application of intra-oral scanner in fixed prosthodontics: Intraoral scanning, a cutting-edge advancement in dental technology, is rapidly transforming the landscape of modern dentistry. This innovative approach eliminates the need for traditional impression materials, which can often be messy, time-consuming, and uncomfortable for patients. The Intraoral Scanner is a device used to digitally record topographical features of teeth and surrounding tissues. It produces 3D scans for later use in computer- assisted design and computer- assisted manufacturing of dental restorations.

1. Applications Of Intra- Oral
Scanners( IOS) In Crown
And Bridge
Done by Ahmed Ali Jasim

2. Introduction :
Intraoral scanning, a cutting-edge advancement in dental
technology, is rapidly transforming the landscape of
modern dentistry. This innovative approach eliminates
the need for traditional impression materials, which can
often be messy, time-consuming, and uncomfortable for
patients.

3. What is Intra- oral scanner (IOS)?
The Intraoral Scanner is a device used to digitally
record topographical features of teeth and
surrounding tissues. It produces 3D scans for later
use in computer- assisted design and computer-
assisted manufacturing of dental restorations.

4. Brief History Of Intraoral
Scanners:
•1987: The first intraoral scanner, the “CEREC
1,” was introduced by Dentsply Sirona
developed by Dr. Mormann & Dr.Brandestini
• 1990s - 2000s : Intraoral scanners became
more popular as the technology improved. The
“CEREC AC” is example of this period
 It used a video camera and reflective powder
to create a 3D model of the teeth,
 slow and required a lot of manual labor.

5. Brief History Of Intraoral Scanners:
•In the mid-2000s: Intraoral scanners began to use “confocal
microscopy” This allowed for faster and more accurate scanning.
•In the late 2000s: Intraoral scanners continued to evolve and improve,
with some scanners using “triangulation”
•The 2010s: Intraoral scanners became more widely used in dentistry,
and several companies began to offer different types of scanners. Some
scanners used “structured light” to capture the 3D shape of the teeth,
while others used Active wave-front sampling cameras to create a 3D
model.

6. What are the imaging technology employed in
IOS?
The imaging technology which are most commonly used in are:
Confocal laser scanning:
Triangulation technique:
Active wave-front sampling (3D-in-motion video recording):

7. What are the imaging
technology employed in
IOS?
•Confocal laser scanning: The
emitting laser is projected
through a filter with a tiny pinhole
to the target. only the confocal
light reflected from the object in
focus is being captured. Out-of-
focus data are not recorded, thus
improving accuracy. This imaging
process is also known as “point-
and-stitch reconstruction.” iTero
and TRIOS are the two scanners
that use this technique.

8. What are the imaging technology
employed in IOS?
•Triangulation technique: it has long
been used in the CEREC system .
CEREC projects a light on the object. As
each light ray is reflected back on the
sensor, the distance between the
projected and reflected ray is measured.
Because the fixed angle between the
projector and sensor is known, the
distance to the object can be calculated
through Pythagoras theorem, as one
side and one angle (the fixed angle) of
the triangle are now known. Hence the
name “triangulation”.

9. What are the imaging technology
employed in IOS?
•Active wave-front sampling (3D-in-
motion video recording): This optical
sampling method used by Lava
Chairside Oral Scanner (COS) and True
Definition that employs three cameras
and an off-axis aperture, The single-lens
circles around a point of interest around
the optical axis. Theoretically, AWS
imaging allows any system with a digital
camera to function in 3D through complex
logarithm.

10. What are Light Projection and Capture
Passive techniques
Passive techniques only use ambient lighting to enlighten intraoral
tissues, which are highly dependent on the object’s texture.
Active techniques
For active techniques, however, the camera projects white, red or
blue structured lights onto the surface of the object. It is less reliant
on the real texture and color of tissues for reconstruction.
 Points emission
In this way, a luminous point is projected onto an object and the
distance is calculated by triangulation.
 Network emission (structured light)
This means light pattern projection. A video can take several images
per second in a continuous data flow and then reconstruct the
object’s surface.

11. The operating methods
of intraoral scanners
Image stitching scanners record
individual images, they have a field of
view in the form of a cone, so they
cannot collect information from those
hidden surfaces, hence necessary to
make several shots of the same area to
collect all the information.
Video-sequencing Scanners
record the scanned areas working
similarly as a video camera through
sequential short videos at high speed.

12. What IOS are used for?
• Single Custom Abutment
• Inlays & Onlays
• Single Crown
• Veneer
• 3unit Implant Bridge
• Multiple Unit FPD Bridge
• Orthodontics
• Implant Guide
• Diagnosis Model

13. Contraindications of IOS
IOS are not intended to be used to create
images of the internal structure of teeth
or the supporting skeletal structure.

14. What are The intraoral scanner
key components?
– Camera: The scanner is equipped
with a high-resolution camera that
captures images of the teeth and
gums. Advanced scanners use
multiple cameras to capture different
angles simultaneously, ensuring
comprehensive coverage.
– Light Source: Most scanners use
a light source, often in the form of a
laser or structured light, to illuminate
the oral cavity and enhance the
clarity of the captured images.

15. What are The intraoral scanner key
components?
Display unit : A wireless / wired mobile workstation
to support data entry. Many modern intraoral
scanners come with an dedicated integrated
touchscreen display, other scanners use a computer
monitor to enter instructions, approve scans and
review digital files.
Software: The heart of the intraoral scanner is its
software. It processes the captured images, stitches
them together, and creates the 3D digital model.
Advanced software can also offer features like color
mapping, measurement tools, and integration with
other dental software systems for treatment planning.

16.  Advantages of digital impression
 For dentist & technician: save time & effort
(ergonomics)
✓ No need for:
▪ Tray selection
▪ Material mixing & setting
▪ Impression disinfection, packaging & shipping
▪ Cast pouring, setting & trimming
▪ Die cutting
▪ Articulation

17.  Advantages of digital impression
Patient comfort
Reduce gag reflex
✓ No waiting until the
material sets
✓ No retake of the full
impression

18.  Advantages of digital impression
 Dentist / lab. communication
electronically (time saving )
 Accuracy comparable to
conventional impression scanner
 Evaluation, corrections &
rescanning
 ▪ Instant display on screen
 ▪ Interrupted & resumed at any time
 ▪ Digital magnification of the image
up to 20 times, which facilitates
evaluation
 ▪ Rescanning of missing &
unacceptable areas only

19. Disadvantages Of Digital Impression
 Cost
 Expensive cost of purchase and maintenance
 Yearly Fees (Subscription Fees)
 Updates & upgrades are often required
Powder spray in some models
 Relatively uncomfortable to the patient
 May be harmful to respiratory tract
 Thickness: inhomogeneous thickness may slightly change the tooth
outline
Camera (Scanner Wand) size: may be a concern for some patients.
note: if there is sufficient vertical space to a dental handpiece, there will
be sufficient space for an intraoral scanner.

20. Disadvantages of digital impression
Presence of saliva or blood which do not allow the prober of digital
impression capturing (scanning) Note: the camera can record what is
visible to the operator eye.
Scan Depth Limitations: While intraoral scanners are adept at capturing
surface details, they may have limitations in scan depth. This can be a
challenge when trying to capture deep subgingival preparations or
areas with significant tissue overhang.

21. Disadvantages of digital impression
Impossible in some situations
Functional impression: which selectively presses the tissues
Border molding: impression of the maximum vestibular depth
Fogging: slows & interferes with the scan.
Cracks on the scanner tip after repeated sterilization:
Slow the scan speed
Require replacement of the scanner tip

22. Disadvantages of digital impression
Patient Movement: Just like with traditional methods, patient movement
can affect the quality of the scan. However, since scanning is generally
quicker and more comfortable than traditional impressions, patients are
less likely to move during the process.
Reflectivity and Transparency: Highly reflective surfaces, such as metal
restorations or transparent materials like clear orthodontic aligners, can
sometimes pose challenges for certain scanners. However,
advancements in scanning technology and software algorithms are
continually improving the capture of such surfaces.

23. Disadvantages of digital impression
Learning Curve: While intraoral scanners are designed
to be user-friendly, there’s still a learning curve
involved. Proper positioning and angulation of the
scanner are crucial for optimal results. Over time, with
practice, dental professionals can master the
technique to consistently obtain high-quality scans.

24. Types of intraoral scanners
The most common types are
 Open & closed systems
 Scan with/without design software & in-office mill
 Powder coating & powder-free scan

25. Open system Closed system
Export open files Export proprietary files
Can be used by any design software & other
CAD/CAM systems
Used only by the same manufacturer software
& CAD/CAM system
Examples
✓ STL (monochrome) files
✓ Colored files (PLY or OBJ)
Examples
✓ Proprietary files produced by older
generations of CEREC & E4D intraoral
scanners
Note: Recent scanners are now open systems
(export open files)
Note: The manufacturer offers all CAD/CAM
procedures, including:
✓ Digital impression (intraoral scanner)
✓ Virtual design (CAD software)
✓ In-office milling (CAM)

26. Powder coating
✓ Older generations of some intraoral
scanners require coating of teeth
surfaces (shiny) with opaque Titanium
Dioxide powder.
Aim
✓ Reduce reflectivity
✓ Uniform light dispersion
✓ Improve scan accuracy
Precautions
✓ Powdering requires a dry field
✓ Avoid unnecessary build-up of
material, as it can affect accuracy

27. Powder coating
 Disadvantages
✓ Relatively uncomfortable
✓ May be harmful to respiratory tract
✓ Thickness: inhomogeneous thickness may slightly change the
tooth outline
Examples of intraoral scanners which required powder coating
✓ CEREC (Sirona, Germany): 1987
✓ Lava C.O.S (3M ESPE, Germany): 2008
Recently, scanning powder is no longer required for the
majority of intraoral scanners.

28. Difference between digital and traditional work
flow

29. Digital Work Flow

30. Scanning procedure
 Prepare the Intraoral Scanner
• Connect different components according
to device type check proper connection
• Make sure the scanning wand and
attached mirror are clean and disinfected
before each use. Carefully inspect for
any residual debris or fogginess on the
mirror.
• Warm up the tip before beginning to
scan.
 If you do not give the scanner enough
time, the scan tip will start to fog and
scanner will not be able to scan properly.
The specific warm-up time depends on
the weather and room temperature.

31. Practice
Dentists new to a
scanner system are
recommend scanning
plastic models before
practicing on patients.

32. Tooth preparation matters.
Your preparation significantly affects the quality of your
scans, particularly regarding margins. Try a Shoulder
Prep for a clean margin finish and a robust platform
underneath a crown or bridge to minimize margin issues.
Chamfer and Shoulder Bevel are also acceptable, but
Knife and Feather Edge are not due to a lack of clear
margins. Also, double cord retraction is best, but if you
have one adequately sized cord, that works, too. Paste
and Laser retraction can also work and helps avoid
washed margins.

33.  Prepare the Patient
• Before you start scanning, make sure your patient is
comfortable and understands the process.
• At the scan, always recommend that the patient brush
and floss to remove plaque and food present on/in
between the tooth surfaces and in the areas
surrounding the gums.
• Remove any removable appliances such as dentures
or retainers
• clean and dry the patient's teeth to ensure there are
no blood, saliva or food that could interfere with the
scan.
• it is critical to isolate soft tissue properly to keep the
area clear from contaminants that would interfere in
data capture. Moisture also creates glare and
distortions in the scan. Use the air-water syringe and
suction before and during the scan to dry the teeth
and gums.

34. Lighting
Scans, like photography, require
excellent lighting. Therefore, turning off
any external light sources, like loupe
lights and overhead chair lights, is
essential. The scanner has an internal
light that will be best for capturing the
dental pictures needed for the scan.
Any excess light can interfere with this
process, creating a glare on the
intraoral photos that makes images
unclear.

35. Adjust Your Scanning Posture
To achieve a good scanning, your
scanning posture matters. You should
decide whether you prefer to stand at
the front or sit at the rear while
scanning your patient. Next, adjust your
body position to match the dental arch
and the area you are scanning. Make
sure that your body is positioned in a
way that allows the scanner head to
remain parallel to the area being
captured at all times.

36. Holding the scanner
The camera should be held in a range
of between 5 and 30mm of the
scanned surface depending on the
scanners and technologies .
after removing the scanner’s
protective tip and replacing it with the
mirror tip, its recommend holding the
sensor like a pencil, letting it rest in the
pocket of your thumb and index finger,
with the power button accessible
easily on the top. Then, you can
switch the mirror tip to facing up or
down from this position, depending
upon which arch you are scanning.

37.  Step 4: Starting the Scan
Starting at one end of the teeth (either the
back of the upper right or upper left side),
press on switch hearing a click , shutter music
etc. noise indicate device start recording
slowly move the scanner from tooth to tooth.
Ensure that all surfaces of each tooth are
scanned, including the occlusal , buccal , and
lingual surfaces. It's important to move slowly
and steadily to ensure a high-quality scan.
Remember to avoid sudden movements,
as they can cause the scanner to lose
track.
The mirror can be flipped to scan
opposing arches

38.  Step 4: Starting the Scan
The recommended scanning protocol
(scan path) consists of 3 sweeps:
occlusal, lingual, and buccal to ensure
good data.
some software might display a path
operator must follow
The scanner camera is aligned with the
occlusal surface. Swings the scanner
from side to side during the scan,
bringing over the lingual and buccal
sides. Slowly wiggle the scanner when
passing the centrals. Move your scanner
smoothly without jumping around. Pay
attention to areas where soft issue may
interfere with scan when scan the buccal
side.

39. The Twist Technique
To capture hard to reach areas like
interproximal areas and contact points around
your prep, try incorporating an alternative
scanning approach called the Twist Technique.
Capturing interproximal areas:
•Place the scan on the occlusal surface of the
prep.
•Roll the scanner over to either the buccal or
lingual sides.
•Position the scanner at a 45-degree angle.
•Twist the scanner back and forth to fill in
missing areas around the prep; it is crucial to
twist and hold, pause, then twist and hold in the
other direction, pause.
•Ensure the light hits the hard-to-reach areas; if
the light touches it, the camera is, too.

40. The Twist Technique
Capturing contact points:
•Place the scanner on the occlusal surface.
•Rotate the scanner out 90 degrees.
•Twist the scanner back and forth to fill in missing areas
around the prep; again, it is crucial to twist and hold,
pause, then twist and hold in the other direction, pause.
•Ensure the light hits the hard-to-reach areas.

41. Pre-prep Scan
Scan the patient's teeth prior to
prepping. This is because your
lab can use this scan data as a
base when designing the
restoration, it will be easier to
create a restoration that is as
close as possible to the shape
and contour of the original tooth.
The Pre-prep scan is a very
useful function as it increases the
accuracy of the work done.

42. Scanning the Opposing Arch
Once you've scanned the entire upper arch, you'll need to
scan the opposing lower arch. Ask the patient to open their
mouth wide and position the scanner to capture all the teeth
from the back to the front. Again, ensure that all tooth
surfaces are properly scanned.

43. Capturing the Bite
After scanning both arches, you'll
need to capture the patient's bite.
Ask the patient to bite down in their
natural, comfortable position. Scan
the area where the upper and
lower teeth meet, ensuring you
capture the relationship between
the two arches.
Alignment could be automatic or
manual.

44. Check for Any
Missed Areas
Review the scanned
model on the scanner
screen and look for any
gaps or missing areas.
If needed, rescan any
problem spots before
moving on. It's easy to
rescan to complete the
missing data.

45. Review & Finalize the Scan
Take a final look at the complete 3D
model on the scanner screen to
confirm everything looks accurate
and aligned. Make any small touch-
ups if needed before finalizing and
exporting the scan file. You can use
the scanner software's editing tools
to clean up the scan and remove any
unnecessary data.

46. Saving & Sending to Lab
After reviewing and making sure the scan is perfect, save it in
the appropriate format. Most intraoral scanners will allow you to
save the scan as an STL file. You can then send this file to your
partner dental lab for the fabrication of dental restorations, or
use it for treatment planning.

47. Maintenance and Upgrades: How to Ensure Optimal
Performance?
– Regular Cleaning: One of the most fundamental maintenance routines is the
regular cleaning of the scanner tip. After each use, it’s crucial to clean the tip with the
recommended disinfectant solution to prevent cross-contamination and ensure clear
imaging.
– Calibration: Over time, the scanner’s accuracy might drift slightly. Regular
calibration, as advised by the manufacturer, ensures that the scanner captures
accurate and consistent data. Some scanners come with self-calibration features,
while others might require manual calibration using specific calibration tools.
– Software Updates: Just like computer or smartphone, intraoral scanners operate
on software that occasionally needs updates. These updates can fix bugs, improve
performance, or add new features. It’s essential to keep the scanner’s software up-
to-date to ensure optimal functionality.
– Physical Inspections: Periodically, it’s a good idea to inspect the scanner for any
signs of wear, damage, or loose components. This includes checking the scanner tip,
cables, and any moving parts.

48. Recent advances of intraoral scanners
✓ Speed: fast scanning, fast full arch scan (under 45 seconds)
✓ Size & weight: smaller scanner tips & light-weight scanners
✓ Color: high definition (HD) color image life-like & realistic
✓ Touch-screen
✓ Portable (tablet)
✓ Wireless, such as TRIOS 4 & CS 3800
✓ USB option (laptop scanner): can be used with any laptop
✓ Anti-fog (defogging): prevent fogging of the scanner window
(mirror)
✓ Caries detection: such as iTero Element 5D Plus, TRIOS 4 and
Planmeca Emerald S
✓ Shade determination: such as TRIOS 3, TRIOS 4, CS 3700 & CS
3800

49. Recent advances of intraoral scanners
✓ Smile design
✓ More depth of scan: allow accurate scans of deep margins
✓ Open system: scanners are now open, export open files
▪ Can be used by other design software
▪ Such as STL (monochrome) or colored files (PLY or OBJ)
✓ Price: less expensive scanners
Smart Filtering that recognizes the difference between hard
dentition elements, teeth, and soft tissue in dental pictures,
removing unnecessary tissue from the scan data based on
movement.