Apidays Singapore 2024 - Modernizing Securities Finance by Madhu Subbu
Medical problem 3 4
1. Islam Kassem, BDS , MSc, MOMS RCPS Glasg,
FFD RCSI
Consultant Oral & Maxillofacial Surgeon
Medical Topics in
Orthodontics
ikassem@dr.com
2. Criteria of selected technique
Effect on healing
Effect on pain
Effect on edema
Effect on intra operative bleeding
Effect on Tooth structure
ikassem@dr.com
3. L A S E R
Light Amplification
by
Stimulate
d
Emission
of
Radiation
Lasers
Laser theory
ikassem@dr.com
4. Model of an atom by Niels Bohr
Born in Copenhagen
1922: Nobel Physics Prize
winner
Lasers
Laser theory - basics
ikassem@dr.com
5. The laser – a very special light
ikassem@dr.com
7. Coherence:
Temporal and spatial
synchronization of wave
movement
Lasers
Laser theory – Basics: laser light
Normal light Laser light (coherent)
Temporal
coherenc
e
Spatial
coherenc
e
Laser
ikassem@dr.com
8. Lasers
Design of a laser
Fully reflecting
mirror
Resonator
Reflector
Semipermeable mirror
Reflector
Medium
Flash lamp
Laser medium
ikassem@dr.com
14. Warm-up
37 – 60°C
none
none
Penetration
of protein
60 – 65°C
Whitish-gray
coloration,
increased
dispersion
Decomposition
Desiccation
90 – 100°C
Constant
dispersion
Shrinkage,
dehydration
Carbonization
Several hundred °C
Black
coloration,
increased
absorption
Strong
mechanical
damage
Vaporization
Combustion
Formation
of smoke
and gas
Ablation
Temperature
Process
Optical
change
Mechanical
change
Lasers
Interactions between laser light and tissue
ikassem@dr.com
15. Lasers
Effect of the laser on biological tissue
Damage
reversible irreversible
Vaporization
Carbonization
Coagulation
Laser beam
Tissue
Hyperemia
ikassem@dr.com
17. Effects on human tissue
Transmission
Absorption
Reflection
Lasers
Laser-tissue interaction: Beam trajectory
Dispersion
ikassem@dr.com
18. A therapeutic effect is attained
only if the tissue absorbs the laser energy!
Lasers
Laser-tissue interaction
ikassem@dr.com
19. Chromophores
According to the optical properties of
tissues. For example CO2 Water
This Character is strongly affected by the
laser physical properties .
ikassem@dr.com
20. Carbon dioxide laser
Patel et al., working in Bell laboratories in 1964,
were the first to develop the CO2 laser.
Carbon dioxide (CO2 ) lasers have been used in
dentistry in the specialty practice of oral surgery
and periodontology since the early 1980s, in the
past five years, the use of these lasers has
extended into general practice.
CO2 laser was the first laser approved by the FDA
ikassem@dr.com
21. Of greatest significance is the high degree of
absorption by oral mucosal tissues, which are
composed of 90% water. Absorption of the laser
by intracellular water results in a photo thermal
effect that is manifested by cellular rupture.
This cellular vaporization is the basis for the use of
the CO2 laser as a surgical tool.
Heat is generated and conducted into surrounding
tissues, creating a zone of lateral thermal damage;
this zone of necrosis has been found to be 500
mm or less Lateral thermal damage results in
coagulation of vessels up to 500 mm in diameter
and is clinically manifested by homeostasis.
ikassem@dr.com
22. Post surgical bacteremia also has been found
to be greatly reduced with laser use as a
result of sealing of blood vessels and
lymphatic compared with other methods of
incision Laser wounds exhibit histological
features that confer significant advantages
over those created by scalpel .
ikassem@dr.com
24. Laser Hazards
Class I
Laser videodisk
Class II
Laser Pointer
Class III
Surgical laser
Class IV
Fire laser
ikassem@dr.com
25. Laser Safety & Protection
1- Eye protection
2- protection to lips , skin of the face
3- Protection from fire , toxic gases .
4- Laser reflection from surgical instrument.
5-Hazards of laser smokes
ikassem@dr.com