Lasers in Orthodontics: A Brief History and Applications

Lasers in Orthodontics

www.indiandentalacademy.com

INDIAN DENTAL ACADEMY
Leader in continuing dental education


• Introduction
• History of lasers
• Uses of lasers in orthodontics
1. Laser scanning
2. Holography
3. Soft tissue uses
4. Hard tissue uses
5. Laser welders
• Conclusion
• References

Introduction
Lasers were developed in the early 1960's and
rapidly found a number of uses in medicine and
surgery. Although only recently introduced into
general dentistry, they have been used in orthodontics
for a number of years. This seminar gives a brief
summary of some of the current applications &
ongoing research for lasers in orthodontics.


• The term laser is an acronym for Light Amplification
by the Stimulated Emission of Radiation. Laser
energy is produced when a suitable medium, for
example a ruby crystal, is subjected to certain physical
constraints at high energy. The medium is stimulated
by an external power source to produce photons of
light energy which are then amplified to produce laser
emission.


• The mediums are molecules in solid, liquid, or gas
state. Gas lasers such as CO2 or helium-neon, use an
electrical discharge to produce the emissions whereas
doped-insulator lasers (ruby or Nd:Y AG) employ
flash lights as the energy source.


• The photons are made to pass back and forth through
the laser medium by parallel facing mirrors gathering
more photons of energy which are thus amplified by
this process. One of the mirrors is semi silvered and
allows a proportion of the energy to escape and form
the laser beam. The laser radiation has the unique
properties of being coherent, mono-chromatic and
columnated; that is, it has the same amplitude, phase
and wavelength.


• It is these properties that distinguish laser radiation
from types of radiation or light sources and allows a
considerable amount of energy to be focused onto an
extremely small area. The effect that the laser beam
has on various tissues depends on the nature of the
tissue itself, the energy level (power) and wavelength
of the beam. The wavelength of the beam is altered
principally by changing the laser medium.


EARLY DENTAL LASER RESEARCH
• The first laser constructed by Maiman was a pulsed
ruby laser, which emitted light of 0.694 µm
wavelength (Maiman, 1960). Surprisingly, the second
laser to be developed was the neodymium laser, which
followed only one year later (Snitzer, 1961). Nearly
all of the early dental laser research was performed
with the ruby laser, which may have resulted in a
delay in the development of laser dentistry. Had
dental researchers focused on the neodymium laser
sooner, laser dentistry may have progressed to its
present status some 10 years earlier.

The Ruby Laser
• Dental laser research began in 1963 at the University
of California at Los Angeles School of Dentistry with
the investigations of Ralph H. Stern and Reidar F.
Sognnaes. Like most of the early dental laser
researchers, interests centered around the thermal
effects of the ruby laser on the dental hard tissues
(enamel and dentin) and restorative materials.


• They reported the development of cratering and
glasslike fusion of enamel, and the penetration and
charring of dentin following a single millisecond pulse
of the ruby laser at 500 to 2,000 J/cm2 (Stern, 1964).
• In further experiments they observed that under
specific parameters of exposure to the ruby laser there
occurred an increased resistance to acid penetration
into enamel, suggesting a possible role for the laser in
caries prevention (Stern, 1974).


• The first report of laser exposure to a vital human
tooth appeared in 1965 when Leon Goldman, MD,
applied two pulses of a ruby laser to the tooth of his
brother, Bernard, who was a dentist. According to
their report (Goldman et al, 1965), the first dental
laser patient experienced no pain with only
superficial damage to the crown. Ironically, the first
laser dentist was a physician and the first dental laser
patient was a dentist.


• Unfortunately, the results of other early dental
research with the ruby laser were not as promising.
Most experiments involving the application of this
laser to teeth produced unfavorable results, which
may be attributed to the destructive interaction of the
6.943-nm wavelength with dental hard tissue..


The Carbon Dioxide Laser
• From the 1960s to the early 1980s, dental researchers
continued to search for other types of lasers that
might be more effective for application to hard tissue.
In the United States, Stern at UCLA and Lobene at
the Forsyth Dental Center in Boston shifted their
attention to the carbon dioxide laser.


• Because its wavelength of 10.6 µm is well absorbed
by enamel, it was thought that the carbon dioxide
laser might be suitable for selected surface
applications to teeth, such as the sealing of pits and
fissures; the welding of ceramic materials to enamel;
or the prevention of dental caries (Lobene and Fine,
1966; Lobene et al, 1968; Stern et al, 1972).


The Neodymium Laser
• The first report of dental application of the
neodymium laser to vital oral tissue in experimental
animals was that of Yamamoto and others from
Tohoku University School of Dentistry in Japan
(Yamamoto and Ooya, 1974). In a series of
experiments, Yamamoto determined that the Nd:YAG
laser was an effective tool for inhibiting the
formation of incipient caries both in vitro and in vivo
(Yamamoto et al, 1974; Yamamoto and Sato, 1980).

• During this same time, Adrian, who was working at
the U.S. Army Institute of Dental Research at
Walter Reed Medical Center, began to consider the
neodymium laser for use on teeth and for laser
welding of dental alloys (Adrian, 1977; Adrian and
Huget. 1977).


• Regulations cover the use of lasers and they are
classified from I (safe) to IV (use with care). Type III
and IV lasers have the strictest control and must be
used in designated areas, where suitable safety
precautions to prevent accidental injuries to staff and
patients have to be complied with. In general, hard
lasers will cut through tissue whereas 'soft' lasers will
not.
• The main applications for lasers in orthodontics are
for laser scanning, holography, soft tissue and hard
tissue uses.

Laser Scanning
• This is a method of three dimensional image capture
which has been described by Arridge et al, (1985) and
further developed by Moss et al, (1988).
• A low power, Helium-Neon, type II laser is fanned
across the subject's face or body and the reflected
beam is captured by a video camera.
• The information is then analyzed by specially
developed software and stored cn a computer. The
image can then be viewed on a computer screen and
rotated in any direction so that -all the individual
features can be viewed.

• Super imposition of serial scans is now possible and
therefore, longitudinal assessment of facial growth or
the results of facial surgery can be assessed. Further
developments of this technology may allow
superimposition of laser scan on a hard tissue CT
scan, thus producing a composite model of the
patient's soft and hard tissue.
• This technology awaits further development, but has
many exciting prospects, particularly in the areas of
facial growth study and the outcome of facial
surgery.

Shortcomings of3D laser scanning
• the slowness of the method, making distortion of the
scanned image likely;
• safety issues related to exposing the eyes to the laser
beam, especially in growing children;
• inability to capture the soft tissue surface texture,
which results in difficulties in identification of
landmarks that are dependent on surface color. Even
with the new white-light laser approaches that
capture surface texture color, the shortcomings persist

Holography
• Holographs can be used for three dimensional record
collection and stress analysis in hard tissues subjected
to various loading forces.
• Although holograms have been used for three
dimensional facial image recording, their main
application in terms of record collection is as a
substitute for orthodontic study casts (Keating et
al.,84).

• Harradine et al., (1990) carried out a study to assess
the feasibility of this technique. Although study
models have the advantage of being both accurate and
cheap, they suffer from the disadvantage of being
bulky and fragile.
• It has been estimated by the Dental Practice Board
that 50% of plaster models that are received by post
are broken on arrival. They are also bulky and
expensive to transport and store.

• Study models constitute part of a patient's record and
may need to be retained for some time after the
completion of orthodontic treatment.
• This problem has been highlighted in a joint statement
from the Medical Defence Union and Dental
Protection ,society (1994), which states: 'as a rule of
thumb, it is clear that the minimal possible time that
records should be kept would be eleven years, or seven
years after the age of majority (twenty-five years)
which ever is the longer'.

• Holograms are about the same size as radiographs or
photographs and are very resistant to damage. A
special camera is required which will take white laser
light reflection holograms from study casts (Holocam
System 70 camera, Holofax Limited, Rotherwas,
Hereford). Although holograms do produce a three
dimensional image, it is not possible to see all aspects
of the occlusion from one single picture.


• For each set of study casts, four views as a minimum
are needed; an occlusal view and three views in
occlusion-left buccal, right buccal and frontal. These
must be viewed with a special light box (Holo-fax
viewer, Holofax Limited) which allows viewing and
measurement of the hologram.
• However, there were some problems, principally
relating to a lack of familiarity with the hologram
and the fact that some views of the teeth were poor,
particularly in assessing overbite and actually
measuring the overjet.

Soft tissue applications
• CO2 lasers have been used in oral techniques for
operating on both hard and soft tissue (Shoji et ai.,
1985). This laser has the major drawback that due to
the wave length of the emitted light (10.6 microns),
the guiding system has to consist of a number of
jointed arms with mirrors to reflect the beam into a
large hand-held type of 'gun' delivery unit. This makes
this type of unit extremely unyielding and because
this wavelength is largely absorbed by water
molecules, it will www.indiandentalacademy.com both hard and soft
cut many tissues,
and has to be used with caution.

• The recently introduced Nd:Y AG (Neodymium:
Yttrium Aluminium-Garnet) laser, has a wave-length
of 1.06 microns and can be transmitted via a fiberoptic cable to handpieces which resemble conventional
dental instruments in size and shape.
• Using this laser in a pulsed mode, with each pulse
lasting only 30 picoseconds it is possible to cut soft
tissues relatively painlessly. This means that soft
tissue surgery can be performed without the need for
local anaesthetic, which may be useful for removing
opercula from partly erupted teeth.

• It is important to realize that this type of laser
cannot be used on bone because it will destroy bone
cells at a considerable depth, producing necrosis.
Therefore, it is not suitable for raising mucoperiosteal
flaps, or for performing extensive fraenectomies.
However, it can be used for simple exposures of teeth
where no flap is raised.


• The use of soft, non-cutting lasers has been suggested
for various dental applications including the
desensitization of hypersensitive dentine, to aid the
healing of dry sockets, promote healing and reduce the
discomfort associated with aphthous ulcers. However,
much of the evidence relating to this is anecdotal and
has never been proven by any properly conducted
scientific study.


Rossman and Cobb summarized the advantages of
lasers in soft tissue surgery:
(1) the laser cut is more precise than that of a scalpel,
(2) the cut is more visible initially because the laser seals
off blood vessels and lymphatics, leaving a clear dry
field,
(3) the laser sterilizes as it cuts, reducing the risk of
blood-borne transmission of disease,
(4) minimal postoperative pain and swelling have been
reported,
(5) less postoperative infection has been reported because
the wound is sealed with a biological dressing,

(6) less wound contraction occurs during mucosal healing,
thus scars do not
develop, and
(7) less damage occurs to adjacent tissues.
These qualities result in a shorter operative time and
faster postoperative recuperation.


• Three types of lasers are available for use in dentistry: the
CO2 laser, the erbium laser, and the diode laser. (Sarver &
Yanosky 2005)
• The CO2 laser can be somewhat difficult to use in practice.
It does not contact the tissue during the cutting phase; thus
there is no tactile feedback during the surgical incision. It
operates with a wavelength that is invisible to the eye, so
the fiber optic delivery system has a helium-neon (He-Ne)
laser with a wavelength of 632 nm incorporated as an
aiming beam. There is slight delay between when the
incision is made and when it can be seen.

• The erbium laser has a wavelength of 2790 to 2940
nm, which makes it ideal for absorption by both
hydroxyapatite and water. It can also be used to cut
soft tissue, but it does not control bleeding.
• The diode laser has a wavelength of 812 to 980 nm,
which is in the same range of the absorption
coefficient of melanin. The laser energy is absorbed by
pigmentation in the soft tissues, and this makes the
diode laser an excellent hemostatic agent. Because it
is used in contact mode, it also provides tactile
feedback during the surgical procedure. The diode
laser can often be used without anesthesia to perform
very precise anterior soft tissue esthetic surgery or
surgery in other areas of the mouth without bleeding
or discomfort.

Diode laser. A, Small size lends itself to
placement on mobile cart; B, instrument
is pencil-sized, making it convenient for
intraoral use.


• Soft tissue reacts differently to a diode laser than to a
scalpel. The laser can deliver energy in either a
continuous or a pulsed mode. In the continuous mode,
the tissues tend to absorb more energy, resulting in
greater heat. The pulsed mode permits intermittent
cooling between pulses of energy. Because the amount
of heat generated during the procedure translates
directly into the amount of collateral damage—and
thus postoperative discomfort—it is generally
recommended that the laser be used at a lower setting
and in the pulse mode for soft tissue procedures.

Hard tissue applications
• Current interest in the use of lasers in clinical
dentistry has suggested that this technology may be
applicable to the pretreatment of enamel for the
bonding of orthodontic adhesives, in a similar fashion
to acid etching. White et at., (1991) in an ex vivo
study found that Nd:Y AG pretreatment of enamel
improved composite bond strength to metal
orthodontic brackets.


• Roberts-Harry, (1992) compared acid etching and
laser pre-treatment of enamel prior to the clinical
placement of orthodontic brackets. The laser used in
this study was considerably slower, produced slightly
more discomfort and was substantially less reliable
than acid-etching. The laser was in fact, twenty times
slower than conventional acid-etching and gave a
bracket failure rate of 20.3% compared to nil bracket
failures with acid etching.


Appliance and
Adhesive

OrtholuxTM XT
Curing Light (3M
Unitek)

Metal Brackets
(APCTM Adhesive or
TransbondTM XT
Adhesive)

10 seconds mesial + 4 seconds mesial +
10 seconds distal
4 seconds distal

2 seconds mesial +
2 seconds distal

Ceramic Brackets
(APCTM Adhesive or
TransbondTM XT
Adhesive)

10 seconds through
the bracket

2 seconds through
the bracket

AccuCure 250 mW
(LaserMed)

4 seconds through
the bracket

Apollo 95E (DMD)

Molar Bonds (APCTM
Adhesive or
20 seconds mesial + 10 seconds mesial + 4 seconds mesial +
TransbondTM XT
20 seconds occlusal 10 seconds occlusal 4 seconds occlusal
Adhesive)
Molar Bands
(TransbondTM Plus
Light Cure Band
Adhesive)

30 seconds

15 seconds

6 seconds

Molar Bands
(UnitekTM Muti Cure
G.I. Band Cement)

40 seconds

20 seconds

8 seconds


• A Obata et al (1999) used super pulse CO2 laser for
bracket bonding and debonding.
• Both super pulse & normal pulse CO2 laser etching
resulted in a lower shear bond strength than that of
chemical etching.


Debonding ceramic brackets using
lasers
• The removal of ceramic orthodontic brackets can
present problems, including bracket wing failure,
enamel fracture, & toothache.
• The mechanism of conventional laser debonding is
based on the thermal softening of adhesive resin. This
occurs by heating the brackets with laser irradiation
to decrease the bond strength.

• This debonding mechanism however posses several
problems :1. Different adhesive resins require different
softening temperatures. Rueggeberg & Lockwood
reported that the temperature to soften adhesive
resins & thus weaken their bonding strengths
depend on the type of adhesive & ranges from
44º C to 228º C. Because of the potential thermal
pulpal damage during laser application, the
method & duration of laser pulse must be
precisely controlled & appropriate to the
adhesive resin.

2. The temperature of the heated brackets is another
concern. The surface temperature of a bracket
heated to sufficiently soften the adhesive resin is
reported to reach 150º C, which is extremely high
for oral cavity. Therefore, bracket removal
requires careful attention & expertise on
practitioner part.
3. For safety reasons, continuous force is applied to
debond the brackets. Laser debonding requires
that the bracket be removed immediately after
the adhesive resin has softened to prevent the
laser from damaging the pulpal tissue. During
laser application the technician may apply
continuous force to debond the bracket,
contributing to patients discomfort.

• Kotaro Hayakawa (2005) did a study to develop an
effective method for debonding ceramic brackets
with a high- peak power Nd: YAG laser.
Result showed that application of a high
peak power Nd: YAG at 2.0 J or more is effective
for debonding ceramic brackets. Maximum
temperature rise measured on the pulpal walls at
the lasing points was 5.1º C.


Porcelain surface treatment by
laser for bracket porcelain
bonding
• The demand for adult orthodontic treatment has been
gradually increasing. Because many adult patients
have porcelain crowns & bridges, orthodontist are
faced with the problem of bonding brackets onto
porcelain surfaces.


• Optimal bracket adhesion to a porcelain surface
requires that orthodontic forces be applied without
bond failure during treatment & that the porcelain
integrity not be jeopardized during the debonding
procedure.
• Porcelain is not appropriate for orthodontic bonding
because of the physical properties of glazed surfaces
& the chemical properties of bonding resins.


• Various techniques have been suggested for surface
treatment of porcelain before bonding attachments
including deglazing the porcelain by roughening the
surface with a diamond bur or microetching with
aluminum oxide particles & then bonding the
brackets with or without a coupling agent, &
chemical preparation of the previously deglazed
porcelain surface by etching with orthophosphoric or
hydrofluoric acid & then bonding brackets with or
without a coupling agent.


• However previous studies have indicated that sand
blasting & acid- etching with OFA produces
insufficient bond strength for clinical requirements.
• Bond strength with hydrofluoric acid etching has
been shown to be clinically acceptable but the danger
of acid burns must be considered.


• Studies on the use of silane coupling agent have
presented evidence of increased bond strength of
brackets to porcelain but have also shown the risk
of cohesive failure during debonding.
•

Tolga Akova et al (2005) did a study to investigate
the effect of laser irradiation on the adhesion of
brackets bonded to feldspathic porcelain & compare
it with brackets bonded with conventional
techniques.

•
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.

They compared 10 different groups:Sand blasted (SB)
Sand blasted with silane (SB + S)
Ortho phosphoric acid (OFA)
Ortho phosphoric acid with silane (OFA + S)
Hydro fluoric acid (HFA)
Hydro fluoric acid with silane (HFA + S)
Laser etched (L)
Laser etched with silane (L+S)
Glazed (Control 1/ C1) &
Deglazed (Control 2/ C2)

HFA + S(15.07 ±1.44)
SB+S(13.81 superpulse CO laser
± 2.0)
They concluded that 2watt/ 20 secs
HFA(10.78 ± 0.2)

2

irradiation might be an alternative conditioning method for
pretreating ceramic surfaces. Increased bond strength can be
achieved by silanation after CO2 laser irradiation.
OFA + S(10.73 ± 1.12)

L + S(8.25 ± 0.90)
L(6.27 ± 0.58)
C2(2.45 ± 0.54)
OFA(2.37 ± 0.41)
SB(2.04 ± 0.41)
C1(1.54 ± 0.33)

Effect of laser irradiation on Enamel
Decalcification

• Many previous studies using several types of laser
apparatus including
1. Ruby laser (Sognnaes & Stern 1965; Stern et al
1966),
2. CO2 laser (Stern et al 1972; Nelson et al 1986,
1987),
3. Nd - YAG laser (Yamamoto & Ooya 1974; Moroika
et al 1982, 1984),
4. Krypton laser (Moroika et al 1982), &
5. Argon laser (Goodman & Kaufman 1977; Oho &
Morioka 1987) all reported increased acid resistance
in lased enamel.www.indiandentalacademy.com

AccuCure 3000 argon laser. B.
Fiberoptic curing wand.


• However the mechanism of acid resistance has not
been clarified. Using quantitative microradiography,
argon laser irradiation of enamel reduces the amount
of demineralization by 30 to 50%.
• Fox et al, found that, in addition to decreasing
enamel demineralization & loss of tooth structure,
laser treatment can reduce threshold pH at which
dissolution occurs by about a factor of 5.

• Westerman et al showed that Argon laser treatment
at low fluences could considerably alter the surface
morphology while maintaining an intact enamel
surface.
• A number of studies have also shown that
combining laser irradiation with fluoride treatment
can have a synergistic effect on acid resistance.


• Mechanism of action
The most likely mechanism for demineralization
resistance is through creation of microspores within
lased enamel. During demineralization, acid solution
penetrate into the enamel & result in release of
calcium, phosphorus & fluoride ions. In sound
enamel, these ions diffuse into acid solution & are
released into the oral environment. With lased
enamel, the microspaces created by laser irradiation,
trap the released ions & act as sites for mineral
reprecipitation within the enamel structure. Thus
lased enamel has increased affinity for calcium,
phosphates & fluorides.

• Powell & Hicks, Lloyd Noel (2003), Anderson et al
(2002) have all shown a decrease in enamel
demineralization in orthodontic patients when
treated with lasers.
• However J Elaut & H Wehrbein (2004) did not find
any difference between laser group & control group.


Effect of low level laser therapy in
reducing orthodontic post
adjustment pain
• Low level laser has been shown by many investigators
to provide analgesic effects in various therapeutic &
clinical applications.


• Low level laser therapy (LLLT) is the new
internationally accepted designation & is defined as
laser treatment in which energy output is low enough
so as not to cause a rise in the temperature of the
treated tissue above 36.5º C or normal body
temperature.
• Because of its low energy output & intensity, its
effects are mainly non thermal & biostimulatory.


• The mechanisms of laser analgesia have not been
established, but it has been attributed to its antiinflammatory & neuronal effects.
• It has been proposed by Harris that LLLT has a
benign stimulatory influence on depressed neuronal &
lymphocyte respiration.


• Other neuronal effects include sterilization of
membrane potential & release of neurotransmitters.
• The transmission of laser through tissue is highly
wavelength specific & is most optimal in the optical
window of 500 - 1200 nm.


• Hong - Meng Kim et al (1995) did a study to test the
efficacy of LLLT in controlling orthodontic post
adjustment pain. Visual analogue scale (VAS) was
used to quantify the pain experienced by the subjects
before & after laser application for each day.
• Analysis of VAS median scores showed that teeth
exposed to laser treatment had lower levels of pain as
compared with those in placebo group. However
nonparametric statistical analysis of the data showed
that the difference between treatments & placebo
within each subject were not statistically significant.

Effects of Low power laser
irradiation on bone regeneration
in midpalatal suture
• Rapid palatal expansion (RME) is the preferred
treatment approach to correct a constricted maxillary
dental arch. It is known, however, that a long period
of retention is necessary to prevent early relapse of
the expanded arch.

• Although the reason for the early relapse is not fully
clear, bone regeneration in the midpalatal suture after
expansion may affect the post treatment relapse.
• It would be potentially beneficial therefore to
accelerate bone formation in the midpalatal suture
after expansion to prevent relapse of arch width & to
abbreviate the retention period.


• Shiro Shito & Noriyoshi Shimizu (1997) did a study
to investigate the effects of low power laser
irradiation on bone regeneration during expansion of
midpalatal suture in rats.
• The bone regeneration in the midpalatal suture
estimated by histomorphometric method in the 7 day
irradiated group showed significant acceleration at
1.2 to 1.4 fold compared with the non irradiated rats,
& this increased rate was irradiated dose dependent.

• Irradiation during the early period of expansion was
most effective, whereas neither the later period nor
the one time irradiation had any effect on bone
regeneration.
• These findings suggest that low power laser
irradiation can accelerate bone regeneration in a
midpalatal suture during expansion & that this
effect is dependent not only on the total laser
irradiation dosage but also on the timing & frequency
of irradiation.

Laser welders
• The EBWS-30 is a next
generation, fully
automated, Nd:YAG laser
welding system. This new
product line has been
designed to provide
precision micro welding
capability in a production
environment. While
developed specifically for
joining orthodontic
brackets to their pads, this
turnkey system may be
configured for a wide range
of applications including
the assembly of medical
devices, sensors and the
photonic components used www.indiandentalacademy.com
in telecommunication.

Conclusion
In 1998, a laser-related trade journal printed an
article on laser dermatology indicating that because of
new applications, reduced prices, and instruments
becoming more user-friendly, the dermatology laser
market was becoming a billion dollar industry. If the
same holds true in dentistry keeping in mind that
there are only approximately 7000 dermatologists in
the United States think of the potential for the
dental laser market.

It is huge, but to reach that potential, several criteria
must be met:
– Market penetration must double in the next 4 to 5
years.
– Instrument sizes must diminish.
– Laser prices must decrease to an average of
$10,000 for soft tissue lasers and $25,000 for hard
tissue lasers over the next 10 years.


• Meeting these criteria would generate the necessary
revenues for increased expenditures for research and
development to improve existing delivery systems and
develop new fiber types, continue development of a
short-pulsed hard tissue laser to replace air turbines,
and combine wavelengths into a single package, while
looking into new wavelengths. If all of the abovementioned become a reality in 10 to 15 years, the
growth of the dental laser market could be limitless
because of the hugeness of the worldwide dental
marketplace. The last 20 years have witnessed many
new developments in dental technologies, and the
next 20 years promise to be even richer in technologic
advancements. Lasers will be in the forefront of that
growth.

References
• BJO; 1994, Aug, 21: 308- 312
• JCO 2004; May: 266- 273
• Journal of orthodontics & craniofacial research 2006;
9: 38 - 43
• Angle orthodontist; 70, 1:28 - 33
• Angle orthodontist; 73,3: 249 - 258
• EJO, 1999, 21: 193 -198
• EJO, 2004,26: 553- 560
• BDJ, 2004,196: 413- 418

• Journal of orthodontics & craniofacial research 2001,
4: 3- 10
• AJODO 2002, 122, 2: 342- 348
• AJODO 2005, 128, 5: 638- 647
• AJODO 2002, 122: 251- 259
• Journal of orofacial orthopedics 2001, 5: 375- 386
• AO, 75, 2: 214
• AO, 75, 5: 791
• Journal of orthodontics & craniofacial research 2006,
9: 38- 43
• AJODO 1997, 111: 525- 532

Thank you
Thank You

Leader in continuing dental education


Lasers in Orthodontics: A Brief History and Applications

Empfohlen

Empfohlen

Weitere ähnliche Inhalte

Was ist angesagt?

Was ist angesagt? (20)

Ähnlich wie Lasers in Orthodontics: A Brief History and Applications

Ähnlich wie Lasers in Orthodontics: A Brief History and Applications (20)

Mehr von Indian dental academy

Mehr von Indian dental academy (20)

Kürzlich hochgeladen

Kürzlich hochgeladen (20)

Lasers in Orthodontics: A Brief History and Applications