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LASER
is an acronym:
L
light
A amplification
(by)
S stimulated
E emission (of)
R radiation
Laser consist of
an active medium and a pumping source enclosed in an optical
cavity. The active source
pumps the active medium (the laser medium itself) from its
ground state (zero, inactive state) to an exited
state. “Population inversion” occurs when the
two sources are mixed together and photons are given
off thereby producing the “Laser” activity. This
activity is resonated or reflected back and forth within an
optical resonator and amplified. A portion of this activity
is then emitted as a LASER beam. Beam splitters
or mirrors are used to capture the particular portion of the
LASER beam that is needed to perform surgical
operation.
The
main properties of the beam are:
- Narrow wavelength
- very little divergence
of the beam as it travels away from the source. This allows
the beam to be
focused to very small spots (unlike a conventional light bulb
that emits the beam in many directions)
- All of the photons
that have been given off when the population inversion occurred
are “in phase” both
in space and time. The active medium of a laser can be either
gas, solid or liquid.
LASER
TYPES-LASER PROPERTIES
DIODE
LASER
The active medium
of the diode laser is a semi-conductor P-N junction made in
a GaAIA s crystal. A
flexible fibre is used to transmit the laser energy to the
surgical site. It works best on soft tissues and can
cut very precisely with little or no collateral depending
on the settings used during the surgery.
The DIODE laser
many times can be used without anaesthesia doing very precise
anterior aesthetic
surgery without causing bleeding or discomfort. It is the
best laser for that purpose. DIODE is also used for
tooth whitening.
CO2
LASER
The active medium
is gaseous CO2 a proprietary hollow wave length technology
is used to deliver the
LASER energy to the surgical site. The wave guides are coated
to form an internal reflection that allows the
flexible wave guide to be used for the delivery of the LASER
energy to surgical site. It is highly absorbed in
water and is very good at cutting soft tissue without causing
bleeding depending on the settings used with
the LASER. It is also the best laser to use to control bleeding
in an area.
ERBIUM
LASER
The active medium
of the Erbium laser is the solid medium of Erbium. The Erbium
laser is used in a
pulsed mode and is highly absorbed in water in very low depths.
When used on hard tissues the Erbium
laser energy that touches the hard tissue heats up the water
within the hard tissue and causes that water
to be turned into steam. That causes a mini explosion to occur
and the hard tissue is ablated (removed).
The tissue below
is not affected in the least since the laser only works in
a very low depths, thereby
allowing precise control. This allows us to cut hard tissue
or bone many times without anaesthesia and be
infinitely more precise than we could with any drill we have
ever used in the past.
The Erbium laser
can also be used to cut soft tissue but it is not as precise
as DIODE laser and it does not
control bleeding. There are times when this is exactly what’s
needed and that is when you use the Erbium
LASER to cut soft tissue. When we are working with a hard
tissue like silver fillings, crowns or porcelain
that do not have any water inside then we cannot cut with
laser. We therefore need to use a burr to remove
the material.
The fact that the
Erbium laser does not affect certain materials like silver
fillings, enables us to perform
work close or next to a porcelain crown or bridge without
the risk of damage to the existing restorations.
The Erbium laser does work well if we have to remove composite
(white plastic) fillings however.
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