BACK-GROUND OF CURRENT IMPRESSION MATERIALS
DISADVANTAGES OF CURRENT IMPRESSION TECHNIQUES
EVOLUTION OF DIGITAL IMPRESSIONS
PRE-REQUISITEOF DIGITAL IMAGING
DIGITAL IMPRESSION TECHNIQUES
HOW IT ISDONE?
PROCESSING STEPS IN THEDENTAL PRACTICE:COMPARISON
BENEFITS OF DIGITAL IMPRESSIONS
Today,digitaltechnologycontrolsalmostevery aspectofourlife, anddentistryis noexceptiontoit.
Millions ofimpressions aretakenevery yearforthe productionofcrowns,bridges, andpartialdentures.
Making impressionswith elastomericimpression materialis aneverydayprocedurein almostevery general
A new wayto dispensetraysandimpression materialsis nowavailablethatcreatedigital impressionsofa
The digitalimpression conceptis emerging rapidlyonthe horizonanditis believed thatdigital impressions
willsolvethe challenges anddifficultiesoftheconventionalimpressions.
4. Back-ground of Current Impression
The historyoftoday’straditionalimpressionmaterialsbegan in
the mid-1930’swiththe introductionof reversible hydrocolloids.
This wasthefirstmaterialthatmade theimpression ofundercuts
Therewasagreat improvementin reproducingthe
5. In 1966, further improvements in impression materials occurredwith
the introduction of polyether. This material proved tobefar superior to
the hydrocolloid followed by silicones in 1976.
Though they are hydrophobic by nature buteven in the presence of a
moist environment, they are highly dimensional stable resulting in a
superior elastic recovery.
With the advancement of time and technology improvements are made
to these materials to reduce tearing, chair time and enhance the patient
6. DISADVANTAGES OF CURRENT
Errors in tray selection.
Limitations inthe impression material’s flow and hydrophilicity.
Patient movement .
Tearingand deformation of the impression duringremoval.
Dimensional stability of the set impression.
Inadequate wetting and voids when pouringthe cast.
Tedious and time taking.
Discomfort to patient.
7. Evolution of Digital Impressions
Dr.Duretfirstintroducedthe CAD/CAMconcepttodentistryin 1973in Lyon,Francein his thesis
The conceptofCAD/CAM systemswasfurtherdeveloped byDr.Mormann,aSwiss Dentist,andMr.
Thefirstcommerciallyavailabledigitalimpression systemforusein thefield ofdentistrywas
introducedin 1980pioneered byPROCERAandCEREC.
Over thelast10years,systemslike 3M LavaC.O.S., CadentiTero, E4DDentist,and3ShapeTrioshave
Todate,variousCAD/CAM systemsare nowavailablefordentalapplications.Eachemploysaspecific,
distincttechnique formaking impressions.
usedto create a
Using either a
the tipof the
digital model of
14. Thescanner operates using visible blue light
emanating from light emitting diodes (LEDs)
with shorter wavelengths of light than
previous CEREC models, increasing the
accuracy ofthe scan.
16. Theocclusion is recordedby simply scanning
the arches, and digital on-screenarticulating
papershows where there arecontacts. Images
of interdigitation of the opposing teeth also
show if there is sufficient interocclusal
After the clinician has verified the
digital preparation the CEREC MC XL
milling center can beused to createfull
contour crowns in six minutes.
Alternatively, the MC L Compact
Milling Unit can beused.
TheE4D can beused for all fixed prosthesis except
bridges and implants.
TheE4D has separate scanning and milling units within a
cart, with automated interunit communication.
19. TheE4D (D4D TECHNOLOGIES) takes
several images using a red light laser to
reflect off of the tooth structure, oscillating
at 20,000 cycles per second to capture the
series of images and createa 3-D model.
Thescanner is held at a specific
distance above the tooth, aided by
rubber stops on the scannerhead, and
the area is centered forimaging (aided
by a bull’s-eye on-screenguide).
21. Theocclusion and occlusal height ofmilled
restorations areassessed from the
preparation’s arch and an image of a
physical registration bitehence there is no
requirement toscan the opposing arch.
Themilling component includes a
touch-screenpanel that provides
guidance during the process. The
digital scan is transferred to the milling
machine(with wireless orwired
transmission), and the restoration is
milled from both sides simultaneously.
TheiTero chairside digital impression scanner utilizes parallel confocal imaging
to capture a 3D digital impression of the tooth surface, contours and gingival
Thescanner has the ability to capture preparations for crowns, bridges.
24. LIGHT USED
TheParallel confocal imaging uses laser and
optical scanning to digitally capture thesurface
and contours of the tooth and gum structure. The
Cadent iTero scannercaptures 100,000 points of
red laser light and has perfect focus images of
more than 300 focal depths of the tooth structure.
All of these focal depthimages arespaced
approximately 50 μmapart. This system does not
require the use of powder.
During scanning, a series of visual and verbal
prompts are giventhat are customized for the
patient beingtreated and guide the clinician
through the scanning process. Foreach
preparation, a facial, lingual, mesio-proximal and
disto-proximal viewis recordedin around 15 to
20 seconds, after which the adjacentteeth are
scanned from the facial and lingual aspect.
26. RECORDING OCCLUSION
Theocclusion is captured by taking two interocclusal
views with the patient in centric, after which the
dentist can viewthe image within 30 seconds and
ascertain that the interocclusal clearance is sufficient
for the planned prosthesis prior to the patient leaving.
No bite registration material is required.
Themilling of the models is done on a
5-axis milling machine,using a
proprietary resin material.
Simultaneously, the dental laboratory
technician can export the digital
impression file to his orher CAD/CAM
system and begin fabrication of
copings and/or prosthesis.
29. LIGHT USED
TheLava C.O.S.scanner contains 192 LEDs and 22 lens
systems with a pulsating blue light and uses continuous
video to capture the data that appears onthe computer
touch screenduring scanning. Almost 2,400 data sets
are captured per arch.
After scanning the tooth preparation,
the dentist is able to rotate and
magnify the view on the screenand
can also switch from the 3-D image to
a 2-D view. The full arch is scanned
after the preparation imaging is
complete, followed by the opposing
31. RECORDING OCCLUSION
Theocclusion is assessed by scanning from the buccal
aspect with the teeth in occlusion and viewing the
Theimages aretransmitted directly to laboratory where
the laboratory technician digitally marks the margins
and sections the virtual model priortosending this
digitally to the manufacturer.
33. Differentiation between various camera
CEREC E4D iTero LAVACOS
Full-archdigital impressionsindicated YES NO YES YES
PowderingRequired YES NO NO Some
AcquisitionTechnology Blue light LED Redlight LASER Confocal Bluelight LED
In-OfficeMilling YES YES NO NO
ConnectivitytoLabs YES NO YES YES
RestorationDesign (CAD) Software YES YES NO NO
Indicationforbridges YES NO YES YES
43. Processing steps in the dental practice
Prepare the impression tray
Make silicone impression
Dental laboratory steps
Pour stone material
Fabrication of prosthesis
Acquire digital impression
Complete order form
Data transfer Connect portal
Dental laboratory steps
Confirm receipt of data
Check accuracy ofdata in 3D
44. BENEFITS OF DIGITAL
Accuracy of impressions
Opportunity to view, adjust and rescan impressions
No physical impression for patient
Savestime and one visit for in-office systems
Opportunity to viewocclusion
Accurate restorations created on digital models
Potential for cost-sharing of machines
45. Accurate, wear- and chip-resistant physical CAD/CAM derived models
No layering/baking errors
No casting/soldering errors
Patient is comfortable
46. DISADVANTAGES OF DIGITAL
Digital equipment is very expensive.
Digital equipment’s are complex and trained operator is
required to operate and maintain the device.
Good and up-to- date laboratory support is required.
Those with small mouths may have difficulty with this
With the numerous advantages of
digital impressions over traditional
impressions and the ability to
benefit from digital impression
taking and/or CAD/CAM, more and
more dentists are purchasing digital
impression systems. It will likely be
a routine procedure in most dental
offices in the near future, as
dentists, laboratory technicians, and
patients all reap the benefits.
iData Research Inc., 2007, U.S. Market for Dental Prosthetic
Beuer F, Schweiger J, Edelhoff D. Digital dentistry: an
overview of recent developments for CAD/CAM generated
restorations. Br Dent J. 2008;204(9):505-11.
Nathan S. Birnbaum; Heidi B. Aaronson;Chris Stevens; Bob
Cohen. 3D Digital Scanners: A High-Tech Approach to More
Accurate Dental Impressions; Inside Dentistry; April 2009; 5,
Puri S. Maximizing and simplifying CAD/CAM dentistry;
49. Svend Carlsen. Witnessing the evolution of digital impression solutions; Dental
Tribune U.S. Edition | May 2012
Sabiha S. Bunek, DDS; Chris Brown, BSEE. The Evolving Impressions of Digital
Dentistry ; Inside Dentistry; January 2014
Sankalp Sharma,1 Swatantra Agarwal,2 Divya Sharma,3 Sanjeev Kumar,4
Nishtha Glodha. IMPRESSION; DIGITAL VS CONVENTIONAL: A REVIEW ;
Annals of Dental Specialty Vol. 2; Issue 1. Jan – Mar 2014
Notas do Editor
Transfer to the laboratory is only possible if the laboratory has CEREC CONNECT.