IDRR APRIL -MAY -JUNE 2020 - Flipbook - Page 32
LASER DENTISTRY
Fig.3.
Theodore Maiman with his rst ruby laser
an optical resonator which could create a coherent
beam of light (A beam of light in which all the photons
are spatio-temporally “in-phase” or sync with each
other)
On May 16, 1960, Theodore H. ‘Ted’ Maiman at
Hughes Research Laboratories demonstrated the first
working prototype of the laser device. A pure Ruby
crystal was used as an active media and the device
which was credited as the first laser had a wavelength
of 694.3 nm i.e. it emitted a deep red beam of light.
This device used a solid medium of aluminum oxide
(i.e., sapphire) containing chromium ions to produce
a visible red radiation. Though it could only be used in
the pulsed mode, it delivered a collimated, coherent
and monochromatic source of light similar to the
modern lasers that we have today. In the same year,
the first gas laser was also made.4,5
In 1963, CO2 laser was developed by the legendary
Kumar Patel. It was having better efficiency than the
ruby lasers. Later with time many other lasers were
introduced some of which contained semiconductors,
neodymium-doped yttrium aluminium garnets, argon
ions, chemical lasers, metal vapor lasers etc. 6
Since there is a specific correlation between the
July-August-September 2019
wavelength and absorption of light by an irradiated
target, pioneers like Dr. Leon Goldman began their
research on laser tissue interaction in human subjects.
The experiments on rats had already showed that light
could be used for healing and rejuvenation purposes.7
History shows that the first stimulated emission was
associated with microwaves, now with UV and
Infrared range and the work is in progress with other
wavelengths as well. As per the laws of photonics,
laser light is very pure and special because it can
propagate in the same phase without divergence,
have narrow bandwidth and can be emitted
continuously, or alternatively in short or ultrashort
pulses with a varied duration of microsecond to
femtoseconds. As a result of these developments,
Lasers which were used initially for medical purposes
are also used in dentistry now, after almost a gap of 3
decades! 8,9,10
CONTEMPORARY APPLICATIONS OF LASERS.
There are many applications of lasers such as laser
range finding, laser surgery, laser spectroscopy,
cutting engraving etc. But what has recently caught
everybody’s attention is Laser PBMT (Photo bio modulation therapy) or LLLT. 11,12
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