lasers in orthodontics

LASERS IN ORTHODONTICS

GUIDE SMT DR CHANDRALEKHA

PROFESSOR AND HEAD OF DEPARTMENTDEPARTMENT OF ORTHODONTICS

VYDEHI INSTITUTE OF DENTAL SCIENCES

PRESENTED BY DR OMAR RIZVI

POST GRADUATE STUDENT DEPARTMENT OF ORTHODONTICS VYDEHI INSTITUTE OF DENTAL SCIENCES

• SPECIAL THANKS TO SHRI DR VENKETESHIAH

PROFESSOR OF DEPARTMENT OF ORTHODONTICS

SMT DR ROOPA

SR LECTURER

DEPARTMENT OF ORTHODONTICS

SHRI DR VINOD

SR LECTURER

DEPARTMENT OF ORTHODONTICS

L light A amplified by S stimulated E emission of R radiation

LASER is a device that transforms a light of various frequencies into chromatic radiation in the visible, infrared and ultraviolet regions, with all the waves in phase capable of mobilizing immense heat and power when focused at a close range

Historical perspective

• Early 1900s-chinese and egyptians (phototherapy)

• 1960 Thiodore Maiman• 1965 Dr Goldman• 1970s nd-YAG• 1982- Pick Frame and Picaro• 1987 Meyers portable laser

• Stern and sognnaes(1964) and Goldman et al (1964) were the first to investigate potential uses of ruby lasers in dentistry

• They began their studies on dental hard tissue by investigating the

possible use of a ruby laser to reduce surface dimeralisation.

HISTORYHISTORY

• 1991 1991 Soft LaserSoft Laser

• 1993 1993 Nd:YAG LaserNd:YAG Laser

• 1993 Kinetic Cavity Preparation1993 Kinetic Cavity Preparation

• 1994 CO1994 CO22 Laser, Argon Laser Laser, Argon Laser

• 1996 Laser welder1996 Laser welder

• 1997 Nd:YAP Laser1997 Nd:YAP Laser

• 1998 Er:YAG Laser1998 Er:YAG Laser

FUNDAMENTALS OF LASERS

• Light beam is composed of packets of energy known as photons

• Ground state-atoms are normal state• Atoms are excited by energy and move to higher energy• As it reverts back to its ground state, energy is emitted-

spontaneous emission• Results without external interference and forms waves

that are in phase.• With all the various types of lights and materials on the

market, it is virtually impossible to come up with one protocol, especially one featuring reduced curing times,across the board.

Curing Lights

• Curing lights allow us to polymerize “on demand” a vast array of materials.If you undercure a restoration, for example, you may not even be aware of the negative sequelae for years. Using a light that puts out too much energy also continues to be a topic for discussion. Therefore,selecting a curing light and using it properly can greatly affect the performance and longevity of your restorations.

Types of Curing Lights

• Halogen Use a halogen bulb as the source of light.• + Most common• + Least expensive• + Reliable• + Long track record• + Should cure all materials • + Available in corded and cordless models• + Wide bandwidth (400nm-510nm)• – Somewhat slower than plasma arc and argon lasers

• Plasma Arc Bulb is really an aluminum oxide, high pressure vessel, which contains highly energized xenon gas (plasma) under 150psi. The inside shape is specific to reflect light arcing between two electrodes. Arc is only about 1mm long, enabling a very focused beam.

• + Very fast

• – Expensive

• – Larger than halogen

• – Limited track record

• – May not cure all materials

• – Tips are usually too small for most restorations

• – Cords are liquid-filled, may be stiff, and can degenerate over time

• Argon Laser Light generated when energy is applied to an atom raising an electron to a higher, unstable energy level. Electron will return to stable level by releasing light through a medium of argon gas.

• + Fast• – Tips are usually too small for most restorations• – Very expensive• – Larger than halogen• – May not cure all materials

• LED (Light Emitting Diode) Special diodes (an electronic device that restricts current flow chiefly to one direction) that emit light when connected in a circuit.

• + Available in cordless and corded• + Light in weight• + Small• + Long battery life due to the low power usage• + Virtually no heat generation at the tip• – New, very limited track record• – May not cure all materials• – Most have poor selection of tips• – Power output questionable

Curing Modes

• High or Boost Usually the highest power the light will generate.Achieves this power within five seconds of activation.Entire curing interval will be at this level power. Typicallysynchronized to a timer that has a 10-second curing interval,which may not be adequate for many restorations.

• Regular or Normal Medium power level.Will usually cureall types of restorations — just a little slower than high power.

• Step Cure at low power (usually about 150mW/cm2) for 10seconds, followed by an instant “step up” to a much higherpower (usually maximum of light) for the rest of the curinginterval.

• Ramp Start curing at low power (usually about150mW/cm2), followed by a linear increase to a higherpower (usually maximum of light) for 10 seconds, and then stay at that high level for the rest of the curing interval.

• Pulse Has different meanings for different lights, but usually means either the power cycles between high and low every second or so or the power cycles on and off every second or so from the beginning of curing.

Nd: YAG laser

DIAODE LASERDIAODE LASERSEMICONDUCTOR LASER

Gallium Arsenide chipGallium Arsenide chipNo mirror to clean and alignNo mirror to clean and alignNo gas tube, flashlamps,No gas tube, flashlamps, laser rod, water coolinglaser rod, water cooling

PortablePortableNo special power

No cooling connectionNo heat

Quiet

AffordableAffordableMore powerful, less traumatic

250microsecond-10sec0.05 Hz - 200 Hz

Expand PracticeExpand Practice* Sulcular debridement* Root canal treatment

Caries RemovalCaries RemovalCavity PreparationCavity Preparation

Hard tissue modificationHard tissue modificationSoft tissue modificationSoft tissue modification

Peak absorption Peak absorption of water water and

HydroxyapatiteHydroxyapatite

Vaporize the water rapidlyVaporize the water rapidlyAcusto-mechanical waveAcusto-mechanical wave

What is orthodontics???

•Branch of dentistry concerned with prevention, interception and correction of malocclusion and other abnormalities of the dento facial region.

Here is why pateints come commonly to a orthodontist….

The result we achieve by our treatment….

Future Trends in Future Trends in DentistryDentistry

• No painNo pain• SmileSmile

WHY ORTHDONTIC TREATEMENT ???

No pain?

• Pain

• Vibration

• Sound

Smile?

• Esthetic needs

• Non invasive

Incision, Excison, Vaporization, Ablation, HemostasisDecontamination, Aphtous Ulcer Tx, Drain AbscessOpeculectomy, Surgical uncovering, Enamel exposure Root canal treatment

LASERS..WHY SHOULD I??

• PRECISION• POWER• PERFORMANCE

– TIME – ANTI CARIOGENIC – PREVENTS

DECALCIFICATION

Why Etching in orthodontics???

• The primary effect of enamel etching is to increase the surface area and thereby change the surface from a low energy hydrophobic surface to high-energy hydrophilic surface ( Reynolds, 1975 ).

• Various surface properties may be accomplished but the most important point is to modify the surface characteristic of the enamel for adhesive attachment ( Silverstone et al. , 1975 ).

• Various preparation methods including orthophosphoric acid, sandblasting, and laser irradiation have been shown to etch enamel for orthodontic bonding

• Acid etching decalcifies the inorganic component of the enamel and the enamel becomes more susceptible to carious attack, which is induced by plaque accumulation around the bonded orthodontic attachments.

• Laser irradiation removes the smear layer. After laser etching, some physical changes occur, such as melting and recrystallization.

Numerous pores and bubble-like inclusions appear Thus, irregular surfaces are created which permit penetration of fluid adhesive components.

The main disadvantage was the immediate increase in temperature, resulting in an inflammatory pulpal response

• The main advantage of the laser-etched surface is acid resistance. It yields more resistant enamel for caries attack

Reason ????

• The purpose of my thesis work is to investigate the shear – peel bond strength and adhesive failure location of laser- and sandblasted-etched enamel compared with conventional acid-etching techniques, and to determine the suitability of these modalities in bonding of brackets…

WHY DID I CHOOSE LASERS??

This is where I want to reach… Treatment should be available to every one irrespective what our economic status…

How do we do this

RESEARCH is the

key ….

What role do researchers play ???

• Well it’s the researchers contribution that today numerous dental procedures are affordable by the masses….

• Different studies carried out over the years have gifted dentistry with introduction of lasers…

Frenectomy

Gingival troughing

Minimal marginal gingival regeneration: A, placement of topical anesthetic on a previously impacted canine with short clinical crown height;B, gingivectomy performed with an Er,Cr:YSGG, Waterlase; strict hemostasis with an erbium laser may be difficult; C, gingivectomy complete and tissue tag removed (photo taken immediately postoperatively); D, 3-month postsurgical follow-up with minimal marginal gingival regeneration.

Application of low level of laser

Gingival Recontouring

Gingivoplasty

EXPLORE NEW VISTAS,

LET LASER TRANSFER

YOUR PRACTICE

KEEP SMILING….

THANK YOU…..