This document discusses virtual impressions and stereolithographic models in dentistry. It provides a brief history of dental impressions, describes recent digital impression technologies like iTero and CEREC, and discusses how digital impressions can eliminate lab steps and provide benefits like accuracy. It also covers virtual model technologies like stereolithography, how they work using layer-by-layer additive manufacturing, and their applications in areas like implant planning and prosthodontics. The conclusion reiterates that while digital technologies provide benefits, traditional impressions still have roles and digital methods have limitations like equipment costs.

1. VIRTUAL IMPRESSIONS AND
VIRTUAL AND
STEREOLITHOGRAPHIC
MODELS
GUIDED BY- PRESENTED
BY-
DR. ASHISTARU SAHA(HOD) DR. POOJA
AGRAWAL
DR. ANUPAM PURWAR(READER)
DR. TUSHAR TANWANI (READER)
DR. PRANAY MAHASETH (READER)

2. CONTENT-
 Introduction
 Brief history of impressioning in
dentistry
 Advanced technologies
 Benefits of digital impression
 Disadvantages of digital impression
 Virtual models
 Rapid prototyping technologies
 Stereolithography
 Conclusion

3.  A JOURNEY TO THE SUCCESSFUL
PROSTHESIS STARTS WITH A PERFECT
IMPRESSION

4. IMPRESSION

5. IMPRESSION
 a negative likeness or copy in reverse
of the surface of an object;
 an imprint of the teeth and
adjacent structures for use in dentistry

6. Brief history of impressioning
in dentistry
 Impression compound around 1910

7. 1925 Alphous pollerintroduced
AGAR

8. ALGINATE

9. POLYSULFIDE
 Introduced in late 1950s.

10. POLYETHER
 Introduced in1965

11. CONDENSATION SILICONE

12. ADDITION SILICONE

13. ELIMINATING STEPS AT THE
OFFICE
Tray Selection Dispensing Materials Setting of Materials
Disinfection Shipping

14. ELIMINATING STEPS AT THE
LAB
Pouring Plaster Base and Pin Die Cutting
Trimming Articulation

15. ADVANCED
TECHNOLOGIES
 Using Three-dimensional (3D)
digitizing scanners

16. CAD/CAM SYSTEMS
 originated in the 1950s
 The introduction of CAD/CAM
concepts into dental applications was
the brainchild of Dr. Francois Duret

17. DR. FRANCOIS DURET

18. BASED ON THE LOCATION OF
PROCESSING UNIT
 Chairside Production
 Laboratory Production
 Centralised fabrication in production
centre

19. Chairside digital impression
systems with laboratory transfer
capability
 i-Tero Lava C.O.S CEREC AC

20. CEREC

23. CEREC
 acronym for Chairside Economical
Restoration of Esthetic Ceramics
 3D digital scanner with a milling unit to
create dental restorations from
commercially available blocks of
ceramic material in a single
appointment.

24.  With this system, the impressioning
process necessitates achieving
adequate visualization of the margins of
the tooth preparation by proper tissue
retraction or troughing and hemostasis.
 The entire area being impressed needs
to be coated completely with a layer of
biocompatible titanium dioxide powder to
enable the camera to register all of the
tissues.

25. E4D DENTIST

26. E4D DENTIST
 an acronym for Dream, Design,
Develop, Deliver
 It consists of a cart containing the
design center (computer and monitor)
,laser scanner, a separate milling unit,
a job server and router for
communication.

27. DEDICATED IMPRESSION
SCANNING SYSTEMS
 iTero
 Lava C.O.S.

28. iTERO

31. iTERO
 digital impression system -introduced
in early 2007.
 The iTero system includes a computer,
monitor, mouse, integrated keyboard,
foot pedal, and scanning wand
organized on a well-designed mobile
cart.

32.  After all scans (at least 21) are
completed, the dentist steps on the
foot pedal and, within a few minutes,
the digital model is displayed on the
monitor.
 Digital data are sent wirelessly to
Cadent, where the digital impression
is refined and a hard plastic model is
milled.

33.  Cadent then returns the model to the
local dental laboratory, which
completes the final restoration.

34. LAVA C.O.S.

35. LAVA C.O.S.
 The Lava Chairside Oral Scanner
(C.O.S.) was born out of the research
of Professor Doug Hart and Dr. János
Rohály at the Massachusetts Institute
of Technology.
 The Lava C.O.S. unit consists of a
mobile cart, containing a computer, a
touch screen monitor, and a scanning
wand.

36.  Lava C.O.S. requires only enough
powdering to allow the scanner to
locate reference points. Therefore a
very light dusting of powder is
required, and is produced using the
powdering gun provided with the unit.

37.  After all the scans have been
reviewed for accuracy, the dentist
uses the touch screen monitor to
complete an on-screen laboratory
prescription.
 The data is sent wirelessly to the
laboratory technician, who then uses
customized software to cut the die and
mark the margin digitally.

38.  At the model manufacturing facility, a
stereolithography model is generated,
and is sent to the laboratory, where
the technician creates the final
restoration.

40. CEREC E4D iTero LAVA COS
Full-arch Yes No Yes Yes
Powder Yes Yes No Yes
In-Office Milling Yes Yes No No
Connectivity to Labs Yes No Yes Yes
In-Office Designing Yes Yes No No
Bridge 3 unit No Full Yes
Focal Distance Any 15 mm
iTero Vs. CEREC, E4D, & Lava COS

41. RECENT ADVANCES

42. BENEFITS OF DIGITAL
IMPRESSIONS
 Digital impressions eliminate the
uncomfortable experience of making a
physical impression.
 Digital impressions are an incredible
teaching tool because you can
evaluate your preparation on a 19-inch
monitor.

43.  The image on the monitor shows you if
you have captured all the needed data
before sending it to the lab.
 The accuracy of the mounting, bite
registration, and stability of the dies
create a model that allows the laboratory
technician to fabricate a final restoration
that has excellent marginal fit and
incredibly accurate occlusion.

44. DISADVANTAGES OF DIGITAL
IMPRESSIONS
 At this time, there is limited ability to
use this system for implant
impressions.
 Head size & weight of camera or
intraoral scanner.
 Cost

45. VIRTUAL MODELS

46. RAPID PROTOTYPING
 The term rapid prototyping (RP)
refers to a class of technologies that
can automatically construct physical
models from Computer-Aided Design
(CAD) data.
 These "three dimensional printers"
allow designers to quickly create
tangible prototypes of their designs,
rather than just two-dimensional
pictures.

47.  The key idea of this new RP
technology is based on the
decomposition of three-dimensional
computer models in the layers section
transverse thin, followed physically
forming layers and piling layer by
layer.

48. All RP techniques employ the same basic five-
step process.
1. Scan and create a CAD model of the design
2. Convert the CAD model to STL format
3. Slice the STL file into thin cross-sectional
layers
4. Construct the model one layer over the
other
5. Clean and finish the model

49.  STL file – Standard Triangulation
Language file
STL is a file format native to the
stereolithography CAD software created
by 3D Systems.
it is widely used for rapid prototyping and
computer-aided manufacturing

50. Layer by layer addition

51. DICOM FILES
 Digital Imaging and
Communications in
Medicine (DICOM) is a standard for
handling, storing, printing,
and transmitting information in medical
imaging. It includes a file
format definition and a
network communications protocol.

52.  DICOM files can be exchanged
between two entities that are capable
of receiving image and patient data in
DICOM format.
 Applications-
 radiography,
 ultrasonography,
 computed tomography (CT),
 magnetic resonance imaging (MRI)

53. CT scan MRI scan

54. INVESALIUS
 InVesalius is a free medical software used to
generate virtual reconstructions of structures
in the human body. Based on two-
dimensional images, acquired using
computed tomography or magnetic
resonance imaging equipment,
 the software generates virtual three-
dimensional models correspondent to
anatomical parts of the human body. After
constructing three-
dimensional DICOM images, the software
allows the generation
of STL (stereolithography) files. These files
can be used for rapid prototyping.

55.  The software’s name is a tribute to
Belgian physician Andreas
Vesalius (1514–1564), considered the
"father of modern anatomy"

56. Rapid Prototyping Technologies
 Stereolithography (SL)
 Laminated Object Manufacturing (LOM)
 Selective Laser Sintering (SLS)
 Fused Deposition Modeling (FDM)
 Inkjet (thermal phase change)

57. STEREOLITHOGRAPHY

58. STEREOLITHOGRAPHY (SL)
 This system consists of a bath of
photosensitive liquid resin, a model-
building platform, and an ultraviolet
(UV)
laser for curing the resin.
 The first process of this type of RP
was patented by Charles Hull (1984).

59.  The layers are cured sequentially and
bond together to form a solid object
beginning from the bottom of the model
and building up.
 As the resin is exposed to the UV light, a
thin well-defined layer thickness
becomes hardened.
 After a layer of resin is cured, the resin
platform is lowered within the bath by a
small known distance (typically 0.003-
0.002 in).

60.  A new layer of resin is wiped across
the surface of the previous layer using
a wiper blade, and this second layer is
subsequently exposed and cured.
 The process of curing and lowering
theplatform into the resin bath is
repeated until the full model is
complete.

61. • The self-adhesive property of the
material causes the layers to bond to
each other and eventually form a
complete, en bloc 3D object.
• The model is then removed from the
bath and cured for a further period of
time in a Uv cabinet.

62. MATERIALS USED
 1. Accura Bluestone-nano-
composite material
 2.SOMOS® NeXt-resin
 3. SOMOS® 18420 -epoxy resin,
medical & dental use.
 4. SOMOS® 9120-epoxy resin
 5. WaterShed® XC 11122-
liquid photopolymer

63. APPLICATION
 fabrication of surgical drilling
templates during dental implant
insertion.

64. LAMINATED OBJECT
MANUFACTURING

65. SELECTIVE LASER
SINTERING

66. FUSED DEPOSITION
MODELING

67. INKJET (THERMAL PHASE
CHANGE)

68. STEREOLITHOGRAPHY
MODELS
Three-dimensional (3D) Computerized axial tomography
(CAT) of a pediatric patient (A), stereolithography models of
the
same patient made with C. Acrylic (B, C).

69. USE OF STEREOLITHOGRAPHY IN
RESTORING A CASE OF MAXILLOFACIAL
DEFECT
3dMDfaceTM System.

70. Patient seated at 3dMDfaceTM.

71. Picture of patient taken with 3dMDfaceTM.

72. Altered photo frontal position.

73. Color model made with the ZPrinter R 450 and
high performance composite material.

74. Clear model made with the SLA 7000 and UV light-
activated epoxy resin.

75. Clay sculpture on model

76. Patient and final prosthesis without glasses

77. Patient and final prosthesis with glasses

78. MIRROR-IMAGE WAX
PATTERN OF AN EAR
Cast of
remaining ear

79. 3-D images of
remaining ear and
mirror image. Image at
top right represents
mirror image of
remaining ear.

80. Thermoplastic (wax)
pattern of missing ear
produced from cast of
remaining ear.

81. Image of wax pattern and cast of remaining ear
projected in front of mirror to explain concept of technique.

82. CONCLUSION
 These optical impressions are
superior in technology and known for
its accuracy, saves the patients and
dentists time with a few laboratory
procedures and patients comfort
 but it has limitations like high cost, and
specialised equipment requirement

83.  As part of their upgrade process,
general
dentists must possess a basic
knowledge about the applications and
advantages of new 3D modeling
technologies used in dentistry, such as
those of stereolithography, an
exceptional support
tool for designing surgical treatment
and implant placement.

84. REFRENCES-
 Shruti S. Bammani a, 1, Pranav R. Birajdarb, 1 and Shriniwas
S Metanc, Dental Crown Manufacturing using
Stereolithography Method, Proc. of Int. Conf. on Advances in
Industrial and Production Engineering 2012
 Ma. del Socorro Islas Ruiz¹; Miguel Ángel Noyola Frías DDS²;
Ricardo Martínez Rider DDS²;Amaury Pozos Guillén DDS,
PhD 3; Arturo Garrocho Rangel DDS, PhD, Fundamentals of
Stereolithography, an Useful Tool for Diagnosis in Dentistry,
 V. N. V. Madhav1 , Rajendra Daule, Rapid Prototyping and its
Application in Dentistry, Journal of Dental & Allied Sciences
2013;2(2)57-61
 Gary M. Radz, DDS, Clinical impressions of digital
impressions,
www.dentaleconomics.com

85.  Nathan S. Birnbaum, DDS; and Heidi B. Aaronson, DMD,
Dental Impressions Using 3D Digital Scanners: Virtual
Becomes Reality
 Majd Al Mardini, DDS,a Carlo Ercoli, DDS,b and Gerald N.
Graser, DDS, MSc University of Rochester Eastman Dental
Center, Rochester, NY, A technique to produce a mirror-image
wax pattern of an ear using rapid prototyping technology
 Jennifer V. Sabol, DDS, MS,1 Gerald T. Grant, DMD, MS,2
Peter Liacouras, PhD, MS,3 & Stephen Rouse, DDS3, Digital
Image Capture and Rapid Prototyping of the Maxillofacial
Defect
 Internet

86. THANK YOU