A dental laser is a type of

laser A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The ...

designed specifically for use in oral surgery or dentistry. In the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

, the use of lasers on the

gums The gums or gingiva (plural: ''gingivae'') consist of the mucosal tissue that lies over the mandible and maxilla inside the mouth. Gum health and disease can have an effect on general health. Structure The gums are part of the soft tissue lin ...

was first approved by the

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...

in the early 1990s, and use on hard tissue like

teeth A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, t ...

or the bone of the

mandible In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone ...

gained approval in 1996. Several variants of dental lasers are in use with different

wavelength In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats. It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, t ...

s and these mean they are better suited for different applications.

Soft tissue lasers

* Diode lasers *

Carbon dioxide laser The carbon-dioxide laser (CO2 laser) was one of the earliest gas lasers to be developed. It was invented by Kumar Patel of Bell Labs in 1964 and is still one of the most useful types of laser. Carbon-dioxide lasers are the highest-power contin ...

s * Nd:YAG laser Diode lasers wavelengths in the 810–1,100 nm range are poorly absorbed by the soft tissues such as the

gingiva The gums or gingiva (plural: ''gingivae'') consist of the mucosal tissue that lies over the mandible and maxilla inside the mouth. Gum health and disease can have an effect on general health. Structure The gums are part of the soft tissue lin ...

e, and cannot be used for soft tissue cutting or ablation. Instead, the distal end of diode’s glass fiber is charred (by burned ink or by burned corkwood, etc.) and the char is heated by the 810-1,100 nm laser beam, which in turn heats up the glass fiber’ tip. The soft tissue is cut, on contact, by the hot charred glass tip and not by the laser beam itself. This is used for variety of oral surgery procedures such as

gingivectomy Gingivectomy is a dental procedure in which a dentist or oral surgeon cuts away part of the gums in the mouth (the '' gingiva''). It is the oldest surgical approach in periodontal therapy and is usually done for improvement of aesthetics or p ...

frenectomy A frenectomy is the removal of a frenulum, a small fold of tissue that prevents an organ in the body from moving too far. It can refer to frenula in several places on the human body. It is related to frenuloplasty, a surgical alteration in a f ...

, treatment of

Pericoronitis Pericoronitis is inflammation of the soft tissues surrounding the crown of a partially erupted tooth, including the gingiva (gums) and the dental follicle. The soft tissue covering a partially erupted tooth is known as an ''operculum'', an ar ...

, and exposure of superficially impacted teeth. This method was primarily used by the Michigan school of dentistry . Similarly Nd:YAG lasers are used for soft tissue surgeries in the

oral cavity In animal anatomy, the mouth, also known as the oral cavity, or in Latin cavum oris, is the opening through which many animals take in food and issue vocal sounds. It is also the cavity lying at the upper end of the alimentary canal, bounded on t ...

, such as

, periodontal sulcular debridement,

LANAP Laser-assisted new attachment procedure (LANAP) is a surgical therapy for the treatment of periodontitis, intended to work through regeneration rather than resection. This therapy and the laser used to perform it have been in use since 1994. It wa ...

biopsy A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a dise ...

, and

coagulation Coagulation, also known as clotting, is the process by which blood changes from a liquid to a gel, forming a blood clot. It potentially results in hemostasis, the cessation of blood loss from a damaged vessel, followed by repair. The mechanis ...

of graft donor sites. The Nd:YAG laser wavelength are partially absorbed by pigment in the tissue such as hemoglobin and melanin. These lasers are often used for

debridement Debridement is the medical removal of dead, damaged, or infected tissue to improve the healing potential of the remaining healthy tissue. Removal may be surgical, mechanical, chemical, autolytic (self-digestion), and by maggot therapy. In p ...

and disinfection of

periodontal Periodontology or periodontics (from Ancient Greek , – 'around'; and , – 'tooth', genitive , ) is the specialty of dentistry that studies supporting structures of teeth, as well as diseases and conditions that affect them. The supporting ...

pockets. Their coagulative ability to form fibrin allows them to seal treated pockets. The CO₂ laser remains the best surgical laser for the soft tissue where both cutting and

hemostasis In biology, hemostasis or haemostasis is a process to prevent and stop bleeding, meaning to keep blood within a damaged blood vessel (the opposite of hemostasis is hemorrhage). It is the first stage of wound healing. This involves coagulation, ...

is achieved photo-thermally (radiantly).

Soft and hard tissue lasers

* Er:YAG laser *

* Er,Cr:YSGG laser Erbium lasers are both hard and soft tissue capable. They can be used for a host of dental procedures, and allow for more procedures to be done without local anaesthesia. Erbium lasers can be used for hard tissue procedures like bone cutting and create minimal thermal and mechanical trauma to adjacent tissues. These hard tissue procedures show an excellent healing response. Soft tissue applications with erbium lasers feature less hemostasis and coagulation abilities relative to the CO₂ lasers. Er,Cr:YSGG laser was found to be effective in gum de-pigmentation. The new CO₂ laser operating at 9,300 nm features strong absorption in both soft and hard tissue and is the newest alternative to erbium lasers. The 9,300 nm laser ablates hard tissue in excess of 5,000 °C, which often results in extremely bright thermal radiation.

Dental caries removal

In September 2016 the Cochrane collaboration published a systematic review of the current evidence comparing the use of lasers for

caries Tooth decay, also known as cavities or caries, is the breakdown of teeth due to acids produced by bacteria. The cavities may be a number of different colors from yellow to black. Symptoms may include pain and difficulty with eating. Complicatio ...

removal, in both

deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, ...

and adult teeth, with the standard dental drill. Nine trials were reviewed, published between 1998 and 2014, with 662 participants in total. These included three different types of laser: Er:YAG; Er,Cr:YSGG; and Nd:YAG. Overall the quality of evidence available was found to be low, and the authors were unable to recommend one method of caries removal over the other. There was no evidence of a difference between the marginal integrity or durability of the restorations placed. However, there was some evidence that the laser-produced less pain and required less anaesthesia than the drill. The authors concluded that more research is required.

Cost of lasers

Use of the dental laser remains limited, with cost and effectiveness being the primary barriers. The cost of a dental laser ranges from $4,000 to $130,000, where a pneumatic

dental drill A dental drill or handpiece is a hand-held, mechanical instrument used to perform a variety of common dental procedures, including removing decay, polishing fillings, performing cosmetic dentistry, and altering prostheses. The handpiece itse ...

costs between $200 and $500. Hard tissue lasers are incapable of performing some routine operations in the treatment of cavities.

Benefits of lasers

Dental lasers are not without their benefits, though, as the use of a laser can decrease

morbidity A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...

after surgery, and reduces the need for

anesthetics An anesthetic (American English) or anaesthetic (British English; see spelling differences) is a drug used to induce anesthesia ⁠— ⁠in other words, to result in a temporary loss of sensation or awareness. They may be divided into two ...

. Because of the cauterisation of tissue there will be little bleeding following soft tissue procedures, and some of the risks of alternative

electrosurgery Electrosurgery is the application of a high-frequency (radio frequency) alternating polarity, electrical current to biological tissue as a means to cut, coagulate, desiccate, or fulgurate tissue.Hainer BL, "Fundamentals of electrosurgery", ''J ...

procedures are avoided. Additionally, the use of dental lasers is associated with less vibration and a more favorable noise profile when compared to pneumatic dental drills.

History

Kumar Patel Chandra Kumar Naranbhai Patel (born 2 July 1938) is an electrical engineer. He developed the carbon dioxide laser in 1963; it is now widely used in industry for cutting and engraving a wide range of materials like plastic and wood. Because th ...

made the first CO₂ laser in 1964, in the same year the Nd:YAG Laser was invented at

Bell Labs Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984), then AT&T Bell Laboratories (1984–1996) and Bell Labs Innovations (1996–2007), is an American industrial Research and development, research and scientific developm ...

.{{Cite web , url=http://www.kigre.com/files/historylasers.pdf , title=A brief history of lasers , access-date=2014-06-16 , archive-url=https://web.archive.org/web/20140611181322/http://www.kigre.com/files/historylasers.pdf , archive-date=2014-06-11 , url-status=dead

References

Dental equipment