasers are potentially hazardous.
Manufacturer safety precautions must be followed.

Fire and electric hazards can be avoided by
• Dry floor.
• Soaking surgical drapes and gauze in sterile saline.
• Avoid flammable liquids and gases.

Personal protective equipment.
• Safety goggles
• Mouth masks
• High vacuum evacuation
• Re – circulatory air filter system
• Proper ventilation
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24.
LASERS IN ENDODONTICS
A. LASER DOPPLER FLOWMETRY.
He-Ne (λ=632.8) and Ga Al As (780-820)
Semiconductor diode lasers at 1 or 2 mw power are used.
Principal is based on the changes in the red blood cell flux
in the pulp tissue.
DISADVANTAGE.
• Difficult to obtain laser reflection in molar tooth.
ADVANTAGE.
•Painless diagnosis.
•Useful vital and non vital diagnosis of tooth.
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25.
B. HEAT TEST

Pulsed Nd:YAG laser can be used as an alternative to Hot
gutta-percha method.
ADVANTAGE.
Nd:YAG Laser induced pain is mild and tolerable.
 Pain response can be obtained in tooth with thick enamel and
dentin.
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26.
DIFFERENTIAL DIAGNOSIS OF PULPITIS
A. NORMAL PULP VS ACUTE PULPITIS.
▪
Nd:YAG laser at 2w power and 20 pulses/sec at a distance of 10
mm from the tooth surface, pain is produced within 20-30 secs
and disappears in a couple of seconds.
- NORMAL PULP.
▪
If pain is induced immediately after laser application and
continues for more than 30 sec after removing the stimulus.
- AUTE PULPITIS
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27.
ACUTE SEROUS PULPITIS vs ACUTE
SUPPURATIVE PULPITIS

If the Electric current resistance is greater than 15.1 mΏ
and patient experiences continuous pain for more than 30
secs.
- ACUTE SEROUS PULPITIS.

If the electric resistance is less than 15.1 mΏ and the
pain is continuous for more than 30 sec.
- ACUTE SUPPURATIVE PULPITIS.
INFERENCE:
Carious impedance of less than 15.1 mΏ indicates that
no hard healthy dentin exists b/w caries and Pulp
chamber.
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28.
DESENSITIZING HYPERSENSITIVE DENTIN


PULSED Nd:YAG laser is the choice.
Parameters : 1w, 20 pps at 2-3 mm distance and coating
the surface with black ink.
3 DIFFERENT APPROACHES.
1.Stimulating the mucosal surface.
• In Root hypersensitivity
• Duration - 10 sec.
• In mild hypersensitive cases.
2. Stimulating the crown portion.
• Tooth surface adjacent to sensitive area is exposed.
• 0.5 sec/exposure for 2-3 times.
3. Stimulating the surface of dentin.
• Sensitive dentin is directly exposed.
• Brings morphologic changes in dentin and stimulates central
pulpal neurons.
• In severe cases.
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29.
PULP CAPPING
A. INDIRECT PULP CAPPING.
Discovery of closure of dentinal tubules and sedative effects on
Pulpitis has led to the use of lasers in direct pulp capping.
• Deep hypersensitive cavities are indicated.
• Nd:YAG laser of 2w, 20pps for < 1 sec is used after coating
tooth surface with black ink and air spray cooling to prevent
pulp damage.
B. DIRECT PULP CAPPING.
CO2 Laser has shown 89% success due to
▪ Control of hemorrhage
▪ Sterilization and Carbonization.
▪ Stimulation of dental pulp cells.
• Irrigate the exposure site with 3% Naocl & 3% H2O2 for 5 min.
• CO2 irradiation is performed at 1 or 2 w for 5 min.
• CaOH is placed overwww.indiandentalacademy.com cavity sealed.
the exposed site and

30.
ROOT CANAL TREATMENT
ACCESS CAVITY.
Er:YAG and Er Cr:YSGG Laser which ablate
Enamel and Dentin can be applied at 5w and 6Hz
under water spray.
ROOT CANAL PREPARATION.
1. Laser tip must slide gently from the apex to the
coronal by gently pressing the tip against the
wall under water spray.
2. Er:YAG Laser at 8 Hz and 2w power.
3. Pulsed Nd:YAG at 2w power,20pps for 1sec
with 5 sec interval b/w pulses removes pulp
remnants, debris and stimulated apical cells.
4. Nd:YAG with 38% AgNH4 effectively killed
micro organisms.
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31.
PERIAPICAL LESIONS WITH SINUS TRACT
INDICATIONS.



CASES FOR WHICH APICOECTOMY OR PERIAPICAL
CURRETAGE CANNOT BE PERFORMED.
CASE WITH DEEP POST IN THE ROOT CANAL.
ADJUNCT TO STANDARD ENDODONTIC /SURGICAL RX.
LASER: PULSED Nd:YAG AND CO2.
PROCEDURE:
• AT 20W AND 20PPS THE LASER TIP IS INSERTED INTO
THE SINUS TRACT AT THE APEX AND DRAWN SLOWLY
TO THE OPENING OF SINUS TRACT.
• IT IS PERFORMED 3-4 TIMES DURING ONE VISIT AT 1 OR 2
VISITS PER WEEK TILL SINUS DISAPPEARS.
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32.
UNDER RESEARCH

APICOECTOMY, RETROGRADE CAVITY PREPARATION AND
PERIAPICAL CURRETAGE .
- Nd:YAG & CO2.

CLOSURE OF APICAL FORAMINA.

LASER RX WITH STEREO MICROSCOPE /FIBEROSCOPE.

- Pulsed Nd:YAG.
▪ TO REMOVE POLYPS, FRACTURED INSTUMENTS
DEBRIS, PULP REMNANTS, POST SPACE PREP’N
UNDER VISUAL FEED BACK.
ROOT CANAL SWEEPING AND IRRIGATION WITH CAVITATION.

STRENGTHENING ROOT CANAL WALL WITH AgNH4 SOLUTION &
LASER.

ROOT CANAL FILLING USING GUTTAPERCHA OR RESIN WITH
LASER.
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33.
STRENGTHENING ROOT CANAL TREATED
TOOTH

PULPLESS TEETH HAVE TENDENCY TO FRACTURE.

TEETH LASED WITH 38% AgNH4 SOLUTION BECAME
DIFFICULT TO FRACTURE.

Pulsed Nd:YAG , CO2 , AND ARGON LASERS CAN BE
USED.
PROCEDURE:
Laser irradiation is performed in combination with 38%
AgNH4 solution at 2-3 w for 20 secs under air cooling until the
tooth surface becomes silver and mirror like.
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34.
RANGE OF LASERS IN ENDODONTICS
LASER
INDICATION
HeNe , Diode
Laser Doppler vitality
CO2 , Nd:YAG
Deep Caries RX
Nd: YAG , CO2 , Ho:YAG
Sterilization of Root canals
CO2 , Nd:YAG
Vital pulp amputation
Nd:YAG , Excimer, Er:YAG
Root canal preparation
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35.
CONCLUSION

WITH THE NEED FOR,
▪ Fiber optic delivery system.
▪ Multitude wavelengths and pulse widths.
▪ Economical devices.
LASER TODAY OFFERS AN ENDODONTIST
NOT ONLY A WINDOW BUT A DOOR INTO
THIS HI-TECH, REWARDING AND
POTENTIALLY PROFITABLE ARENA.
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36.
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