CAD CAM ESENTIALS

1. PRESENTED BY:
SYED MUKHTAR-UN- NISAR ANDRABI
ASSISTANT PROFESSOR
CONSERVATIVE DENTISTRY & ENDODONTICS
CAD- CAM IN RESTORATIVE DENTISTRY

2. Introduction
 CAD/CAM is an acronym for computer-aided
design/computer-aided manufacturing.
 With CAD/CAM, parts and components can be designed and
machined with precision using a computer with integrated
software linked to a milling device.
 CAD/CAM technology was introduced to dentistry in 1988 in
Germany and is widely used today to generate tooth-colored
fillings (Machined Restorations) that are bonded to front and
back teeth.
 CAD/CAM can be used for making fillings chairside in the
dental office or for fabricating restorations in a dental
laboratory.

3. Introduction (contd.)
 The science of CAD/CAM dentistry has expanded rapidly in the last few years.
 The types of restorations possible using such systems are almost as varied as the
dentists who embrace them.
 The chairside CAD/CAM system is approaching 20 years of clinical experience and
has a proven track record on all relevant aspects of clinical performance, including
fit, longevity and survival rates, sensitivity, strength, and wear.

4. Vv
 The two principal machining approaches for dental restorations are:
 (1) copy milling and
 (2) CAD/CAM milling.

5. Copy Milling
Copy milling uses a replica
(e.g., wax, plastic, stone, or
metal) of the desired form
as a guide for a milling
machine.
The surface of the replica is
traced by turning the
pattern and touching the
patterns surface with a
finger stylus.
The positions of the pattern
and stylus are used to
adjust the positions of a
block of machinable
material and a milling tool
cutting the block,
respectively.

6. CAD-CAM
Milling
CAD/CAM milling uses
digital information about
the tooth preparation
(computerized surface
digitization [CSD]), or a
pattern of the restoration
to provide a computer-
aided design (CAD) on the
video monitor for
inspection and
modification.
Once the three-
dimensional image for the
restoration design is
accepted, the computer
translates the image into a
set of instructions to guide
a milling tool (computer-
assisted manufacturing
[CAM]) in cutting the
restoration from a block of
material.

7. History
 The earliest attempt to apply CAD/CAM technology to dentistry
began in the 1970s with
 Bruce Altschuler, in the United States,
 Francois Duret, in France, and
 Werner Mormann, and Marco Brandestini in Switzerland.
 Duret developed the Duret system, which was later marketed as the
Sopha Bioconcept system demonstrating the ability of CAD/CAM to
generate single-unit, full-coverage restorations. However, this
system was not successful in the dental market because of its
complexity and cost.
 Mormann and B r a n d e s t i n i : first commercially available dental
CAD/CAM system was CEREC (Sirona Dental Systems)

8. History
 Today’s CAD/CAM systems – both chair-side and laboratory-based– are being
used to design and manufacture metal, alumina, and zirconia frameworks, as
well as all-ceramic and composite for:
 crowns, inlays, and veneers that may be stronger, fit better, and are more
esthetic than restorations fabricated using traditional methods.

9. Procedure
 When creating a chairside CAD/CAM filling, the dentist
 Makes a digital picture of the prepared tooth containing three-
dimensional information about the size of the tooth and defect
being restored, as well as the adjacent teeth.(digital impression)
 Designs the desired filling directly on a computer screen using
CAD/CAM software. (CAD)
 A tooth-colored block of ceramic or composite material is
machined by fine diamond drills to produce the designed filling.
(CAM)
 The CAD/CAM filling is then tried in the mouth, adjusted,
polished, and bonded in place with a composite resin bonding
cement.

11. Digital Impression Or Data Capture
 Data capture differs remarkably between commercially
available dental CAD/CAM systems.
 Intraoral digital 3-D scanning device (digitizer): directly scans
tooth preparations intra-orally. Integral component of some
CAD-CAM devices such as CEREC-3D & Evolution 4D. Works in
combination with dedicated CAD software.
 Disadvantage : exceptionally sensitive to any motion. Slight
movement of a patient during data acquisition would
compromise the quality of the data, ultimately leading to a
restoration that would not fit.
 Extra-oral digitizers: capture data from models

12. Restoration Design (CAD)
 Several CAD software programs are available commercially for designing
virtual 3-D dental restorations on a computer screen.
 The software programs usually are proprietary to the CAD/CAM system and
cannot be interchanged among systems.
 Operator has the option to modify the automatically designed restoration to
fit his or her preferences.
 When the design of the restoration is complete, the CAD software transforms
the virtual model into a specific set of commands.

13. Restoration Fabrication (CAM)
 CAM uses computer-generated paths to shape a part.
 Early systems relied almost exclusively on cutting the
restoration from a prefabricated block with the use of burs,
diamonds or diamond “subtractive method”.
 “additive” CAM approaches (also called “solid free-form
fabrication”), instead of cutting, the system sinters material
along the design path created, building a part from a “bath” of
ceramic or metal powder and adding material continually until
the complex part is complete.
 No excess material remains.
Selective Laser sintering technology

14. BONDING of CAD-CAM
 Bonding of ceramic CAD/CAM restoration is a critical step in achieving good
long-term results:
(1) etching enamel to increase the bondable surface area;
(2) etching, priming, and applying the bonding agent to dentin (when
appropriate);
(3) etching (by HF acid) and then priming (silanating) the restoration; and
(4) cementing the restoration with composite cement.

16. Common CAD/CAM Systems
 CAD/CAM systems may be categorized as
 In-office Or Laboratory Systems
 Among all dental CAD/CAM systems, CEREC is the only manufacturer that
provides both in-office and laboratory modalities. Similar to CEREC is the
Evolution D4D
 Laboratory CAD/CAM systems include:
 DCS Precident,
 Procera,
 CEREC inLab, and
 Lava.
 Evolution D4D
 Everest
 Cercon is a laboratory system that possesses only CAM capabilities
without the design stage.

19. CEREC SYSTEM
 CEREC -1, CEREC- 2, CEREC- 3D, CEREC inLab
 With CEREC 1 and CEREC 2, an optical scan of the prepared tooth is made
with a couple charged device (CCD) camera, and a 3-dimensional digital
image is generated on the monitor.The restoration is then designed and
milled.
 With the newer CEREC 3D, the operator records multiple images within
seconds, enabling clinicians to prepare multiple teeth in the same quadrant
and create a virtual cast for the entire quadrant.

20. CEREC SYSTEM
 CEREC inLab is a laboratory system in which working dies are laser-scanned
and a digital image of the virtual model is displayed on a laptop screen.
 After designing the coping or framework, the laboratory technician inserts
the appropriate VITA In-Ceram block into the CEREC inLab machine for milling.
The technician then verifies the fit of the milled coping or framework. The
coping or framework is glass infiltrated and veneering porcelain is added.

21. CEREC SYSTEM
 In vitro evaluation of CAD/CAM ceramic crowns that compared the marginal
adaptation of CEREC 2 with CEREC 3D concluded that crown adaptation for
CEREC 3D (47.5 ± 19.5 μm) was significantly better compared with CEREC 2
(97.0 ± 33.8 μm).
(Ellingsen LA, Fasbinder DJ. In vitro evaluation of CAD/CAM
ceramic crowns [abstract 2640]. J Dent Res. 2002;81:331)

22. DCS Precident
 The DCS Precident system is comprised of a Preciscan laser
scanner and Precimill CAM multitool milling center.
 The DCS Dentform software automatically suggests connector
sizes and pontic forms for bridges.
 It can scan 14 dies simultaneously and mill up to 30
framework units in 1 fully automated operation.
 Materials used with DCS include porcelain, glass ceramic, In-
Ceram, dense zirconia, metals, and fiber- reinforced
composites.
 This system is one of the few CAD/CAM systems that can mill
titanium and fully dense sintered zirconia.

23. Procera
 Procera/AllCeram was introduced in 1994
 Generates alumina and zirconia copings.
 First master die is scanned and then an enlarged virtual die is
made to meet the sintering shrinkage of the porcelain.
 Sintering at 2,000°C imparts maximum density and strength to
the milled copings.
 The complete procedure for Procera coping fabrication is very
technique-sensitive because the degree of die enlargement
must precisely match the shrinkage produced by sintering the
alumina or zirconia.

24. LAVA
 Introduced in 2002, Lava uses a laser optical system to digitize
information from multiple abutment margins and the
edentulous ridge.
 The Lava CAD software automatically finds the margin and
suggests a pontic.
 The framework is designed to be 20% larger to compensate for
sintering shrinkage.
 The computer- controlled precision milling unit can mill out 21
copings or bridge frameworks without supervision or manual
intervention.
 Milled frameworks then undergo sintering to attain their final
dimensions, density, and strength

25. Everest
 Marketed in 2002, the Everest system consists of scan, engine, and therm
components.
 Its machining unit has 5-axis movement that is capable of producing detailed
morphology and precise margins from a variety of materials including leucite-
reinforced glass ceramics, partially and fully sintered zirconia, and titanium.
 Partially sintered zirconia frameworks require additional heat processing in its
furnace.

26. CERCON
 The Cercon System is commonly referred to as a CAM system because it does
not have a CAD component.
 In this system, a wax pattern (coping and pontic) with a minimum thickness of
0.4 mm is made.
 The system scans the wax pattern and mills a zirconia bridge coping from
presintered zirconia blanks.
 The coping is then sintered in the Cercon heat furnace (1,350ºC) for 6 to 8
hours.
 A low-fusing, leucite-free Cercon Ceram S veneering porcelain is used to
provide the esthetic contour.

27. Marginal Integrity of CAD/CAM
Restorations
 One of the most important criteria in evaluating fixed
restorations is marginal integrity.
 Evaluating inlay restorations, Leinfelder and colleagues
reported that marginal discrepancies larger than 100 μm
resulted in extensive loss of the luting agent.
 Christensen suggested a clinical goal of 25 μm to 40 μm for the
marginal adaptation of cemented restorations.
 Most clinicians agree that the marginal gap should be no
greater than 50 μm to 100 μm
 Current research data indicate that most dental CAD/CAM
systems are now able to produce restorations with acceptable
marginal adaptation of less than 100 μm

28. ADVANTAGES DISADVANTAGES
 Excellent flexural strength
 Ability to rigidly bond to the
remaining tooth structure
 Repairable if damaged
 Inability to produce excellent
esthetics- they are monolithic i.e
restn is milled from a block of
single shade.
 Technique sensitivity
 High cost of the equipment
Clinical Considerations

29. CONCLUSION
 CAD/CAM systems have dramatically enhanced dentistry by providing high-
quality restorations.
 The evolution of current systems and the introduction of new systems
demonstrate increasing user friendliness, expanded capabilities, and
improved quality, and range in complexity and application.
 New materials also are more esthetic, wear more nearly like enamel, and are
strong enough for full crowns and bridges.

30. Thank
you