Dental News June 2019

Page 16

Laser Dentistry

Introduction To Laser Applications in Dental Treatments Laser History

Dr. Hoda El Hallal Dental Surgeon Private Practice in Beirut-Lebanon Diploma in Oral Biology DOB Fellowship & Master of Science MSc in Laser Dentistry Professor a.c. at Genoa University Reviewer at LIMS

In 1960, the American physicist Theodore Maiman created the first Laser1 at Hughes Research laboratory, Malibu - California. He was able to take a rod of ruby, a synthetic crystal, to energize it with a flashlamp & to produce red laser light in the visible spectrum at 694 nm, that he could see. In 1965, Ralph H. Stern and Reidar Sognnaes2, from the University of California - Los Ange-

les, used the ruby laser to vaporize enamel and dentin. Hard tissue ablation with ruby laser reported an increase in pulpal temperature with detrimental effects. Technology should wait until 1989, when the American dentist Terry Myers designed the first Nd:YAG laser specifically for dentistry. Since then, clinical applications continue to increase making laser use one of dentistry’s most exciting advances.

Different dental laser wavelengths (visible & infrared invisible range) & the electromagnetic spectrum (fig.1) Nowadays, available commercial dental lasers are in the range of 377nm to 10600nm and are all nonionizing electromagnetic radiation i.e. they do not cause any mutations in the cellular DNA3 components like gamma-rays and X-rays. Some are in the visible spectrum of light (about 380nm – 750nm) such as Alexandrite laser 377nm violet light that has a very high absorption in calculus and not so high absorption in dentin. Another laser in the visible spectrum is, the new blue diode laser 445nm, that is very highly absorbed in hemoglobin, almost 500 times as well as 810nm diode lasers permitting very easy soft tissue ablation. Argon laser, no longer available for dentistry, that has 2 wavelengths one 488nm is blue light for composite curing and the other is 514nm in the intense green light, helpful for soft tissue ablation. The frequency doubled Nd:YAG 532nm green color laser also called KTP (Potassium Titanyl Phosphate) laser very useful for photochemical bleaching. He-Ne (Helium Neon) laser has 632nm red light or Diagnodent caries diagnostic laser uses a visible red wavelength of 655nm etc. All the rest of the dental lasers emit invisible light in the near, mid and far infrared portion of the electromagnetic spectrum: The diode laser (805, 808, 810, 830, 940, 980 and 1064nm), the Nd:YAG laser (1064nm), the Erbium family lasers with the Er,Cr:YSGG laser (2780nm) and Er:YAG laser (2940nm), the CO2 laser (9300, 9600 & 10600nm)4.


Dental News

June 2019