cad cam in prosthodontics

1. CAD/CAM in Prosthodontics
Dr DEEKSHITHA N G
THIRD MDS
GDC TVM

2. INTRODUCTION
 CAD/CAM -Computer Aided Designing And Computer
Assisted Manufacturing.
 CAD/CAM technology was developed to solve 3
challenges.
 Ensure adequate strength of the restoration, especially for
posterior teeth.
 Create restorations with a natural appearance.
 Make restoration easier, faster, and more accurate.

3. HISTORY
 Dr Patrick J – Father of CAD/CAM
 In dentistry, the major developments of dental
CAD/CAM systems occurred in the 1980s.
 Dr. Duret – developer of Sopha System
 Dr. Moermann - developer of the CEREC system
 Dr. Andersson - developer of the Procera system

4.  Dr. Duret fabricated crowns (1971),made optical
impression of the abutment tooth in the mouth, followed
by designing an optimal crown considering functional
movement, and milling a crown using a numerically
controlled milling machine.

5.  Dr. Moermann, the developer of the CEREC system.
 First commercially designed CAD/CAM
 He directly measured the prepared cavity with an intra-
oral camera, which was followed by the design and
carving of an inlay from a ceramic block using a
compact machine set at chair-side.
 In 1985

6.  Dr. Andersson, the developer of the Procera system
 Fabricated titanium copings by spark erosion and
introduced CAD/CAM technology into the process of
composite veneered restorations.
 Developed as a system with processing center networked
with satellite digitizers around the world for the
fabrication of all-ceramic frameworks.
 1980S

7. USES
 In dental laboratory and the dental office
 For inlays, onlays, veneers, crowns, fixed partial
dentures, metal and zirconia copings, implant abutments,
milled bars and frame works, occlusal splints, surgical
templates, various maxillofacial prostheses, complete
dentures, removable partial dentures, even full-mouth
reconstruction

8. ADVANTAGES
 Reduced labour
 Time effectiveness
 Quality control: The quality of CAD/CAM restorations
is extremely high because measurements and fabrication
are so precise.
 No provisional restorations are required
 Review and correction of preparation

9. DISADVANTAGES
 Complicated data measurement techniques
 Expensive
 length of the learning curve, which may range from a
few days to several months and may result in the loss of
office production and loss of patient treatment time.

10. COMPONENTS
1. A digitalization tool/scanner that transforms geometry
into digital data that can be processed by the computer.
2. Software that processes data and, depending on the
application, produces a data set for the product to be
fabricated .
3. A production technology that transforms the data set
into the desired product.

12. DIGITALISATION TOOL
 It transforms geometry into digital data that can be
processed by the computer.

13. SCANNERS
1) OPTICAL SCANNERS /NON CONTACT/ACTIVE
 It involves the collection of 3D structures in a so-
called ‘triangulation procedure’.
 Eg:
 Lava Scan ST (3M ESPE, white light projections)
 es1 (etkon, laser beam

14. MECHANICAL
SCANNER/CONTACT/PASSIVE
 The master cast is read mechanically line-by-line by means
ruby ball and the three-dimensional structure measured.
 Has high scanning accuracy, whereby the diameter of the
ruby ball is set to the smallest grinder in the milling system
 Eg:The Procera Scanner from Nobel Biocare
(Only mechanical scanner in dentistry)

15. DRAWBACKS OF THE SYSTEM
 The apparatus is very expensive
 Long processing times compared to optical systems

16. DESIGN SOFTWARE
 With such softwares, various dental restorations can be
constructed.
 The software available on the market is being continuously
improved
 The data of the construction can be stored in various data
formats. The basis therefore is often Standard Transformation
Language (STL) data.
 Many manufacturers, however, use their own data formats,
specific to that particular manufacturer.

18. PRODUCTION TECHNOLOGY
Van Noort classified CAM systems according to methods of manufacturing

19. MILLING
 The construction data produced with the CAD software
are converted into milling strips for the CAM-processing
and finally loaded into the milling device.

20. MILLING
Processing devices are distinguished by means of the
number of milling axes:
 3-axis devices
 4-axis devices
 5-axis devices

21. 3-AXIS MILLING DEVICES
Movement in the three
spatial directions, and so
the mill path points are
uniquely defined by the
X -, Y -, and Z –
Short milling times
simplified control
Less costly inLab (Sirona), Lava (3M ESPE),
Cercon brain (DeguDent

22. 4-AXIS MILLING DEVICES
 In addition to the three spatial axes, the tension bridge
for the component can also be turned infinitely variably
 As a result it is possible to adjust bridge constructions
with a large vertical height displacement into the usual
mould dimensions and thus save material and milling
time.
 Example: Zeno (Wieland-Imes)

23. 5-AXIS MILLING DEVICES
5-axis milling device
has the possibility of
rotating the milling
spindle (5th axis)
milling of complex
geometries with
complex shapes such
as denture base resins
Laboratory Area: Everest Engine (KaVo
Production Centre: HSC Milling Device (etkon)

24. Dry
processing
Wet
milling
MILLING
VARIANTS

25. DRY PROCESSING
Zirconium oxide blanks with a
low degree of pre-sintering
 Minimal investment costs for
the milling device
 No moisture absorption by the
die ZrO2 mould
× Higher shrinkage values for the
frameworks
Zeno 4030 (Wieland- Imes), Lava Form and
Cercon brain

26. Wet
milling
milling diamond
or carbide cutter
is protected by a
spray of cool
liquid
all metals and
glass ceramic
material
zirconium oxide
ceramic with a
higher degree of
pre-sintering is
employed for the
milling process
Everest (KaVo), Zeno 8060 (Wieland-Imes),
inLab (Sirona).
 Reduction of
shrinkage factor
 Enables less sinter
distortion

27. SPARK EROSION
 Electric discharge machining (EDM)
 It is a metal removal process using electric current under
carefully controlled conditions. It is used for precise and
accurate fabrication in the field of fixed, removable and
implant prostheses.
 Can achieve accurate passive fit.

28. SPARK EROSION
 Metal sub/super structures and porcelain veneered
frameworks
 Implant abutments
 Swivel latch attachments,
 Precision attachments,
 Friction pins,
 Titanium copings
 Telescopic crowns

29. ADDITIVE MANUFACTURING
3D PRINTING
RAPID PROTOTYPING

30. TYPES
Laser powder
forming techniques
Stereolithography
(SLA)
Inkjet printing
technologies
Fused deposition
modelling (FDM)
Selective electron
beam melting
SLS(DMLS)
SLM

31. LASER POWDER FORMING
TECHNIQUES
 A scanning laser fuses a fine material powder, to build
up structures layer by layer, as a powder bed drops down
incrementally, and a new fine layer of material is evenly
spread over the surface.
 A high (60μm) level of resolution may be obtained,
 The structures that are printed are supported by the
surrounding powder, no support material is required.

33. Fabrication of :
• Anatomical study models,
• Cutting and drilling guides,
• Dental models,
• Engineering/design prototypes

34. STEREOLITHOGRAPHY
(SLA)
 In 1986 by Charles W. Hull
 A method for making solid objects by successively
printing thin layers of an ultraviolet curable material one
on top of the other.(Hull)
 A liquid photocurable resin acrylate material is used.

35. Rapid fabrication.
Complex shapes with high feature
resolution.
Lower cost materials if used in bulk
Only available with light curable liquid
polymers.
Resin - messy , irritant by contact and
inhalation.
Limited shelf life.
Can not be heat sterilized.
High cost technology

36. FUSED DEPOSITION MODELLING
(FDM)
 First 3DP technology, most used in 'home' printers.
 Thermoplastic material extruded through nozzle onto
build platform

37. Uses
 To produce intermediary wax patterns for subsequent casting
 Patient‐specific implants
 Eg :- complex mandibular models used for reconstructive surgery
 Ceramic paste in the form of a filament or wire - used to fabricate
 dental restorations

39. SELECTIVE ELECTRON BEAM MELTING
 For producing near net shape metal parts.
 The technology manufactures parts by melting metal
powder layer per layer with an electron beam in a high
vacuum.

40. Advantages 1. Porous mesh or foam structures
2. High speed.
3. Dense parts with controlled porosity.
4. High temperature process, so no
support or heat treatment needed
afterwards
5. Less post-processing required.
Disadvantages 1. Extremely costly technology
2. Dust may be hazardous to health.
3. Explosive risk.
4. Rough surface.
5. Lower resolution.

41. INKJET PRINTING TECHNOLOGIES
 Inkjet printers are capable of printing at a very high
resolution by ejecting extremely small ink drops.
 Inkjet printing works by propelling individual small
droplets of “ink” toward a substrate.

42. USES
 Dental Models
 Orthodontic Bracket Guides
 Surgical Guides For Implant Placement
 Mouth Guards
 Sleep Apnea Appliances
 Veneers
 Colored Soft Tissue Prostheses

43. Additive techniques
• Relatively fast.
• High-resolution, high-quality finish
• Multiple materials available including elastic materials
• various colours and physical properties.
• Lower cost technology
Advantages
Disadvantages
• Tenacious support material can be difficult to remove completetly.
• Can not be heat sterilized.
• High cost materials.

44.  Currently, subtractive milling is the most widely
implemented in dentistry and it has been shown to be a
suitable method for fabricating intraoral prostheses.
 Additive methods have the advantage of producing large
objects, with surface irregularities, undercuts, voids, and
hollow morphology that makes them suitable for
manufacturing facial prostheses and metal removable
partial denture frameworks.

45. CLASSIFICATION
In-office system
• This system can scan the tooth
preparation intraorally and by
selecting appropriate materials.
• The dentist can fabricate the
restorations and seat it within a
single appointment
Laboratory based
system
• The indirect systems scan
a stone cast or die of the
prepared tooth, in the
dental lab .
• Many of this system
produce copings which
require the dental
technician to add
aesthetic porcelain
• Dcs
president,procera,cerec
inlab,lava
• Cercon,only has CAM
,WITHOUT DESIGN
1.CAD/CAM for out
sourcing
• New technologies using
CAD/CAM combined with
network machining center
that is outsourcing the
framework fabrication
using an internet

46.  A number of different manufacturers are providing
CAD/CAM systems that generally consist of a scanner,
design computer and a milling machine or 3-D printer.
Laboratories are able to receive digital impression files
from dentists or use a scanner to create digital models
that are used for restorations designing or CAD. Dental
scanners vary in speed and accuracy. Milling machines
vary in size, speed, axes, and also in which restorative
materials can be milled; in this category milling
machines could be classified as wet or dry depending if
the materials require irrigation.

47. COMMERCIALLY AVAILABLE CAD/CAM SYSTEMS
CEREC
The Lava Chairside Oral Scanner (COS)
Procera
CELAY system
Cercon
CICERO system
DCS Preciscan

48. CEREC
 Chairside Economical Restoration of Esthetic Ceramics
 1987
 First dental system to combine digital scanning with a milling
unit.
 Provide single visit ceramic restorations
 CEREC, only has in-office and laboratory-based systems.
 CEREC 1 and CEREC 2 – optical scan of the prepared tooth
with a charged-coupled device (CCD) camera, and the system
automatically generates a 3D digital image on the monitor Then,
the restoration is designed and milled

49. CEREC 3D
 Record multiple images within seconds.
 This enables the clinicians to prepare multiple teeth in the same
quadrant and create a virtual cast for the entire quadrant.
 On the virtual model, the operator designs the contour of the
restoration and electronically transmits the data to a remote
milling unit for fabrication.
 Better marginal adaptation

51. Introduced
in 2009
To take half-arch or full-
arch impressions and
create crowns, veneers, and
bridges

52. CEREC inLab
 Laboratory-based system
 Working dies are laser-scanned and a digital image of the
virtual model is displayed on a computer screen.
 After designing the coping or framework, the laboratory
technician inserts the appropriate ceramic block into the
CEREC inLab machine for milling.

53.  After milling, the technician manually inspects and verifies
the fit of the milled coping or framework on the die and
working cast.
 The coping or framework then is either glass-in filtrated
(Vita In-Ceram) or sintered (zirconium oxide or aluminium
oxide), and the veneering porcelain is added .
 A wide range of high strength ceramic blocks are available
for the inLab system.
inCoris ZI (zirconium oxide) and inCoris AL (aluminium
oxide) (Sirona Dental Systems, LLC).

55. Procera/AllCeram
 1994
 First system to provide fabrication of restoration using a
network connection.
 Uses an innovative concept for generating alumina and
zirconia copings.
 The master die is scanned and the data is send to the
processing center.
 After processing, the coping is send back to the lab for
porcelain veneering.
 According to research data average marginal gap for Procera
all Ceram restoration ranges from 54 μm to 64 μm

57.  Nobel Biocare USA LLC has introduced various implant
abutments for its Procera system
 titanium (1998)
 alumina (2002)
 zirconia (2003)
 Capable of generating alumina (two to four units) and
zirconia (up to 14 units) bridge copings.
 The occlusal-cervical height of the abutment should be at
least 3 mm, and the pontic space should be less than 11 mm

58. DCS Preciscan
 Comprised of a preciscan laser scanner and precimill
CAM multitool milling center.
 It can scan 14 dies simultaneously and mill up to 30
framework units in a single, fully automated operation.
 It can mill titanium as well as fully dense sintered
zirconia.

60. CERCON (2002)
 Used for the production of zirconia - based prostheses
 Wax pattern (coping) with a minimum thickness of 0.4
mm are made ,scanned and the Cercon Brain milling unit
milled a zirconia coping from presintered zirconia
blanks.
 Veneering porcelain was used to provide the esthetic
contour.
 In 2005, DENTSPLY Ceramco introduced the Cercon
Eye 3D laser optical scanner and Cercon Art CAD
design software.

61. Now, Cercon can produce single units and bridges up to
nine units from pre-sintered zirconia milling blocks that
are offered in white and ivory shades without any
infiltration required.

62. Lava
 Lava system introduced in 2002.
 It includes a mobile cart, a touch screen display and a
scanner with camera at the end.
 Camera has LEDs and lens systems
 Data-send through wireless to the laboratory where the
die is cut and margins are marked digitally

64. Lava C.O.S (2008)
 For chairside digital impression making.
 Scanner contains 192 LEDs and 22 lens systems with a
pulsating blue light.
 It uses continuous video to capture the data that appears
on the computer touch screen during scanning .
 2,400 data sets are captured per arch.
 Images can be directly transmitted to an lab.

66. MATERIALS
 Materials for processing by CAD/CAM devices depends
on the respective production system .
 Some milling devices are specifically designed for the
production ZrO2 frames, while others cover the
complete palette of materials from resins to glass
ceramics and high performance ceramics.

68. METALS
Titanium, titanium alloys and chrome cobalt alloys
Precious metal alloys no economic interest, due to the
high metal attrition and the high material costs
coron (etkon: non-precious metal alloy)
Everest Bio T-Blank (KaVo, pure titanium

69. RESIN MATERIAL
 Use resin materials directly as crown and FPD frameworks for
long-term provisional prostheses.
 Prefabricated semi-individual polymer blanks (semi-finished)
with a dentine-enamel layer are provided by one manufacturer
(artegral imCrown, Merz Dental).

70.  The first commercial resin composite for CAD/CAM –
Paradigm MZ100(3M ESPE )

71.  repair of resin-composite crowns could be accomplished
by preconditioning by sand-blasting or bur-roughening,
followed by the placement of a resin-composite with
very similar mechanical and optical properties.
Moreover, resin-composite materials may be less
susceptible to chipping during the milling procedure. it
is possible to use resin materials directly as crown and
FPD frameworks for long-term provisional or for full
anatomical long term temporary prostheses.

72. SILICA BASED CERAMICS
 Grindable silica based ceramic blocks are offered by several
CAD/CAM systems for the production of inlays, onlays,
veneers, partial crowns and full crowns .
 It is usually available as monochromatic blocks.
 Various manufacturers now offer blanks with multicoloured
layers [Vitablocs TriLuxe (Vita), IPS Empress CAD Multi
(IvoclarVivadent)], for the purpose of full anatomical crowns.

73. Due to their higher stability values, lithium disilicate ceramic blocks
are particularly important in this group
Lithium disilicate ceramic blocks
 Full anatomical anterior and posterior crowns
 Copings in the anterior and posterior region
 Three-unit FPD frameworks in the anterior region
(high mechanical stability of 360 mpa)

74.  Glass ceramics are well suited to chairside application due to
their translucent characteristics, similar to that of the natural
tooth structure.
 Provides esthetically pleasing results without veneering.

75. INFILTRATION CERAMICS
 Grindable blocks of infiltration ceramics are processed in
porous, chalky condition and then infiltrated with lanthanum
glass.
 All blanks for infiltration ceramics originate from the Vita In-
Ceram system (Vita)
I. Vita In-Ceram Alumina (Al2O3)
II. Vita In-Ceram Zirconia (70% Al2O3, 30% ZrO2)
III. VITA In-Ceram Spinell (MgAl2O4)

76. Vita In-Ceram
Alumina (Al2O3)
• Crown copings in
the anterior and
posterior region
• Three-unit FPD
frameworks in the
anterior region
Vita In-Ceram
Zirconia (70%
Al2O3, 30% ZrO2)
• Crown copings in
the anterior and
posterior region
• Three-unit FPD
frameworks in the
anterior and
posterior region.
• Discolored teeth
due to its superior
masking ability
VITA In-Ceram
Spinell (MgAl2O4):
• Highest
translucency of all
oxide ceramics.
• Production of
highly aesthetic
anterior crown
copings on vital
abutment teeth and
in the case of
young patients.

77. Yttrium stabilised zirconium
oxide (ZrO2, Y-TZP)
 Zirconium dioxide is a high-performance oxide ceramic
with excellent mechanical characteristics.
 Framework material for crowns and fpds ,individual
implant abutments.
 Examples of zirconium oxide blocks:
Lava frame (3m espe), cercon smart ceramics (degu-dent),
everest zs und zh (kavo), incoris zr (sirona), in-ceram yz
(vita), zerion (etkon) and zeno zr (wieland-imes)

78. EVOLUTION OF WORK FLOW OF
CAD/CAM SYSTEM
 1st Generation of CAD/CAM systems

79.  The intraoral abutment is scanned by an intraoral
digitizer to obtain an optical impression. Digitized data
is reconstructed on the monitor as a 3-D graphic and
then the optimal morphology of the crown can be
‘virtually designed’ on the monitor. The final crown is
fabricated by milling a block using a numerically
controlled machine.

80. 2nd generation of cad/cam systems

81.  Different digitizers such as a contact probe, laser beam
with a PSD sensor, and a laser with a CCD camera were
developed. Sophisticated CAD software and compact
dental CAD⁄CAM machines were also developed.
Consequently, both metallic and ceramic restorations
were able to be fabricated by the second-generation
CAD⁄CAM systems

82. 3rd Generation of CAD/CAM systems

83.  Since these high strength industrial ceramics were not
available to conventional dental laboratories, the
application of networked CAD⁄CAM in a processing
centre was innovative in the history of dental
technology. Such networked production systems are
currently being introduced by a number of companies
worldwide.The production of zirconia frameworks has
become very popular in the world market. The zirconia
framework is fabricated using a CAD⁄CAM process in the
machining centre, final restorations are completed by
veneering conventional porcelain using conventional
manual dental technology by dental technicians.

84. 4th Generation of CAD/CAM systems

85.  Because of rapid progress in new technologies,
especially optical technology, new intraoral digitizers
are now available. The application of dental CAD⁄CAM
systems is expected to shift to the fourth generation, as
illustrated.

86. LIMITATIONS
 The restricted measuring conditions in the mouth, including
the presence of adjacent teeth, gingiva, and saliva, which
made accurate recognition of the margin of an abutment
difficult.
 CAD/CAM milling procedures may induce surface and
subsurface flaws that may adversely affect the strength of this
ceramic.
 the strength can be restored by polishing the material with
rubber wheels and diamond paste. Further enhancement of
strength (to approximately 160 MPa) can be acquired by a
combination of polishing and glazing.

87.  Some CAD/CAM systems, (3M Lava C.O.S. CEREC
Bluecam) require the application of titanium dioxide or
magnesium oxide powder to the abutment teeth before
scanning in order to eliminate reflection and create a
measurable surface.
 The powder layer on the tooth surface results in an
additional thickness of 13-85 μm.
 Regardless of the digitizing mode applied, clinical
parameters such as saliva, blood, or movements of the
patient can affect the accurate reproduction of teeth.
 Limited full arch accuracy of digital impressions as
compared with conventional impressions.

88. CONCLUSION
 As Duret Stated “The systems will continue to improve
in versatility, accuracy, and cost effectiveness, and will
be a part of routine dental practice in coming time”. The
future of dentistry to a great extent will be influenced by
CAD/CAM systems.

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