Magnification assisted dentistry

Dr. Ashok Ayer
Department of Conservative Dentistry & Endodontics
College of Dental Surgery, BPKIHS, Dharan, Nepal
‘You can only treat what you can see’

Contents:
Introduction:
A brief history of magnification
Evolution of magnification and illumination in medicine
Evolution of magnification and illumination in dentistry
Loupes
Endoscopy
Dental Operating Microscope
Magnification
Illumination
Accessories
Advantages
Disadvantages
Misconceptions about surgical microscopes
Use of Dental Operating Microscope in endodontic therapy
Conclusion
References

Introduction:
Traditional endodontics has been based on
feel not sight.
Together with radiographs and electronic apex
locators this blind approach has produced
surprising success.
There is, however, a significant failure rate,
especially in long-term. Magnification helps the
user not only to see more, but to see well.

High levels of magnification increase the
aggregate amount of visual information available
to endodontists for diagnosing and treating dental
pathology.
Improved ergonomics and zero defect
endodontics.

Clinically, most dental practitioners will not be
able to see an open margin smaller than 0.2
mm.
The film thickness of most crown and bridge
cements is 25 μm (0.025 mm), well beyond
the resolving power of the naked eye.
Human mouth is a small space to operate in,
especially considering the size of the
available instruments (eg, burs, handpieces)
and the comparatively large size of the
operator’s hands.
Gary B. Carr, Carlos A.F. Murgel. The Use of the Operating Microscope in Endodontics. Dent Clin N Am 54 (2010) 191–214

A dollar bill without magnification.
Note that the lines that make George Washington’s face
cannot be seen in detail.

(A) Magnification 3. (B) Magnification 5. (C) Magnification 8.
Different magnifications of a dollar bill as seen through an
OM.

Magnification 10. Magnification 18.

Several elements are important for consideration in
improving clinical visualization.
 Stereopsis
Magnification range
 Depth of field
 Resolving power
Working distance
 Spherical and chromatic distortion (ie, aberration)
 Ergonomics
 Eyestrain
 Head and neck fatigue
 Cost.

Considering the problem of the
uncomfortable proximity of the practitioner’s
face to the patient, moving closer to the
patient is not a satisfactory solution for
increasing a clinician’s resolution.
As the eye-subject distance (i.e, focal length)
decreases, the eyes must converge, creating
eyestrain.

As one ages, the ability to focus at closer
distances is compromised. “Presbyopia”:
caused by the lens of the eye losing flexibility
with age.
The eye (lens) becomes unable to
accommodate and produce clear images of
near objects.

The nearest point that the eye can accurately
focus on exceeds ideal working distance.
Alternatively, image size and resolving power
can be increased by using lenses for
magnification, with no need for the position of
the object or the operator to change.

A brief history of
magnification
Hans and Zacharias Jansen (1595)
Simple (single lens) and compound (two lenses)
microscopes.
Robert Hooke (1665) Using a compound
microscope, coined the word ‘cell’ while
describing features of plant tissue.

Anton van Leeuwenhoek (1674) produced
single lenses powerful enough to enable him
to observe bacteria 2–3 μm in diameter.
Carl Zeiss, Ernst Abbe, and Otto Schott
devoted significant time to develop the
microscope.

Evolution of magnification and illumination
in medicine
In 1921, Dr Carl Nylen of Germany:
Monocular microscope for operations to
correct chronic otitis of the ear.
The unit had two magnifications of × 10
and × 15 and a 10 mm diameter view of
the field. This microscope had no
illumination.

In 1922, the Zeiss Company (Germany) working
with Dr Gunnar Holmgren of Sweden,
Introduced a binocular microscope for treating
otosclerosis of the middle ear.
This unit had magnifications of × 8–× 25 with field-of-view
diameters of 6–12 mm
The formal introduction of the binocular operating
microscope took place in 1953 when Zeiss
introduced the Opton ear microscope.

Evolution of magnification and
illumination in dentistry
In 1876, Dr Edwin Saemisch, a German
ophthalmologist, introduced simple binocular
loupes to surgery.
Soon after, dentists began experimenting with
loupes to assist in the performance of precision
dentistry and this continued to be the practice
until the late 1970s.

In 1962, Dr Geza Jako, an otolaryngologist,
used the SOM in oral surgical procedures.
In 1978, Dr Harvey Apotheker, a dentist from
Massachusetts, and Dr Jako began the
development of a microscope specifically
designed for dentistry.

In 1980, Dr Apotheker coined the term
‘microdentistry’
The ‘DentiScope’ (1981) was manufactured by
Chayes-Virginia Inc., USA, and marketed by
the Johnson and Johnson Company
Dr Gabriele Pecora gave the first presentation
on the use of the Dental Operating Microscope
(DOM) in surgical endodontics at the 1990
annual session of the American Association of
Endodontists in Las Vegas, Nevada.

Gary Carr (1999):
Introduced a DOM that had Galilean
optics and that was ergonomically
configured for dentistry,
with several advantages that allowed for
easy use of the scope for nearly all
endodontic and restorative procedures.

Loupes
Historically, dental loupes have been the
most common form of magnification used in
apical surgery.
Loupes are essentially two mono-ocular
microscopes with lenses mounted side by
side and angled inward (convergent
optics) to focus on an object.

Oculars (loupes) rely on convergent vision that essentially requires an overlap of two images. This
form of magnification creates increasing problems and eye strain as magnification power increases.
The clinical microscope utilizes a more refined optical system

× 2.5 and × 3.5 dental loupes (Designs for Vision,
Ronkonkoma, NY, USA).

The disadvantage of this arrangement is that
the eyes must converge to view an image.
This convergence over time will create
eyestrain and fatigue and, as such, loupes
were never intended for lengthy procedures.
Most dental loupes used today are compound
in design and contain multiple lenses with
intervening air spaces.

This is a significant improvement over simple
magnification eyeglasses but falls short of
the more expensive prism loupe design.
Prism loupes: are actually low-power
telescopes that use refractive prisms.

Prism loupes produce better magnification,
larger fields of view, wider depths of field, and
longer working distances than other types of
loupes.
Only the Dental Operating Microscope (DOM)
provides better magnification and optical
characteristics than prism loupes.

Depth of field refers to the ability of the lens
system to focus on objects that are both near
and far without having to change the loupe
position.
As magnification increases, depth of field
decreases.

Also, the smaller the field of view, the
shallower the depth of field.
Depth of field is approximately 5 inches (12.5
cm) for a 2x loupe, 2 inches (6 cm) for a 3.25x
loupe, and 1 inch (2.5 cm) for a 4.5x loupe.

The disadvantage of loupes is that × 3.5–×
4.5 is the maximum practical magnification
limit.
Loupes with higher magnification are available
but they are quite heavy and if worn for a long
period of time can produce significant head,
neck, and back strain.

In addition, as magnification is increased, both
the field of view and depth of field decrease,
which limits visual opportunity.
Visual acuity is heavily influenced by
illumination.
An improvement to using dental loupes is
obtained when a fiberoptic headlamp system is
added to the visual armamentarium.

Surgical headlamps can increase light levels as
much as four times that of traditional dental
operatory lights.
Another advantage of the surgical headlamp is
that since the fiberoptic light is mounted in the
center of the forehead, the light path is always
in the center of the visual field.

Loupes are classified by the optical method in which
they produce magnification.
(1) Diopter, flat-plane, single-lens loupe,
(2) Surgical telescope with a Galileian system
configuration (two lens system),
(3) Surgical telescope with a Keplarian system
configuration (prism roof design that folds the
path of light).
Gary B. Carr, Arnaldo Castellucci. The Use of the Operating Microscope in Endodontics.

The diopter system relies on a simple
magnifying lens.
The degree of magnification is usually
measured in diopters.
One diopter (D) means that a ray of light that
would be focused at infinity now would be
focused at 1 meter (100 cm or 40 inches).

A lens with 2 D designation would focus to 50 cm
(19 inches); a 5 D lens would focus to 20 cm (8
inches).
Confusion occurs when a diopter single-lens
magnifying system is described as 5 D.
This does not mean 5x power (5 times the image
size).
5 D: the focusing distance of the eye to the object is
20 cm (less than 8 inches) with an increased image
size of approximately 2x (2 times actual size).

The surgical telescope of either Galileian or
Keplarian design produce an enlarged viewing
image with a multiple lens system positioned
at a working distance between 11 and 20
inches (28-51 cm).
The most used and suggested working
distance is between 11 and 15 inches (28-38
cm).

The Galileian system provides a
magnification range from 2x up to 4.5x and is
a small, light and very compact system.
The prism loupes (Keplarian system) use
refractive prisms and they are actually
telescopes with complicated light paths,
which provide magnifications up to 6x

An example of a Galilean system
Prism loupes.
These loupes have sophisticated
optics, which rely on internal prisms
to bend the light.

Endoscopy
Endoscopy is a surgical procedure whereby
a long tube is inserted into the body usually
through a small incision.
It is used for diagnostic, examination, and
surgical procedures in many medical fields.
Goss and Bosanquet reported that Ohnishi
first used the endoscope in dentistry to
perform an arthroscopic procedure of the
temporomandibular joint in 1975.

Detsch et al. (1979) first used the endoscope in
endodontics to diagnose dental fractures.
Held et al. and Shulman & Leung (1996)
reported the first use of the endoscope in
surgical and non-surgical endodontics.
Bahcall et al. (1999) presented an endoscopic
technique for endodontic surgery.

The endoscopic system consists of a
telescope with a camera head, a light
source, and a monitor for viewing.
The traditional endoscope used in medical
procedures consists of rigid glass rods and
can be used in apical surgery and non-surgical
endodontics.

A 2.7 mm lens diameter, a 70°
angulation, and a 3 cm long rod-lens are
recommended for surgical endodontic
visualization.

A 4 mm lens diameter, a 30° angulation,
a 4 cm long rod-lens are recommended
for non-surgical visualization through an
occlusal access opening.
Flexible fiberoptic orascope
recommended for intracanal
visualization, has a .8 mm tip diameter,
0° lens, and a working portion that is
15 mm in length.
Bahcall J , Barss J. Orascopic visualization technique for conventional and surgical endodontics. Int Endod J 2003: 36: 441–447.

The term orascopy describes the use of
either the rigid rod-lens endoscope or the
flexible orascope in the oral cavity.
Endodontic Visualization System (EVS)
(JEDMED Instrument Company, St Louis,
MO, USA) incorporates both endoscopy
and orascopy into one unit.

Endodontic visualization system utilizing a
fixed rod lens for apical surgery

Clinicians who use orascopic technology
appreciate the fact that it has a non-fixed field
of focus, which allows visualization of the
treatment field at various angles and
distances without losing focus and depth of
field.
Critics of this form of magnification point out
that the images viewed are two-dimensional
and too restrictive to be useful when
compared with the stereoscopic images
provided with loupes or microscopes.

Dental Operating Microscope
(DOM)
Most microscopes can be configured to
magnifications up to × 40 and beyond but
limitations in depth of field and field of view make it
impractical.
The lower-range magnifications (× 2.5–× 8) are
used for orientation to the surgical field and allow
for a wide field of view.
Mid-range magnifications (× 10 –× 16) are used for
operating.

JEDMED V-Series SOM with assistant
binoculars, a three-chip video camera, and
counter balanced arms.
Global G-6 SOM (Global Surgicalt
Corporation, St Louis, MO, USA) with an
enhanced metal halide illumination system.

Zeiss OPMI PROergo (Carl Zeiss Surgical Inc., Thornwood, NY, USA) with
magnetic clutches, power zoom, and power focus on the handgrips.

Higher-range magnifications (× 20 –× 30)
are used for observing fine detail.
The most significant advantages of using
the DOM are in visualizing the surgical
field and in evaluating surgical technique.

Magnification
The magnification possibilities of a
microscope are determined by;
the power of the eyepiece,
the focal length of the binoculars,
the magnification changer factor, and
the focal length of the objective lens.

Diopter settings on the eyepieces adjust for
accommodation and refractive error of the
operator.
As in a typical pair of field binoculars, adjusting
the distance between the two binocular tubes
sets the interpupillary distance.
Binoculars are now available with variable
inclinable tubes from 0° to 220° to accommodate
virtually any head position.

Magnification changers are available in 3-, 5-,
or 6-step manual changers, manual zoom, or
power zoom changers.
Manual step changers consist of lenses that
are mounted on a turret.

Cross-sectional diagram of a
typical 5-step SOM head showing
the turret ring in the body of the
microscope.

The turret is connected to a dial, which is
located on the side of the microscope housing.
The dial positions one lens in front of the other
within the changer to produce a fixed
magnification factor.
Rotating the dial reverses the lens positions
and produces a second magnification factor.

Turning the dial rotates the turret ring inside the body
of the SOM and creates five magnification factors.

Total magnification of a microscope:
TM = (FLT/FLOL) × EP × MV
FLT: Focal length of tube
FLOL: Focal length of objective lense
EP: Eyepiece Power
MV: Magnification Value

The focal length of the objective lens
determines the operating distance between the
lens and the surgical field.
With the objective lens removed, the
microscope focuses at infinity.
Many endodontic surgeons use a 200 mm lens,
which focuses at about 8 in.
With a 200 mm lens there is adequate room to
place surgical instruments and still be close to
the patient.

Increase in the magnification, decreases the
depth of field and field of view.
While this is a limitation for fixed magnification
loupes, it is not a limiting factor with the DOM
because of the variable ranges of magnification.
If the depth of field or field of view is too narrow,
the operator merely needs to back off on the
magnification as necessary to view the desired
field.

Low range Magnification: (×2.5 - ×8).
Orientation of surgical field & allows wide
inspection of the field of view.
Mid range Magnification: (×8 - ×14).
Surgical procedure including curettage of the
granulation tissue, resection of root tip, root –end
preparation, & root –end filling.
High range Magnification: (×14 - ×30).
Observing the finer details & documentation
purposes.
Grossman’s Endodontic Practice. 12th Edition

Illumination
The light provided in an DOM is two to three
times more powerful than surgical headlamps
and, in many endodontists offices.
The light enters the microscope and is
reflected through a condensing lens to a series
of prisms and then through the objective lens
to the surgical field.

After the light reaches the surgical field, it is
then reflected back through the objective lens,
through the magnification changer lenses,
through the binoculars, and then exits to the
eyes as two separate beams of light.
The separation of the light beams is what
produces the stereoscope effect that allows us
to see depth.

Illumination with the DOM is coaxial with the
line of sight.
This means that light is focused between the
eyes in such a fashion that you can look into the
surgical site without seeing any shadows.
Elimination of shadows is made possible
because the DOM uses Galilean optics.

Galilean optics focus at infinity and send
parallel beams of light to each eye.
With parallel light, the operator's eyes are at
rest and therefore lengthy operations can be
performed without eye fatigue.

Galilean optics. Parallel optics enables the observer to focus at
infinity, relieving eyestrain.

Accessories
A beam splitter can be inserted into the
pathway of light as it returns to the operator's
eyes.
The function of the beam splitter is to supply
light to an accessory such as a video camera
or digital still camera.
In addition, an assistant articulating binocular
can be added to the microscope array.

Doctor and assistant at the surgical operating microscope.

Advantages
Manuel García Calderón et al. The application of microscopic surgery in dentistry. Med Oral Patol Oral Cir Bucal 2007;12:E311-6.

1. Increased Visualization:
 Human eye, when unaided by magnification,
has the inherent ability to resolve or distinguish
two separate lines or entities that are at least
200 microns, or 0.2mm, apart.
 Most people cannot refocus at distances closer
than 10 to 12 cm.
 DOM can raise the resolving limit from 0.2 -
0.006 mm

2. Improved Quality and precision of
treatment:
 A microscope at 10× magnification provides
25 times the information compared to that
obtained through the use of entry-level loupes
(2×) and over 10 times that of 3× power
loupes

Shanelec and Tibbets[1998]
Working without magnification, can make
movements that were 1–2 mm at a time.
At 20× magnification, the refinement in
movements can be as little as 10–20 microns
(10–20/1000 of a mm) at a time.
Tibbets LS, Shanelec DA. Periodontal Microsurgery. Dent Clin North Am. 1998; 42:339–359.

Leknius C, Geissberger M. The Effect of Magnification on the Performance of Fixed Prosthodontic Procedures. J Calif Dent Assoc.
1995; 23(12):66–70.
Leknius and Geissberger, [1995] and
Zaugg et al. (2004):
As magnification is incorporated, procedural
errors decrease significantly.
The inclusion of a microscope resulted in
fewer errors than when a set of loupes was
used.
Zaugg B, Stassinakis A, Hotz P. Influence of Magnification Tools on the Recognition of Simulated Preparation and Filling Errors. Schweiz
Monatsschr Zahnmed. 2004; 114(9):890–896.

The figure features 8x convergent magnification
with loupes and a representation of the two images
that the brain receives as the eyes begin to focus.
The figure shows a common occurrence of the
incomplete merging of the images seen through
a pair of loupes
The figure represents
the same case seen
with a clinical
microscope at 24x
original magnification
featuring infinity
corrected optics.
There is no eye strain
and no visual noise.
Loupes magnification at
8x (original
magnification) and
beyond becomes
excruciating for most
clinicians.
David J. Clark. Operating Microscopes and Zero-Defect DentistryJournal canadien de dentisterie restauratrice et de prosthodontie. December 2008

3. Improved & Ideal treatment Ergonomics
The binoculars on many DOMs have variable
inclination.
This means that the operator's head can
develop and maintain a comfortable position.
All stooping and bending is eliminated, thereby
forcing the operator to sit up straight tilting the
pelvis forward and aligning the spine in proper
position.

This positioning should create a double s-curvature
of the spine, with lordosis in the neck,
kyphosis in the mid-back, and lordosis again in
the lower spine.
Such posturing is not possible when the
clinician is wearing a headlamp and loupes or
using an endoscope.
With these devices, there is still the tendency to
bend over the patient, creating poor ergonomics
and developing head, neck, and shoulder strain.

Constant bending over the patient collapses
the diaphragm and may inhibit oxygen
exchange causing fatigue later in the workday.
This is eliminated with the upright positioning
achieved while using the DOM.
Microscopes with a long working distance
allow distance from the patient, reducing the
risk of exposure to aerosols and spatter.

THE LAWS OF ERGONOMICS
Class I motion: moving only the fingers
(A) Fingers waiting for the file.
(B) File placed in between fingers.
(C) Fingers capturing file.

Class II motion: moving only the fingers and wrists
(A) Hand waiting for the instrument.
(B) Fingers and wrist movement receiving the instrument.
(C) Fingers movement receiving the instrument.

Class III motion: movement originating from the elbow
(A) Elbow rested at the stool support.
(B) Supported elbow rotation and instrument apprehension.
(C) Supported elbow rotation to working position.

Class IV motion: movement originating from the shoulder
(A) Professional at the neutral position.
(B) Shoulders, arms, elbows, and hands moving to reach the OM.
(C) OM moved to the ideal position without rotational movement of the waist
Class V motion: movement that involves twisting or bending
at the waist.

Positioning the DOM
In chronologic order, the preparation of the OM involves the
following maneuvers:
Operator positioning
Rough positioning of the patient
Positioning of the OM and focusing
Adjustment of the interpupillary distance
Fine positioning of the patient
Parfocal adjustment
Fine focus adjustment
Assistant scope adjustment.

Operator Positioning
At the 11- or 12-o’clock position
9-o’clock position may seem more
comfortable when first learning to use an
DOM, but as greater skills are acquired,
changing to other positions rarely serves
any purpose.
Clinicians who constantly change their
positions around the scope are extremely
inefficient in their procedures.

The hips are 90˚ to the floor, the knees are 90˚
to the hips, and the forearms are 90˚ to the
upper arms.
The eyepiece is inclined so that the head and
neck are held at an angle that can be
comfortably sustained.
This position is maintained regardless of the
arch or quadrant being worked on.
The patient is moved to accommodate this
position.

The trapezius, sternocleidomastoid, and
erector spinae muscles of the neck and back
are completely at rest in this position.
Once the ideal position is established, the
operator places the OM on one of the lower
magnifications to locate the working area in its
proper angle of orientation.
The image is focused and stepped up to
higher magnifications if desired.

Operatory Design Principles for using
DOM
The organizing design principle using the OM
in the dental operatory should revolve around
an ergonomic principle called circle of
influence.

All instruments and equipment needed for a
procedure are within reach of either the
clinician or the assistant,
Requiring no more than a class IV motion, and that
most endodontic procedures are performed with
class I or class II motions only.

Team work development: doctor and
assistant working erect and
muscularly relaxed.
Adjustable cart allowing access to all
instruments, using only a class III
motion.

Small movement of the chair to the
left (note that patient’s head is tilted a
little to the left
If necessary, the patient’s head is
moved slightly to the right to
compensate chair movement
(Note that the OM was not touched at any time).

Elbow support for doctor and assistant is mandatory to allow the necessary fine
motor skills under constant magnification and muscular comfort throughout the
day.

4. Ease of Proper Digital Documentation
Capabilities;
The video camera mounted on the
microscope's beam splitter sends a real-time
video signal and an unlimited number of
images can be captured or recorded during the
procedure.
These images can then be saved along with
radiographic images and reviewed with the
patient after the surgery.

Digital radiographs and clinical images on 19′ flat panel LCD screen.

5. Increased Ability to Communicate through
Integrated Video
 Mehrabian:
 55% of the understanding that occurs in verbal
communication is through visual cues, and only 7% of
the comprehension comes from the words.
 Useful in providing information both to
patients and to auxiliaries.
Glenn A. van As:Digital Documentation and the Dental Operating Microscope: what you see is what you get: Int J Microdent 2009;1:30–41.

Microscope with Nikon Digital SLR camera on the right side, a Nikon SB-29 ring flash
mounted at the bottom, and a Sony three-chip digital medical-grade cube camera on the
left side.

Disadvantages
Need for specific training: as a DOM has a
restricted working field, 11mm -55mm
An operator using a DOM can see only the tip
of the instruments, and they are used in delicate
movements of small amplitude
High initial cost of the equipment and
instruments

Misconceptions about surgical
microscopes
Magnification:
‘How powerful is your microscope’?
The question really addresses the issue of useable
power.
Useable power is the maximum object magnification that
can be used in a given clinical situation relative to depth
of field and field of view.
‘How useable is the maximum power’? While
magnification in excess of × 30 is attainable, it is of little
value while performing apical surgery.

Working at a higher magnification is extremely
difficult because slight movements by the
patient continually throw the field out of view
and out of focus.
The operator is then constantly re-centering
and refocusing the microscope.

This wastes a considerable amount of time
and creates unnecessary eye fatigue.
Those clinicians who use the endoscope for
apical surgery would also agree that higher
magnifications are for critical evaluation only
and not for operating.

Illumination
There is a limit to the amount of illumination
that an DOM can provide.
As the magnification is increased, there is
decrease in the effective aperture of the
microscope and therefore limit the amount of
light that can reach the surgeon's eyes.
This means that as higher magnifications are
selected, the surgical field will appear darker.

Depth Perception:
Before apical surgery can be performed with an
DOM, the clinician must feel comfortable
receiving an instrument from his assistant and
placing it between the microscope and the
surgical field.
Learning depth perception and orientation to the
microscope takes time and patience.

Use of Dental Operating Microscope
1. Examination, diagnosis, and treatment
planning:
 To identify a microscopic blemish, colour
alteration, tiny amounts of plaque collecting within
the grooves.
 Chalky white demineralization around the
grooves, and tiny amounts of flaking of darkened
carious tooth structure within the crevices of these
grooves.

2. Diagnosis of cracked teeth
 Microfractures and longitudinal fractures
 Cracks in teeth or restorations, craze lines,
wear facets, cracks at slightly elevated
marginal ridges.
Microfracture diagnosed during
orthograde root canal treatment.
Microfracture diagnosed during
microsurgical endodontic treatment

3. Better visualization of pulp chamber, canal
orifices
 Better identify anatomical landmarks, within the
pulp chamber—including the sides,
overhanging remnants of the pulp chamber
roof, initial perforations into the pulp, dentinal
map, canal orifices and,
 To differentiate between the pulp horns and the
main body of pulp within the chamber.

4. During instrumentation:
 The improved ability to see specific canals
allows endodontists to maneuver files into
canal openings with greater efficiency.
 To determine if all canals are accessed and
instrumented properly when a direct view
might be difficult without removing excessive
amounts of coronal tooth structure.

5. Locating hidden canals/canal systems
 Anatomical variations are not as rare or exotic
as is frequently assumed.
 The introduction of the dental microscope and
the associated ability to inspect the root
canals.

6. Identification and removing of Obliterations
and calcifications:
 These signs occur to a greater or lesser extent
in 50% of all teeth, impairing instrumentation
considerably or essentially preventing
treatment of the canal system.
Obliterated canal orifices impair
instrumentation or even prevent root canal
treatment.

7. Identification and removal of Denticles:
 This specific form of calcification is also
encountered very frequently, can block the canal
entrance or even obstruct further instrumentation.
Denticles can be found and negotiate readily with
the help of a DOM
Denticles may block the canal entrance

8. In Open apex cases:
 Modern apexification therapies call for special
treatment techniques and materials, the
manipulation of which is facilitated significantly
under a dental microscope.
9. Perforation repair:

10. Removal of fractured post and
instruments
 The enhanced vision with magnification and
illumination from a microscope allows
endodontist to observe the most coronal
aspects of fractured post and broken
instruments and to remove them without any
major loss of tooth structure and perforations,
the prognosis for preservation of the tooth is
quite good.

11. Apical microsurgery
 Flap design, flap reflection, flap retraction,
 Osteotomy, periapical curettage,
 Biopsy, hemostasis,
 Apical resection, resected apex evaluation, apical
preparation, apical preparation evaluation, drying
the apical preparation,
 Selecting retrofilling materials, mixing retrofilling
materials, placing retrofilling materials,
 Compacting retrofilling materials, carving retrofilling
materials, finishing retrofilling materials,
 Documenting the completed retrofill, and tissue flap
closure.

(A) A selection of flexible mirrors in different sizes and shapes.
(B) Detail of highly reflective mirrors with flexible and flat shafts.

After anesthesia is obtained, micro-scalpels
(SybronEndo, Orange, CA, USA) are used in
the design of the tissue flap to incise delicately
the interdental papillae when full-thickness flaps
are required.
Vertical incisions are made ½ to two times
longer than in traditional apical surgery to
assure that the tissue can be easily reflected
out of the light path of the microscope.

A variety of micro scalpels sized 1-5 used for precise incision.

Flap Design and Suturing
Incising and reflecting soft-tissue flaps are not
high-magnification procedures.
In many cases, they can be performed with the
naked eye or with low-power loupes. Basic
single interrupted stitch suturing can also be
performed with little to no magnification.
While the microscope could be used at low
magnification, little is gained from its use in
these applications.

However, with the introduction of the delicate
papilla base incision, which requires the use of
7-0 sutures and a minimum of two sutures per
papilla microscopic magnification, with a
minimum of × 4.3, is suggested.
The DOM is used at its best advantage for
osteotomy, apicoectomy (apicectomy), apical
preparation, retrofilling, and documentation.
Velvart P. Papilla base incision: a new approach to recession-free healing of the interdental papilla after endodontic surgery. Int Endod J
2002: 35: 453–460.

Access
One of the problems encountered in apical
surgery is gaining physical access to the sight of
infection.
The DOM will not improve access to the surgical
field.
If access is limited for traditional surgical
approaches, it will be even more limited when the
microscope is placed between the surgeon and
the surgical field.

Use of the DOM, however, will create a much
better view of the surgical field.
This is particularly true in diagnosing craze lines
and cracks along the bevelled surface of a root
or when the surgeon is preparing a tiny isthmus
between two canals ultrasonically.

Because vision is enhanced so dramatically,
apical surgery can now be performed with a
higher degree of confidence and accuracy.
Repeated use of the microscope and
concurrent stereoscopic visualization will help
the clinician develop visual imagery of the
various stages of apical surgery, which is
necessary in learning sophisticated surgical
skills.

Because the DOM enhances vision, bone
removal can be more conservative.
Handpieces such as the Impact Air 45™
(SybronEndo), introduced by oral surgeons to
facilitate sectioning mandibular third molars, are
also suggested for apical surgery to gain better
access to the apices of maxillary and mandibular
molars.

When using the handpiece, the water spray
is aimed directly into the surgical field but
the air stream is ejected out through the
back of the handpiece, thus eliminating
much of the splatter that occurs with
conventional high-speed handpieces.
Because there is no pressurized air or water,
the chances of producing pyemia and
emphysema are significantly reduced.

Burs such as Lindemann bone cutters
(Brasseler USA, Savannah, GA, USA) are
extremely efficient and are recommended for
hard-tissue removal.
They are 9 mm in length and have only four
flutes, which result in less clogging.
With the use of an DOM, the Impact Air 45™
and high-speed surgical burs can be placed
even in areas of anatomical jeopardy with a high
degree of confidence and accuracy.

Impact Air 45™ and surgical length bur in close
proximity to the mental nerve × 8.

With the DOM, periapical curettage is facilitated
because bony margins can be scrutinized for
completeness of tissue removal.
Rubinstein and Kim [1999]
Healing in 96.8% of cases in the short term, and
91.5% in the long term follow-up is well beyond the
success rates of conventional apicoectomy
procedures.

There are others such as external cervical
invasive resorption repairs, removing
materials such as solid obturation materials
(silver points and carrier-based materials),
and other resorptive repairs that also benefit
from a microscopic approach.

Restorative Procedures
Caries detected under cusps,
through magnification
Arrows show crack in ceramic restoration
J Minim Interv Dent 2009; 2 (4)
Jose Roberto Moura Jr. Operating microscopes in restorative dentistry: The pursuit of excellence. Int Dent SA 2006; 10(5): 4-11.

Small cavity can be seen in
proximal surface of inferior incisor
Gap can be seen between all
ceramic crowns and preparation at
25 X magnification

Bubble within adhesive being applied
to tooth, if not detected, may prevent
proper hybridization in that spot.
Dental cracks and incomplete
fractures that used to be diagnosed
by symptom basis,

Excess luting cement identified that
can be carefully removed under
proper magnification
Remaining caries visually detected in
gingival margin of proximal cavity

Conclusion
Microscope-enhanced dentistry is changing the
endodontic-restorative protocol, altering the
thought process when determining when to
save or extract a tooth.
Microscopes offer additional methods for caries
assessment and endodontic therapy, moving
the profession closer to zero-defect restorative
dentistry.

With advanced magnification, the additional
visual information afforded to the clinician
with the benefit of shadow-less, coaxial light
combined with infinity corrected optics
enhances the clinician’s ability to create
clean, caries free margins, which, in turn, can
create an optimal restorative seal.

Exact therapy requires exact vision. High-quality
endodontic therapy is the basis for
long-term function and biologic success,
ensuring that patients remain free of pain.
Shift in clinical accuracy from low
magnification ―tactile-driven endodontics
to ―vision-based endodontics is bringing a
revolution to the field of endodontics with
greater success rate.

References:
1. Richard Rubinstein. Magnification and illumination in apical surgery.
Endodontic Topics; 11 (1), pages 56–77, July 2005.
2. Utpal Kumar Das, Subhasis Das. Dental Operating Microscope in
Endodontics-A Review . IOSR-JDMS Volume 5, Issue 6 (Mar.- Apr.
2013), PP 01-08
3. GossA , Bosanquet A. Temporomandibular joint arthroscopy. J Oral
Maxillofac Surg 1986: 44: 614–617.
4. Detsch S , Cunningham W , Langloss J. Endoscopy as an aid to
endodontic diagnosis. J Endod 1979: 5: 60–62.
5. Held S , Kao Y , Well D. Endoscope – an endodontic application. J
Endod 1996: 22: 327–329
6. Shulman B , Leung B. Endoscopic surgery: an alternative
technique. Dent Today 1996: 15: 42–45.

7. Bahcall JK , Di Fiore PM , Poulakidas TK. An endoscopic
technique for endodontic surgery. J Endod 1999: 25: 132–
135.
8.Velvart P. Papilla base incision: a new approach to
recession-free healing of the interdental papilla after
endodontic surgery. Int Endod J 2002: 35: 453–460.
9.Tibbets LS, Shanelec DA. Periodontal Microsurgery. Dent
Clin North Am. 1998; 42:339–359.
10.Leknius C, Geissberger M. The Effect of Magnification on
the Performance of Fixed Prosthodontic Procedures. J Calif
Dent Assoc. 1995; 23(12):66–70.
11.Zaugg B, Stassinakis A, Hotz P. Influence of Magnification
Tools on the Recognition of Simulated Preparation and
Filling Errors. Schweiz Monatsschr Zahnmed. 2004;
114(9):890–896.

12.Cristian Comes, Anca Valceanu, Darian Rusu, Andreea Didilescu,
Alexandru Bucur, Mirella Anghel, Veronica Argesanu, Stefan- Ioan
Stratul: A Study on the Ergonomical Working Modalities Using the
Dental Operating Microscope (DOM). PART I: Ergonomic Principles in
Dental Medicine; TMJ 2008, Vol. 58, No. 3 – 4 [17].
13.Cristian Comes, Anca Valceanu, Darian Rusu, Andreea Didilescu4,
Alexandru Bucur, Mirella Anghel, Veronica Argesanu, Stefan- Ioan
Stratul; A study on the ergonomical working modalities using the dental
operating microscope (DOM ). Part II: Ergonomic Design Elements of
the Operating Microscopes. TMJ 2009, Vol. 59, No. 1 [18].
14.Andreea Didilescu, Cristian Comes, Darian Rusu, Mihai Bucur, Mirella
Anghel, Veronica Argesanu, Stefan-Ioan Stratul; A study on the
ergonomical working modalities using the dental operating microscope
(DOM ). PART III: Ergonomical Features of Contemporary Top Dental
Microscopes Commented; TMJ 2010, Vol. 60, No. 1.
15.Glenn A. van As:Digital Documentation and the Dental Operating
Microscope: what you see is what you get: Int J Microdent 2009;1:30–
41.

16.Nimet Gencoglu, Dilek Helvacioglu; Comparison of the Different
Techniques to Remove Fractured Endodontic Instruments from
Root Canal Systems; Eur J Dent. 2009 April; 3(2): 90–95. [36].
17.Clifford J. Ruddle; Microendodontic NonsurgicaL Retreatment:
Silver Point Removal; Dentistry Today February 1997.
18.David J. Clark. Operating Microscopes and Zero-Defect
DentistryJournal canadien de dentisterie restauratrice et de
prosthodontie. December 2008
19.Jose Roberto Moura Jr. Operating microscopes in restorative
dentistry: The pursuit of excellence. Int Dent SA 2006; 10(5): 4-
11. [J Minim Interv Dent 2009; 2 (4)]
20. Gary B. Carr, Carlos A.F. Murgel. The Use of the Operating
Microscope in Endodontics. Dent Clin N Am 54 (2010) 191–214.
21. Manuel García Calderón et al. The application of microscopic
surgery in dentistry. Med Oral Patol Oral Cir Bucal 2007;12:E311-
6.

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