Lasers used in pediatric dentistry

1. BY-
DR. PARAS ANGRISH
PGT FINAL YEAR

2. CONTENTS
 Introduction
 History
 Fundamentals of lasers
 Commonly used lasers in pediatric
dentistry
 Application of lasers
 Protection
 Conclusion

3. INTRODUCTION
 Laser is an acronym, which stands for Light
Amplification By Stimulated Emission Of Radiation
 In 1960,Theodore Maiman, a scientist with the
HughesAircraft Corporation, developed the first
working laser device, which emitted a deep red-
colored beam from a ruby crystal.
Light shows, disc players
 Device that converts electrical/chemical energy into
light energy

4. Glossary
 ablation –The process of removing tissue with a laser through vaporization or
mechanical disruption.
 absorption – Specific molecules in the tissue known as chromophores absorb the
photons.The light energy is then converted into other forms of energy to perform
work.
 active medium –The laser component that actually produces laser light when
stimulated. Dental lasers use crystals, gas, or semiconductors as their active media.
 beam transfer hardware – Mirrors, optical fibers, or hollow wave guide hardware that
caries the laser beam from the machine to the handpiece.
 chromophore –The tissue component that absorbs the laser energy and converts it
into thermal energy.
 coherence –The tendency of laser light waves to travel with their peaks and valleys in
unison.
 continuous wave mode – A form of laser emission when the laser is on continuously.
 divergence –The tendency of the laser beam to spread outward once it exits the
handpiece. Divergence varies depending on the specific laser and hardware used.
 energy density –The amount of laser energy in an area of exposed tissue.

5.  Er,Cr:YSGG – Erbium, Chromium - dopedYttrium Scandium
Gallium Garnet crystal.
 Er:YAG – Erbium-dopedYttrium AluminiumGarnet crystal.
 free running pulsed mode – A form of laser emission where laser
light is emitted in discrete pulses with specific, measurable
temporal characteristics.
 gated wave mode – A form of laser emission where the beam is
blocked part of the time by a shutter device creating a pulsed laser
emission.
 laser – Light Amplification by Stimulated Emission of Radiation.
 millijoule – Measurement of energy.
 monochromatic – In laser science refers specifically to the fact that
lasers produce a single wavelength of light.
 Nd:YAG – Neodymium-dopedYttrium AluminiumGarnet crystal.
 optical pumping – Flash lamp stimulation of an active medium.
 output coupler – A semi-transparent mirror in the resonator that
the laser beam passes through into the beam transfer hardware.

6.  photobiomodulation –The process whereby laser energy is used
to stimulate positive clinical outcomes such as pain relief and
improved healing.
 power – Rate of doing work, measured inWatts.
 pulse duration –The amount of time a laser pulse is on, measured
in microseconds.
 reflection –When the laser beam bounces off the surface with no
penetration or interaction at all.
 resonator –The mirrored chamber surrounding the active medium
that helps to amplify the laser light produced.
 scattering –The tendency of laser light to bounce in multiple
directions once it enters tissue.
 stimulated emission –The process whereby the active medium is
stimulated by an external source of light or electricity to produce
laser light.
 thermal relaxation –The ability of tissue to absorb and dissipate
heat produced by pulsed dental lasers.
 transmission –When laser energy can pass through superficial
tissues to interact with deeper areas.
 watt – Power measurement of energy produced over time.

7. HISTORY
 1960-first laser
 1993 Nd:YAG Laser
 1993 Kinetic Cavity Preparation
 1994 CO2 Laser, Argon Laser
 1996 Laser welder
 1997 Nd:YAP Laser
 1998 Er:YAG Laser

8. Fundamentals of lasers
Light
Amplification
by the
Stimulated
Emission
of
Radiation

9. Light
 Form of electromagnetic energy
 Properties of laser
 Monochromatic
 Collimation
 Coherency
 Efficiency

10.  Monochromatic-Characterized by radiation
in which all waves are of same frequency and
wavelength.
 Collimated: all the emitted waves are
parallel and the beam divergence is very low.
This property is important for good
transmission through delivery systems.

11. A laser is a device that creates and amplifies a
narrow, intense beam of coherent light.
•Radiates light in random directions
at random times.
•A jumble of photons going
in all directions.
Single or just a few frequencies
going in one
precise direction
LASER NEON LIGHT
COHERENT INCOHERENT

12.  A- Amplification means that a very bright
intense beam of light can be created. The
laser may be activated by a few photons
which then act to produce many more,
and the initial light generated is computed
to make a very bright compact beam

13. S – Stimulated : ME-Emission
 If an atom in the excited state is struck by a
photon of identical energy as the photon to be
emitted, the emission could be stimulated to
occur earlier than would occur spontaneously.
This stimulated interaction causes two photons
that are identical in frequency and wavelength to
leave the atom.

14. Laser Design
 A laser medium or active medium-solid,
liquid or gas
 Housing tube or optical cavity
 External power source-pumps

15. Components of laser
1. Active Medium
 The active medium may be solid crystals such as ruby or Nd:YAG, liquid
dyes, gases like CO2 or Helium/Neon, or semiconductors such as GaAs. Active
mediums contain atoms whose electrons may be excited to a metastable
energy level by an energy source.
2. Excitation Mechanism
 Excitation mechanisms pump energy into the active medium by one or
more of three basic methods; optical, electrical or chemical.
3. High Reflectance Mirror
 A mirror which reflects essentially 100% of the laser light.
4. PartiallyTransmissive Mirror
 A mirror which reflects less than 100% of the laser light and transmits the
remainder.

16. 16
Lasing Action Diagram
Energy
Introduction
Ground State
Excited State
Metastable State
Spontaneous
Energy
Emission
Stimulated
Emission of
Radiation

18. Laser Light Delivery
 Articulated arms-CO2 laser
 Waveguide delivery system
 Fiber optic delivery system

19. Laser Types
 Based on wavelength
-Soft lasers
-Hard lasers- MORETHAN 3000NM range
 Based on the type of active / lasing medium used
 (Gallium arsenide (GaAs), gallium-aluminum-arsenide (GaAlAs))-diode laser
655,810-980 nm
 ArF excimer, KrF excimer, XeCl excimer, Argon ion, Nd:YAG,Er:YAG, CO2
Types of Dental Lasers
 The dental lasers in common use today are Argon,
Erbium, Nd:YAG, Diode, and CO2. Each type of laser
has specific biological effects and procedures
associated with them. A solid understanding of each
of these categories of devices is imperative for any
clinician hoping to pursue laser use in their practice.

20. ERBIUM LASERS
 Erbium lasers are built with two different crystals, the
Er:YAG (yttrium aluminum garnet crystal) and Er,Cr:YSGG (
chromium sensitized yttrium scandium gallium garnet
crystal).They do have different wavelengths, Er:YAG has
2940 nm and Er,Cr:YSGG has 2780 nm.
 The erbium lasers are hard and soft tissue capable and have
the most FDA clearances for a host of dental procedures.
Their primary chromophore is water, but hydroxyapatite
absorption occurs to a lesser degree. Photothermal
interactions predominate in soft tissue procedures and
photodisruptive in hard tissue procedures.Thermal
relaxation is excellent and very little collateral thermal
damage occurs in tissues when proper parameters are
followed.

21. Nd:YAG laser
 Nd:YAG lasers were the first types of true pulsed
lasers to be marketed exclusively for dental use
in 1990. 1064 nm
 This wavelength is absorbed by pigment in the
tissue, primarily hemoglobin and melanin.
Photothermal interaction predominates and the
laser energy here can penetrate deeply into
tissues.
 Contact and non-contact mode
 Excellent biostimulation at 650 m sec pulse
especially for fibrin.

22. Diode laser
 Diode Lasers
 Diode lasers are becoming quite popular due to their compact
size and relatively affordable pricing. A specialized
semiconductor that produces monochromatic light when
stimulated electrically is common to all diode lasers.
 Contact or non contact mode
 Pulsed or continuous mode
 805-1064 nm
 655 for diagnodent
 The chromophores are pigments such as hemoglobin and
melanin, similar to the Nd:YAG absorption spectrum.
 Biostimulation
 Bleaching
 Antibacterial effect

23. Co2 laser
 CO2 Lasers have been available in medicine since
the early 1970’s and have been used in dentistry for
more than 25 years.They are a 10,600 nm infrared
wavelength, which is highly absorbed by water.
 The CO2 gas is in a chamber with nitrogen and
helium and the active medium is pumped with an
electrical current.
 10600nm
 Superpulsed gated continuous mode
 Improved hemostatsis and less charring of tissues
 9300 nm hard tissue co2 laser is also available now

24. Argon laser
 The argon laser is an alternative light source that can be used for
the photopolymerization of resin-based dental materials and for
tooth bleaching.The argon laser emits specific laser lines with
wavelengths that correspond to the absorption peak of
camphoroquinone, the initiator of polymerization for the
adequate photocuring of resin composite.The collimated beam
of the argon laser does not decrease with distance and an optical
fiber has access to all cavity areas. In addition, the temperatures
produced by an argon laser when curing resin-based materials
and performing in-office tooth bleaching are significantly lower
than those of conventional photocuring units. Argon is one of the
three dental laser wavelengths that have been cleared by the
FDA for tooth whitening.
 488 nm, which is blue in color, and 514 nm, which is blue green

26. Nd:YAG laser

27. DIAODE LASER
SEMICONDUCTOR LASER
GalliumArsenide chip
No mirror to clean and align
No gas tube, flashlamps,
laser rod, water cooling
Portable
No special power
No cooling connection
No heat
Quiet
Affordable
More powerful, less traumatic
250microsecond-10sec
0.05 Hz - 200 Hz
Expand Practice* Sulcular debridement
* Root canal treatment

28. Laser interaction with biologic
tissues
 Four different interaction
 Reflection
 Scatter
 Absorption
 Transmission

30.  Biological effects that can occur once the
laser photons enter the tissue:
 Fluorescence-DIAGNODENT 655NM
 Photothermal
 Photodisruptive / photo acaustic ablation
 Photochemical or photobiomodulation.

31.  When a laser heats oral tissues certain
reversible or irreversible changes can occur:
 • Hyperthermia – below 50 degrees C
 • Coagulation and Protein Denaturation – 60+
degrees C
 •Vaporization – 100+ degrees C
 • Carbonization – 200+ degrees C

33. Analgesic effects of laser/BIOSTIMULATION
Stimulation of any point of the body creates neural impulses that are transmitted to upper
nervous centers by neurons that have different features. These impulses finally reach the CNS.
Low-power lasers can leave their effects in different parts of the body. Currently the following
analgesic effects are recognized:
1.Low-power lasers inhibit the release of mediators from injured tissues. In other words, they
decrease concentration of chemical agents such as histamine, acetylcholine, serotonin, H+ and
K+ ,all of which are pain mediators.
2.Low-power lasers inhibit concentration of acetylcholine, a pain mediator, through increased
acetylcholine esterase activity.
3.They cause vasodilatation and increase blood flow to tissues, accelerating excretion of secreted
factors. On the other hand, better circulation leads to a decrease in tissue swelling.
4.They decrease tissue edema by increasing lymph drainage. They also remove the pressure on
nerve endings, resulting in stimulation decrease.
5.These lasers decrease sensitivity of pain receptors as well as transmission of impulses.
6.They decrease cell membrane permeability for Na + and K + and cause neuronal
hyperpolarization, resulting in increased pain threshold.
7.Injured tissue metabolism is increased by electromagnetic energy of laser. This is induced by
ATP production and cell membrane repolarization.
8.Low-power lasers increase descending analgesic impulses at dorsal spinal horn and inhibit
pain feeling at cortex level.
9.Low-power lasers increase the urinary excretion of serotonin and glucocorticoids, increasing
the production of β-endorphin

34. Advantages
 No anesthesia, no drill
 Less blood loss, Less pain
 Reduce post –operative edema
 Early healing, rapid regeneration, reduce post
sensitivity in restorations
 Less chances of metastasis
 Sterilization of treatment site-no infection

35. Disadvantages
 Lasers can't be used :
- fill cavities located between teeth
- cavities around old fillings and large cavities
(crown)
- remove defective crowns or silver fillings
- prepare teeth for bridges
 Laser - more expensive

36. APPLICATIONS-GENERAL
 Eye surgery
 Cancer treatment
 Removal of tattoos
 Cosmetic surgery
 Hair removal
• Cold Sores
• Nerve Regeneration
NO PAIN

37. Future Trends in Dentistry

38. Laser Procedures
 There is not a discipline in dentistry where lasers are not
helpful. Examples in each discipline will be presented
including the following:
 • Laser assisted caries diagnosis and management
 • Restorative dentistry
 • Surgical applications of dental lasers
 • Oral diagnosis/oral medicine
 • Oral surgery
 • Periodontics – gingivectomy, crown lengthening,
periodontitis treatment
 • Pediatric – restorative, frenectomy
 • Endodontics
 • Biostimulation

39. BLEACHING
SMILE

40. Crown lengthening

41. Soft tissues
Frenectomy
 Tongue tie
 Incisional and excisional biopsies
Inflammatory papillary hyperplasia

42.  Aphthous ulcer
 Operculectomy
 Removal of hyperkeratotic lesions
 Removal of malignant lesions
 Soft tissue crown lengthening
 Vestibuloplasty
 Removal of granulation tissue
 Removal of vascular lesions-Hemangioma
 Pyogenic granuloma
 Implants – Stage II – at the time of recovery

43. Laser Gingivectomy
 A Gingivectomy is a periodontal surgery that removes and
reforms diseased gum tissue or other gingival buildup
 Performed in a dentist's office, the surgery is primarily
done one quadrant of the mouth at a time under local
anesthetic.
 CO2 laser with wavelength of 10,600nm

44. GINGIVECTOMY

45. FRENECTOMY

46. Removal of inflammatory
hyperplasia

47. Why Fiberoptic is important?
 1. Light weight
 2. Easy to approach
 3. Easy sterilization
 4.Tactile sensation

48. 48
Laser Hazards

49. 49
Types of Laser Hazards
1. Eye : Acute exposure of the eye to lasers of certain wavelengths
and power can cause corneal or retinal burns (or both). Chronic
exposure to excessive levels may cause corneal or lenticular
opacities (cataracts) or retinal injury.
2. Skin : Acute exposure to high levels of optical radiation may cause
skin burns; while carcinogenesis may occur for ultraviolet
wavelengths (290-320 nm).
3. Chemical : Some lasers require hazardous or toxic substances to
operate (i.e., chemical dye, Excimer lasers).
4. Electrical : Most lasers utilize high voltages that can be lethal.
5. Fire :The solvents used in dye lasers are flammable. High voltage
pulse or flash lamps may cause ignition. Flammable materials
may be ignited by direct beams or specular reflections from high
power continuous wave (CW) infrared lasers.

50. 50
Lasers and Eyes
 What are the effects of laser energy on the eye?
 Laser light in the visible to near infrared spectrum (i.e.,
400 - 1400 nm) can cause damage to the retina
resulting in scotoma (blind spot in the fovea).This
wave band is also know as the "retinal hazard region".
 Laser light in the ultraviolet (290 - 400 nm) or far
infrared (1400 - 10,600 nm) spectrum can cause
damage to the cornea and/or to the lens.
 Photoacoustic retinal damage may be associated with an
audible "pop" at the time of exposure.Visual
disorientation due to retinal damage may not be
apparent to the operator until considerable thermal
damage has occurred.

51. 51
Laser Class
The following criteria are used to classify lasers:
1. Wavelength. If the laser is designed to emit
multiple wavelengths the classification is based on
the most hazardous wavelength.
2. For continuous wave (CW) or repetitively pulsed
lasers the average power output (Watts) and
limiting exposure time inherent in the design are
considered.
3. For pulsed lasers the total energy per pulse
(Joule), pulse duration, pulse repetition
frequency and emergent beam radiant
exposure are considered.

52. 52
Control Measures and Personal
Protective Equipment

53. 53
CONTROL MEASURES
Engineering Controls
 Interlocks
 Enclosed beam
Administrative Controls
 Standard Operating Procedures (SOPs)
 Training
Personnel Protective Equipment (PPE)
 Eye protection

54. 54
Common Laser Signs and Labels

55. Eye Protection – The patient, clinical staff and any
observers must wear protective eyewear specific for
the wavelength being used.
• Plume Control – Laser procedures create a
plume that may contain hazardous chemicals and
microflora. Standard dental high-speed evacuation
properly used is adequate to control the plume.
Good quality masks need to be worn by the
clinicians.
• Sharps – Scored laser tips of quartz fibers are
considered sharps and need to be disposed of as
such.
• Warning Sign – Warning signs need to be in a
visible place and access to the operatory limited.

56. LASER FILTRATION MASKS
prevents air borne contamination
FOOT PEDAL CONTROL SWITCH WITH PROTECTIVE HOOD
prevents accidental depression by surgical staff.

57.  Lasers - alternative to conventional surgical systems
 Lasers are a “new and different scalpel” (optical knife, light
scalpel)
 Dental lasers are now well established instruments.
Ongoing research is showing the many benefits of laser
therapy.The ability to perform less invasive procedures
with greater patient comfort makes laser dentistry
something the modern practitioner should consider. A
thorough understanding of laser physics and biological
effects is mandatory for any provider. Comprehensive
beginner and ongoing training is imperative to use these
devices effectively and safely.