SEMINAR ON LASERS

DEPT OF ORAL AND MAXILLOFACIAL SURGERY

Presented By : Sahal Abu IV th year BDS Part A

LASERS AND IT’Z USES IN DENTISTRY

• Introduction• History• Fundamentals Of Laser Operation• Classification Of Lasers• Current Uses• Technique For Use Of Laser In OMFS• Laser Safety • Conclusion

Introduction

• Advances in technology are increasing and changing the ways that patient experience dental treatment. Technology helps to reduce treatment time and treatment more comfortable.

• One of the milestones in technological advancements in dentistry is the use of LASERS.

• The term Laser is the acronym for “Light Amplification by Stimulated Emission of Radiation”.

• They provide more efficient , more comfortable and more predictable outcomes for the patient.

HISTORY

1917- Einsteen Theory of stimulated emission

1958 – Townes & Schawlow Laser principle

1960 - Maiman Ruby laser

1961 - Johnson Neodymium ion doped yttrium aluminium garnet rod

1964 - Patel CO2 Laser

1977 - Shafir First documented case in OMFS using lasers

1989 – Terr Myers First Dental Laser – Nd:YAG

Fundamentals Of Laser Operation

• Components - Active medium [ Lasing Medium ]

Pumping mechanism Optical Resonators

Laser Delivery System Cooling system Control Panel

Properties Of LASER

Monochromaticity Directionality Coherence Brightness

Photobiology Of Lasers

• Photochemical Biostimulation - Stimulatory effects of laser

on biochemical and molecular processes that normally occur in tissues such as healing and repair.

Photodynamic Therapy – induce reactions in tissues for the treatment of pathologic condition.

Tissue fluorescence - used as a diagnostic method to detect light reactive substance in tissue.

• Photo thermal interactions- Photo ablation – removal of tissue by

vaporization and super heating of tissue fluids , coagulation, and hemostasis.

Photopyrolysis

• Photomechanical Photo disruption - breaking apart of

structures by laser light. Photoaccoustic interaction- involve

removal of tissue with shock wave generation.

• Photoelectrical Interaction- include photoplasmolysis which describes how tissue is removed through the formation of electrically charged ions and particles that exist in a semi gaseous high energy state.

LASER INTERACTION WITH ORAL BIOLOGIC TISSUE

• Photocoagulation : Laser heats the tissues to 60 deg C for a limited time leading to coagulation of the tissues with minimal alteration in the appearance of tissue structure. As a result of these proteins enzymes cytokines and other bio active molecules get denatured.

Classification Of Lasers

General Classification

Class 1 Non Hazardous Producing Laser

Class 2 Hazard producing when passed through magnifying optics

Class 2 M Safe, if not viewed through optical instruments

Class 3 R Safe with restricted beam viewing

Class 3 B Direct viewing hazardous to eye

Class 4 Serious injury potential to eye and skin

Laser Classification as per medium Used

Solid State Laser Eg-Neodymium-yttrium aluminium garnet laser

Gas Laser Eg- Helium & Helium Neon

Excimer Laser Uses reactive gases like chlorine and fluorine eg : argon laser

Dye Laser Complex dyes like Rhodamine 6G

Medical Classification Of Lasers

High Power Lasers- Used for surgical purpose

Low power Lasers- Used to promote tissue regeneration

General Medical Uses Of Laser

• Angioplasty• Cancer diagnosis• Cancer treatment• Laser hair removal , tattoo removal• Dermatology• Medical imaging• Microscopy• Ophthalmology• Optical coherence tomography• Prostatectomy• Surgery

Photodynamic Therapy

Uses In Dentistry

Excimer Lasers

• Hard tissue ablation/ Dental Caries removal. Argon Fluoride / Xenon fluoride lasers are used. They have a wave length from193nm to 308nm.

Gas Laser

• Carbon dioxide lasers are used for intra oral and implant soft tissue surgery , aphthous ulcer , melanin pigmentation. Has a wavelength of 10600nm. Color- Infrared

• Helium Neon Lasers has a wavelength of 637nm and is used for dentin hypersensitivity , analgesia etc. Color-Red

• Argon lasers having a wavelength of 488nm & are used for tooth whitening , curing of composites , curettage etc Color-Blue

Diode Lasers

• Indium Gallium Arsenide Phosphorous are used for caries and calculus detection and has wavelength of 655nm. The color of the laser is Red.

• Gallium Aluminum Laser – Intra oral Surgery , Implant soft tissue surgery , sulcular debridement , Pulpotomy , root canal disinfection removal of enamel caries etc, Wavelength- 840nm Color-Infrared

Solid state Laser

• Neodymium:YAG Laser – Intra oral soft tissue surgery , sulcular debridement , analgesia , Pulpotomy , root canal treatment, removal of gingival melanin pigmentation . Has a wave length of 1064nm and is infrared.

Erbium Group

• Erbium:YAG is used for modification of enamel and dentin surface , implant soft tissue surgery , sulcular debridement , osseous surgery , treatment of dentin hypersensitivity , apthous ulcer treatment etc

Techniques For Incisional Biopsy

• Provide local or general anesthesia.• Outline the intended superficial incision line without deep

penetration.• Connect the outline marks.• Excise the specimen.• Obtain Homeostasis.• Consider the need for suturing.• Consider tagging the biopsy margins.

Lesions treated

• Fibroma• Mucocele• Papilloma• Gingival lesion• Salivary stones• Malignancy removal• Vestibuloplasty• Incisional and excisional biopsy• Tongue lesion treatment

Technique for ablation and vaporization

• Laser vaporization is an effective , non-morbid , inexpensive , quick , and relatively painless method of managing pre malignant lesions.

• A spot size of 1.5 to 3mm is typical for most intra oral vaporization procedures. The beam is transverse in vertical strokes.

• A constant speed must be maintained to create a uniform depth. Increasing depth can be accomplished by increasing power.

• Allows for removal of a surface lesion in layers.

Uses Of Laser Ablation

• Solar chelitis• Leukoplakia• Dysplasia• Lichen Planus• Oral melanosis• Nicotine stomatitis• Tissue hyperplasia

• Lasers are also used in arthroscopic surgery of TMJ

• Scar revision is also made possible these days with the help of pulsed dye lasers[PDL]. PDL have hb as their chromophores and penetrate the epidermis without de-epithelisation. They reduce scar tissue erythema and induce collagen remodeling to flatten and soften scars. Indicated in cases with erythematous and hypertrophic scars of maxillofacial region.

Low level Laser therapy

• Also known as therapeutic laser treatment.• Promotes tissue healing , reduces edema ,

inflammation and pain.• Used in cases of – dermatological conditions , neural

ailments , mucoskeletal ailments etc

• Easy and safe to handle• Improved surgical versality- ability to vaporize coagulate

and incise tissue.• Reduces / Eliminate bleeding.• Spot coagulation and vaporization gives excellent

hemostasis.• Reduces Operating Time.• Anesthesia free soft and hard tissue cutting• No need for suturing• Instant sterilization of surgical site• No sensory disturbances• No functional /mobility disorder

Demerits

• Cannot be used in teeth with restoration and prosthesis.

• Hazard to patient , operating and assisting team.• Maintenance requirements • Electrical hazards of laser equipments• Expense of laser equipments• Specialized arrangements• Fire hazards

Laser Hazards

• Primary Hazards: Caused directly by laser beam. Endangers mainly two organs- Eyes and Skin In case of eyes it damages retina , cornea , & the lens and

slight carelessness can destroy vision permanently.

• Secondary Hazards : Its related to operation of the laser and are independent of radiation characteristics.

Operating Room Safety

• Use of non inflammable materials• Use of eye shields for the patient• Use of laser resistant shielding materials for

surgical field and for protecting anesthesia equipments

• Certain anesthesia techniques may also decrease potential hazard

Patient Safety

Personnel Safety

• Post signs that lasers are being used• Eye shields to be worn by all personnel in operating

room• Safety shields must be used• A laser safety officer should be stationed at the laser

unit• Use only wet cloth in operative field• Use only non-combustible anesthetic agent• Avoid alcohol based topical anesthetic and gauze• Protect tissues adjacent to surgical site

Sterilization And Infection Control Of Laser Unit

• Steam sterilization is the standard of care• Protective housing around the laser and

articulating arm should receive spray disinfectant

Conclusion

• The past decade has seen a variable explosion of research into clinical application of lasers in dental practice. Laser treatment not only is helpful in treating general problems of the teeth but also helps to reduce the fear and anxiety of the patient towards the treatment.