LASERS IN ENDODONTICS AND CONSERVATIVE DENTISTRY

An acronym for Light Amplification by

the Stimulated Emission of Radiation..

A device that creates a uniform and

coherent light that is very different from

an ordinary light bulb.

dr. Blagoja Lazovski 2

Also can be described as a device for

generating a high-intensity, ostensibly

parallel beam of monochromatic(single

wavelength) electromagnetic radiation.

Laser light can be focused down to a

tiny spot as small as a single wavelength.


The possibility of stimulated emission

predicted by Einstein-1917..

Based on work of Gordon in 1955 & Schawlow n Townes in 1958, MAIMAN

created the 1st operatinal laser in 1960, a

ruby laser emitting a brillant red beam of

light..


photo of the development of the helium-

neon laser taken at AT&T's Bell

Laboratories in 1964.


Basic components..

An ACTIVE LASING MEDIUM :-

- cn be a solid, liquid or gas

Enclosed within a LASER CAVITY

bounded by two perfectly parallel

reflectors(mirrors)

PUMP SOURCE – high energy radiation

pumped into the active medium


POPULATION INVERSION :-

condition when energyfrom pump

source is absorbed by active medium

until the majority of atoms, ions or

molecules are raised to their upper

energy state..

And this condition is NECESSARY to

generate laser light..


TWO PARALLEL REFLECTORS – situated at end of laser cavity act to constarin light along n within the axis of cavity..

So light is repeatedly bounced b/w the reflectors

One of the mirrors is only partially reflective, enabling some of the light to escape the cavity as a beam of laser light..


Working of laser


Working of laser


Processing of matter without contact.

High working speed

Outstanding precision


Soft, quiet, vibration-free operation

As fast as the high-speed turbine

CO2 laser cuts and coagulates soft tissue without bleeding

No risk of cross-infection


Sterilization of operating field

Fewer cracks than with turbine

Multiple quadrant dentistry

No need for etching

Pulsing minimizes charring and thermal necrosis


Lasers are still in the pioneering stage, but

there are many current uses..

There are three types of Dental lasers:

Surgical Laser (soft tissue)

Curing Laser

Tooth Laser (hard tissue)


This laser replaces traditional surgery for many gum and soft tissue dental applications and is gentler than traditional surgical procedures.

This laser used for : Improve treatment

results for gum disease

Contour gums for smile enhancement

Surgically correct oral abnormalities


Surgically assist in arresting herpes lesions

and canker sores

Assist in biopsies

Treat infant tongue/frenum problems which

can hinder proper chewing/sucking

Treat child/adult frenum problems which

can cause speech impediments, gum

disease, and teeth to grow apart rather

than together


This laser spectrum light source is used for rapid teeth whitening and placing all tooth-colored restorations (fillings) and repair procedures.

Bonds created by this advanced instrument result in dentistry that is twice as strong !


The light source increases gradually during

the curing process to create the best bond

available in dentistry today.

Appointment length is also reduced

because it is 500% more powerful than

standard equipment.

Less than 1% of dental offices nationwide

have this instrument, making it one of the

newest tools in dentistry..


TOOTH LASER (hard tissue) Third type of laser is used to remove cavities. But since this laser cannot be used on existing metal fillings, we use micro dentistry..

MICRO DENTISTRY one of the greatest advancements in the field of dentistry.

offers the ultimate flexibility and capability. It is also the most tooth conservative dentistry available.


About 50% of cavities are candidates for this technique and there is no drilling, no needle, no extra fee, and no pain!

And because this process is so efficient, it reduces appointment length.


Desensitize exposed root surfaces

Diagnosis of non-cavitated caries

To arrest demineralization and promote

remineralization of enamel.

Debond ceramic orthodontic brackets.


The DIAGNOdent can find cavities that

other dental instruments can miss.

The device is designed as an adjunct to a

traditional oral examination in the

detection of occlusal decay. Teeth that are

suspicious for caries are ideal candidates

for survey with the device


Key Benefits:

A laser examination tool for the early

detection of caries.

Even very small lesions can be detected

at the earliest stages.

Over 90% accurate!

Earlier treatment - Better outcomes


Diagnodent is a pen-like probe that sends a safe, painless laser beam into the tooth. A numeric display & alarm signals when there are signs of hidden decay.



These pictures show how the Diagnodent

finds cavities that other

dental instruments can miss.


The Diagnodent device measures laser fluorescence within the tooth structure.

As the incident laser light is propagated into the site, two-way hand-piece optics allows the unit to simultaneously quantify the reflected laser light energy.

At the specific wavelength that the device operates (655 nm), clean healthy tooth structure exhibits little or no fluorescence, resulting in very low scale readings on the display.

Carious tooth structure exhibits fluorescence, proportionate to the degree of caries, resulting in elevated scale readings on the display


Roughen tooth surfaces ,in lieu of acid

etching in preparation for bonding

procedure




Treatment of dentin hypersensitivity..

In bleaching

Adhesion of pit & fissure sealant

Most obvious application – controlled

removal of dental enamel, dentin, bone or

cementum.

Replacement of dental drill is a real

possibility for the future. dr. Blagoja Lazovski 31

1968 – use of carbon dioxide laser – in oral and maxillofacial surgery – Goldman et all.

Restricted mostly to incising and excising masses from the mucosa and gingiva in oral cavity.

Vaporize exces tissue as in gingivoplasty, gingivectomyy and labial /lingual frenectomy.


Remove or reduce hyperplastic tissue.

Remove and control hemorraging of

vascular lesions such as hemangiomas.

In endodontics


LASER

TYPE

WAVEL

ENGTH

SPECTRAL

REGION MODE TYPICAL

MAX

POWER

CO2 10,600nm Mid-infrared

CW& Gated &superpulsed

100w CW

Holmium

2,100 nm

Near infrared

Pulsed 15Wavg.

Nd:YAG 1,064 nm

Near infrared

CW & pulsed

100W CW


Diode 800-890nm

Near infrared

CW >50W

KTP/KDP

532nm visible Pulsed 25Wavg.

Argon 488/514nm

Visible CW 20W

Excimer ArF-XeCl

190nm Ultaviolet

Pulsed 550mJ

Erbium:YAG(Er:YAG)

308nm Ultraviolet

Pulsed 250mJ


Co2 gas as lasig /active medium

Delivery system – uses an articulated arm (a

series of hollow tubes connected together

through a series of six to eight articulating

mirrors).

USED-

cutting & vaporising tissue in open

proceures or in procedures where rigid endoscopyis acceptable..


Efect of ruby laser radiation on enamel –

Goldman, Stern & Sognnaes, 1964

Carbondioxide laser – Lobene et all 1968

Nd:YAG laser – Yamamoto & Ooya 1974

Argon laser – Goodman & Kaufmann

1977


In removal of enamel n dentin – thermal

side effect occoured..

Superpulsed carbon dioxide laser – removal

of dentin without thermal side effect

possible.

Transversal stimulation or carbon dioxide

TEA (the Alexandrit laser with double

frequency) – most efficent carb.dioxide

laser for dental hard tissue ablation.


Clinical perespactive of lasers increased

by introduction of Er:YAG, Er, Er:YSGG

lasers

have advatages of

- reduced thermal effects

- creating precise contour of

the section zone.


Also in meantime new lasers

-Nd:YAG

-excimer

-holmium

-argon

-diode


In thermomechanical , micro-abrasion

like explosion – much less energy is

needed.

If soft tissue is softened by caries,the laser

ablation rate increases…

Rough surfaces produced by laser

ablation provide good retension


Dentin surfaces r less rough aftr ablation

and hence less problamatic.

High bond n shear strength can be

achieved with simple defocused

radiation..

For conditioning less time is needed than

when etching conventionaly..


Drying the surface with laser is very quick , efficent and gentle.

Erbium laser has bactricidal abilities.

Bcz high surface temperature can be achieved for a short time by subalative irradiation..

Irridation of caries by a sequence of laser pulses leads to consecuetive dessication and sterlization.


The Er:YAG laser can be used to disinfect

cavity prep , in case of residual bacteria

contaminating, otherwise intact enamel

or dentin, or in fissures prior to sealing.


Best results obtained whn affected areas

exposed to co2 , Nd:YAG, Er:YAG, Diode

laser radiation

Colojoara et al showed that dentin

hypersensitivity can be reduced without

any damages to pulp vitality by using co2

laser..

They also showed that when using co2 laser

, in parallel direction with dentin tubules, the

desensiting effect ws obvious aftr three

exposures. dr. Blagoja Lazovski 45

The first materials introduced in 1970’s

(photopolymerised composites) wr

cured by ultraviolet light..

Power et al showed that an argon laser

requires shorter curing times & th

ematerials dentin bond strength was

stronger whn compared with laser.


Variables that control the depth &extent

of cure include

- time of exposure

- composite material

- wavelength

- intensity of light

- particle size of filler


Current reserches report that used at the

power of 250 +/- 50 mW for 10sec per

increment ,

the argon laser provides good curing of

light activated restorative material in

shorter period of time with equal or

better physical properties than the

conventional halogen curing light..


With today's technology, laser teeth whitening through the use of the Diode Laser is the quickest and most dramatic way to brighten your smile if porcelain laminates are not an option.

All tooth whitening procedures use hydrogen peroxide or carbamide peroxide to bleach out stains on your tooth enamel, but this is where the similarity ends when comparing standard bleaching procedures such as whitening performed with a light cure to laser whitening.


Laser whitening is superior to all other whitening techniques since

1.laser whitening products contain the highest concentration of peroxide 2.the laser provides the highest light intensity available 3.the procedure is done in the office at chairside

thus allowing us to concentrate in those areas of your mouth where the type and location of discoloration is worse. Laser technology allows us to whiten your teeth with amazing results in just one hour!


1.the type of stain on your teeth

2.where the stain is located

3.the amount of time the whitening gel is used

4.the peroxide concentration in the whitening gel

5.the intensity of the light activating the whitening gel


In Laser-Assisted Tooth

Whitening, the laser enhances the effect of bleaching agents for faster, more comfortable and more effective results.

By stimulating the bleaching gel to react faster, the bleaching agent (mainly peroxide) spends less time on the tooth.

This leads to increased comfort levels, a reduction in reaction from gums both during and after treatment, and improved results over non-


Types of hazards

Ocular hazards

# injury to eye – direct emission or by reflection from mirror like surface.

# irreversible retinal burns- by conversion of incident radiation to heat energy.


* damage to skin & other non-target tissue

result from thermal interaction of energy

with tissue proteins

* temperature elevations can produce

denaturation of cellular enzymes

&structural proteins which interrupt basic

metabolic processes


Are referred to as non-beam hazards

Capable of producing smoke , toxic

gases and chemicals.

Laser plume – composed of vaporised

water (steam), carbon particles, cellular

products..


The greatest producers of smoke are

co2, erbium lasers followed by Nd:YAG

Lasers..


High energetic & short pulsed laser light

lead to a fast heating of dental tissue.

Energy dissipates explosively in vol of

expansion – accompanied by fast

shockwaves..

The shockwaves lead to high pressure –

destroy or damage adjacent tissue.


Characteristically pulp tissue cannot

survive environment of elevated temp

for protracted periods when tooth

structure is irridated with lasers.

Use of combination of air and water

spray before during or immediately after

laser irridation may be more effective..


Flammable solids , liquids, gases used

within the surgical setting can be easily

ignited if exposed to laser beam..


Can be in form of

- electric shock

- fire

- explosion


Temperature < 60 celcius

~ tissue hyperthermia

~ enzymatic changes

~ edema

Temperature > 60 celcius

~ protein denaturation


Temperature < 100 celcius

! Tissue dehydration

! Blanching of tissue

Temperature > 100 celcius

! Super heating

! Tissue ablation&shrinkage


Operatory must be dry

Control panel & its electrical power unit

should be protected from any kind of

splashing..


Can cause charring

Coagulation of blood elements


Highly reflective instruments & those with

mirror surfaces should be avoided.

Tooth protection is needed, whenever ,

the beam is directed at angles other

than parallel to the tooth surface.

A no.7 wax spatula can be inserted into

gingival sulcus to serve as an effective

shield for teeth


If anesthesia is required in place of

standard PVC tubes , rubber or silastic

tubes should be used.

For further protection tube should be

wraped with an aluminium tape.




The plume from a

laser ablation

deposition:

A Nd:YAG laser

hits ZnTe


The 514nm line of

the cw laser, a

few 100 mW,

going through a

prism. Do not try

this at home!


Figure 1A—

Maxillary left first

permanent molar

with occlusal

enamel

hypoplasia


Figure 1B—Waterlase MD.

used to remove

(ablation).


Completed cavity

preparation after

using Waterlase

MD


Completed

restoration with

resinomer



Thank You

Date post:	12-May-2015
Category:	Health & Medicine
Upload:	blagoja-lazovski
View:	8,705 times
Download:	17 times

LASERS IN ENDODONTICS AND CONSERVATIVE DENTISTRY

Health & Medicine