laesers used in operative dentistry,dentistry advansment,dentistry,oparative dentistry,laesers

1. GOOD AFTERNOON

2. LASERS USED IN OPERATIVE DENTISTRY
GUIDED BY:
Prof. H.D.Adhikary Dept. of
Conservative Dentistry
Dr.R.Ahmed Dental College & Hospital

3. Introduction
History of lasers
Components of lasers
Types of lasers
Application of lasers in operative dentistry
Summary

4. Dentistry has advanced a lot.
Among various advances, one which have good
scope of improvement is the use of lasers in
dentistry.
Recent advances in laser technology will bring
revolution in dentistry.
Laser is an acronym for light amplification by
stimulated emission of radiation.

5. It was discovered by Shallow & Towns in 1958.
First working laser was built by Mailman of
Hughes research laboratories in 1960.
HISTORY OF LASERS IN DENTISTRY:
Vain used a ruby laser & reported extensive deep
destruction of carious tissue along with
melting of dentin.
Paghdiwala[U.S.A] in 1988,first time tested the
ability of Er:yag laser on dental hard tissue.
In 1997,Er:yag laser was cleared for marketing by
Food & drug administration of U.S.A.

6. There are 3 main parts of laser delivery system.
(1).LASING OR ACTIVE MEDIUM
•It is the material which is capable of absorbing
the energy produced by the external source
through subatomic configuration of its
component molecules & subsequently giving the
excess energy as photons of light.
•It can be solid, liquid or gas.

7. (2).ENERGY OR PUMPING SOURCE
•It is used to excite or pump the atoms in
lasing medium to their higher energy levels
that are essential for laser production.
•It can be electrical,thermal,chemical or
optical.
(3).OPTICAL OR RESONATING CHAMBER
•The lasing medium is located within the
optical chamber.
•It is a cylindrical structure with fully
reflecting mirror on one side & partially
reflecting mirror on other side--parallel
to each other.

8. •This arrangement allows reflection of photons
of light, back & across the chamber.
•It will result in production of intense photo
resonance within the medium.

9. 2 categories of lasers are used in medicine & dentistry
(1).HARD LESARS
- Longer wavelength
- Cuts the tissue by ablation.
- Used for tooth & bone applications.
(2).SOFT LASERS OR LOW LEVEL LASERS
- Low energy wavelengths
- Cuts tissues by coagulation,vapourisation & carbonisation.

10. - They are believed to stimulate circulation
& cellular activity & causes various effects
such as anti-inflammatory,vascular,muscle
relaxant,analgesia & tissue healing.
There are many types of lasers used in
dentistry, depending upon their active medium
(1).CARBONDIOXIDE LASER
- WAVELENGTH: 10.6um
- USES: SOFT TISSUES , DENTIN DESENSITIZATION
(2).ARGON LASERS
- WAVELENGTH: 488,514.5um
- USES: CURING , SOFT TISSUE DESENSITIZATION

11. (3).Nd:YAG [NEODYMIUM:YTTRIUM-ALLUMINIUM
GARNET] LASER
- WAVELENGTH: 1.064um
- USES: SOFT TISSUE DESENSITIZATION , ANALGESIA
TOOTH WHITENING , PERIODONTICS,
ENDODONTICS
(4).KTP[POTASIUM-TITANYL PHOSPHATE] LASER
(5).HELIUM-NEON[He-Ne]
(6).RUBY LASER
(7).EXCIMER LASER

12. (8).HOLMIUM[Ho]:YAG LASER
(9).ERBIUM[Er]:YAG LASER
- WAVELENGTH: 2.94um
- USES: HARD TISSUE
(10).ERBIUM-CHROMIUM[Er-Cr]:YSGG LASER
- WAVELENGTH: 2.79um
- USES: HARD TISSUE
(11).DIODE
- WAVELENGTH: 800-830um
- USES:SOFT TISSUE , PERIODONTICS

13. • Ablation of tissues by vapourisationPHOTO-
THERMAL
• Bio-stimulation by stimulated ATP
production.
PHOTO-
CHEMICAL
• Dehydration,burning & carbonization.PHOTO-
ACOUSTIC

14. Proteins begin to
degenerate
Vapourisation
Dehydration, burning
& carbonisation
60`
100`
200`

15. DIAGNOSIS OF DENTAL CARIES
(A).INFRARED LASER FLUORESCENCE
[DIAGNODENT]
- Diagnodent is an instrument, recently designed to
facilitate the detection of dental caries.
- Used for detection of caries on occlusal & smooth
surface.

16. (B).LASER INDUCED FLUORESCENCE
- Kutsch in 1992,illuminated carious & non carious tissue
with argon laser along with dark field photography.
- He reported that while illuminating, carious lesion
has clinical appearance of dark,fiery,orange-
red colour.

17. CARIES DETECTION

18. CAVITY PREPARATION WITH LASER
- NUMBER OF STUDIES HAVE BEEN PERFORMED FOR THE
USE OF Er:yag LASER FOR CAVITY PREPARATION.
- Results of studies says that little or no noticeable pulp
reaction is produced while preparing the cavity with
Er:yag laser.
- It is safe & can be used for cavity preparation.

19. CAVITY PREPARATION
WITH LASERS

20. Thermal energy absorption by
tissues
Water vapourisation & ablation
Carious lesions have more water
content & hence greater effect.

21.  A.)minimises patient fear of the drill.
 B.)no irritating sound like traditional drills.
 C.)the cavity with laser preparation appears
open,patent,fresh & devoid of all debris.
 D.)mono-infection with Enterococcus faecalis is
avoided - hence sterile cavity.
 E.)melts the dentin & blocks the tubules,thus
hydrodynamic theory of dentin sensitivity is
ruled out.

22. PREVENTION OF DENTAL CARIES WITH
LASERS
Laser can be used for prevention of dental caries.
Different types of lasers increases the resistance to dental
caries by reducing the rate of demineralization of substance
of enamel & dentin.
Argon laser alters the surface characteristics of enamel to
make it caries resistant.
-
-
-
-

23.  MECHANISM OF ACTION
Carbonate is lost from carbonated appetite mineral of
tooth during laser irradiation
Pulsed co2 laser irradiation interacts with the
phosphate group in dental materials
It gets preferentially absorbed & transformed
efficiently to heat
Carbonated hydroxyapetite in the surface & in the
immediate subsurface of enamel is heated at temp.
greater than 400`c
Carbonate is decomposed, leaving behind the a
hydroxyapetite like mineral that is less soluble

24. BLEACHING WITH LASERS
- Power bleaching is the term used for accelerated
in-office tooth whitening procedures, using laser or
Xenon plasma arc-curing light.
(A). ARGON LASER
- A true laser light is delivered to chemical agent.
- The action is to stimulate crystals in the chemical.
- No thermal effect, so less dehydration of enamel.
- The treatment time is 10sec. per application per tooth.
It is the advantageous for clinician & patient.

25. (B). DIODE LASER
- A true laser light produced from a solid state
source.
- It is ultra fast, taking 3 to 5 sec. to activate
bleaching agent.
- This type of lasers produce no heat.

26. PHOTOPOLYMERIZATION OF COMPOSITE RESIN
WITH LASER
- ARGON LASERS ARE USED FOR THIS PURPOSE.
- FOR POLYMERIZATION OF CAMPHORQUINONE
ACTIVATED COMPOSITE RESIN,THE ARGON LASER
INCREASES;
~ THE DEPTH OF CURE
~ THE DIAMETRIC TENSILE STRENGTH
~ ADHESIVE BOND STRENGTH
~ DEGREE OF POLYMERIZATION OF
MATERIELS.

27. REDUCES;
~ Acid solubility of surrounding enamel
Decreases the time of activation
Significantly.

28. (1).Minimal damage to surrounding tissues.
(2).Haemostatic effect by sealing blood vessels.
(3).Reduction of postoperative inflammation &
edema.
(4).Little postoperative scarring.

29. (5).Reduction in postoperative pain sensation
since nerve endings are blocked.
(6).Dressing & suturing is not required for
wound closer.
(7).Operating time is reduced.
(8).Sterilization of wound due to reduction in
in amount of microorg. exposed to laser
irradiation.
(10).Excellent wound healing.
(11).Laser exposure to tooth enamel causes
reduction in caries activity.

30. (12).Patient becomes free
of fear & anxiety.
(13).Advantageous for
medically compromised
patients,since no
medication is required
like antibiotics or pain-
killers.

31. DISADVANTAGESOF LASERS
(1).Laser beam could injure the patient or operator
By direct beam or reflected light, causing retinal
burns.

32. (2).It available only at
big hospital &
treatment is
very expensive.
(3).Specially trained
person is needed.

33. As the research on
use of laser in
dentistry is giving
bright results,
lasers are getting
more &
 more famous
among dentists.

34. Special thanks goes to:
a.) Dr. Soumen Pal
b.) Mr.Abhisek Chatterjee
c.) Mr.Nurul Hasan Mollah
d.)Mr.Tousif Ahmed