CAD/CAM in prosthetic dentistry

 Successful dental prostheses should be durable, esthetic,
accurate comfortable to the patient.
 Conventional fabrication methods involve (recording impression,
pouring stone model, construct wax pattern, investing, replaced
with permanent material such as metal, ceramic, acrylic or
silicone).
 considerable human intervention , manipulation of materials
(inherent processing shrinkage or expansion processing
errors, inaccuracies, time and cost, require considerable skills.
 Reducing the reliance on the human variable and use of
automated design and fabrication techniques would therefore
facilitate the production of more reliable prostheses

 1971 Dr.Duret- Sopha System (crowns)
 1985 Dr. Moermann- CEREC® system (inlay)
 1980s Dr. Andersson- Procera® system (titanium
copings and composite veneered restorations)
This system later developed as a processing center networked with
satellite digitizers around the world for the fabrication of all-ceramic
frameworks.
4

 In office- scan, fabricate and seat within
same appointment.
 CAD/CAM dental lab models- scan a stone
cast of prepared tooth in lab. Produce coping
and poreclain is then added.
 CAD/CAM for outsourcing- network
machining centre
6

 Fabrication of inlays, onlays, crowns,
 Fixed ,removable partial dental prostheses,
 Implant abutments,
 Substructure of removable and fixed implant-
supported prostheses
 Maxillofacial prostheses, and
 Complete denture

 Improper tray selection,
 need for disinfection of the impression,
 separation of impression material from the
impression tray,
 distortion of conventional
 impressions before pouring and
 storage of impressions for potential remaking of
casts and dies.

 Optical camera,
 LASER surface scanning device,
 three dimensional (3-D) scanning device (digitizer),
 photogrammetry,
 Moiré fringe displacement,
 computed tomography (CT-Scan),
 magnetic resonance imaging (MRI),
 3-D ultrasonography etc.
are some of the technologies used for computer surface
digitization

 Surface of stone models is measured by tools, called
digitizers and scanners, to obtain digital data that represents
morphology of target tooth.
 Laser beam with Position Sensing Device sensor
 Laser with CCD camera
 Intraoral digitizers
19

22
Designing of the restoration is done using
CAD software, which in turn send commands
to the CAM unit, for fabricating the
restoration.

Once the master model was scanned it was imported
directly into CAD software. the operator can start to
identify the insertion axis and block out undercuts.,
clearance from the gingiva can be dialed in to
accommodate acrylic thickness.
Following this the design process can really start in
earnest. A full suite of indirect and direct retainers,
major connectors and acrylic retention features can
be designed into the denture.
Using the Haptic arm can be a little alien at first but
soon becomes second nature and the user will be
quickly designing occlusal rests with intricate
reciprocal and retentive arms.
Acrylic retention can also be designed-in using a
variety of mesh options and surface modifications,
just as for a traditional RPD.
Haptic arm and DS20 dental scanner

Removable partial denture metal frameworks can be produced
directly from metal or alternatively a resin pattern framework can
be formed and then cast using conventional fabrication method

 CBCt & surgical stent
 Implant fixture
 Abutment
 superstructure

 Communication between implant surgeon and
restorative dentist
 CT imaging improves the success rates from a
restorative and surgical view.
 Used in critical anatomic situations and for placing
the implant in an ideal position in bone because it
eliminates possible manual placement errors and
matches planning to prosthetic requirements
 Communicates the actual implant position to the
surgical site esp. in fixed restoration to maximize
the precision of implant placement.
 By using a CAD/CAM surgical guide, a pre-
fabricated provisional restoration can be delivered
immediately after implant placement, which
increases the patients’ self-confidence
dramatically.

Digital Engineering of Bio-Adaptable Dental Implants. Gilbert et al,2011

Computer usage in implant placement has increased in the past decade.
Recently with the use of CAD/CAM application patient-specific abutments can
be fabricated. These CAD/CAM fabricated custom abutments are designed by
computer and manufactured by computer operated machines for obtaining
unsurpassed accuracy and precision. As they are milled from medical-grade
Titanium, they have superior biocompatibility and best possible integration
with implant fixture.
The CAD/CAM fabricated custom abutments carries advantages like: -
precision, milled from titanium, ideal coronal preparation, correct path of
insertion, perfect emergence profile, 6° angled implant axis, shaped like a
natural tooth and reduced chair time.
Computerized designing of abutment is done and primary abutment is
fabricated from commercially pure titanium via computerized-milling technique.
Another duplicate abutment is milled, which is functionally identical to
primary abutment, thus reducing chair time.

 The CAD component virtually designs the 3D contour of the final implant
component., the implant abutments and frameworks are produced by
CAM at a central production facility.
Ex: Procera (Nobel Biocare), Etkon (Straumann), CAMStructure (Biomet 3i), and
Atlantis (Astra Tech).
 Custom CAD/CAM abutments combine most of the advantages of stock
and cast custom abutments
 In addition to a predictable fit and durability, all the prosthesis parameters
are modifiable including the emergence profile, thickness, finish line
location, and external contour. This is performed by copying resin or wax
pattern manufactured by a dental technician or by computer software
modeling
 Initially, CAD/CAM was used to fabricate implant components from
titanium and titanium alloy. To date, CAD/CAM is the only way of
producing implant components from high-strength ceramics such as
densely sintered alumina and partially stabilized zirconia.

series of cross-sectional
slices layered on top of
one another.
Subtractive
manufacturing
Additive
manufacturing
power driven machine
tools as lathes, milling
machines, drill press.

Uses images from a digital file to create an object
by machining (cutting/milling) to physically
remove material and achieve the desired
geometry

The dental CNC machines are composed of multi-axis
milling devices to facilitate the 3D milling of dental work
pieces.
 the 3-axis milling systems : most commonly used, the
milling burs move in three axes according to
calculated path values.. rotation of the blank is
incorporated within the machine, allowing 3D milling
of the internal and external surfaces, and establishing
greater definition of the surface features
 the 4-axis machines: for milling long span frameworks.
 The 5-axis machines : facilitates production of very
complex geometries and smooth external surfaces,
suitable for producing complex shapes such as acrylic
denture bases

The CAD/CAM technique contains fewer production steps
compared to conventional techniques. The three main factors
affecting the fit are:
 precision of the scanner,
 how effectively software can transform the scanning data
into a 3D model in the computer and
 the precision of the milling machine.
Scanners have a precision of 20µm. During the CAD process of
the framework, drill compensation is activated routinely. Milling
burs require to be changed periodically as they are cutting hard
metal alloys like Co–Cr.

 Porcelain
 Ceramic blocks available as Zirconia
(fully sintered and partially sintered),
Zirconium Oxide
 Lithium disilicate glass blocks
 Glass infiltrated alumina
 Glass infiltrated alumina with partially
stabilized Zirconia
 Densely sintered high- purity Alumina
 Yttria-stabilized tetragonal Zirconia
polycrystal material
57

 eliminate waxing, investing, and casting of prostheses which is assumed to
improve the overall precision.
 Milling can reduce fabrication defects in dental prostheses, by relying more on
the tighter quality control processing of the material manufacturer rather than
commercial laboratory
 manufacturing deficiencies, such as porosities and inhomogeneous consistency,
are reduced
 Recently, highly dense ceramics (high flexural strength a, fracture toughness)
were introduced, zirconia can be used to fabricate dental prostheses such as
fixed dental prostheses, implant abutments and frameworks where a high
occlusal load is expected. To produce the zirconia workpiece, the material
should be heat treated to its melting temperature followed by strictly controlled
cooling to ensure the zirconia is composed predominantly from the tetragonal
phase . Such a set-up is not available in commercial dental laboratories.

Eliminates second visit No casting errors
Accuracy of impression and
restoration
No layering errors
Opportunity to view, adjust,
rescan
Cost effective
No physical impression for the
patient
Cross infection control
Saves time and labor No Temporization
View occlusion digitally Esthetic
59

60
Initial equipment cost
Capturing errors
Color- customization

Ex: CEREC in Lab system -
 The tooth preparation die is secured in the scanning
platform and data is captured with a non-contact laser.
 A Ceramic block (ingot) is placed in the milling
chamber. Two milling diamonds create the precise
restoration. Porcelain build-up is done which results in
an aesthetically pleasing restoration. Then the fit is
confirmed in the patient’s mouth and required
adjustments are done.

Implant abutments and frameworks are produced by milling
ex Procera (NobelBiocare), Etkon(Straumann), CAM structure
(Biomet 3i) and Atlantis ( astra tech)
Advantages
1. Custom CAD/CAM abutmants combines most of the
advantages of stock and cast custom abutments
2. perfect fit adaptability
3. All parameters are modifiable including the emergence
profile, thickness, finish line location , and external
contour

• Fabrication of cast partial dentures can be done using Co-Cr Alloys , pure
Ti and Ti-6Al-4V Alloy by utilizing CAD-CAM technologies.
• Machining process of prefabricated blocks of different materials;
• this process is not the most suitable for RPD preparation, since their
components present complex shapes and must be thin, it is difficult to
establish an appropriate attachment point with the milling machine, and
the components can suffer deflection during the process, as reported by
(Smith and Dvorak, 1988).

Most commonly available rapid prototyping machines use one of
the five techniques:
• Stereolithography (SLA)
• Laminated object manufacturing
• Selective laser sintering(SLS,SLM)
• Fused deposition modeling
• Solid ground curing 3D ink jet printing

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The additive systems used in dentistry are :
• stereolithography,
• selective laser sintering or melting, and
• 3D printing
it can :
-Fabricate preproduction pattern (wax or plastic) that can be
transformed to a definitive prosthesis, and
-it can directly produce definitive workpieces in metals, resins, or
ceramics

Create a CAD model of the design
# Object to be built is modelled using software
# Solid modelers like ProEyield better result
# Existing CAD file may be also used
Convert the CAD model to STL (standard Tessellation language format
# STL format is the standard of rapid prototyping industry
# This format represent 3 D surface as an assembly of planar triangles and
describes only surface geometry ( without any representation of color,
texture etc)
Slice STL file into thin cross-sectional layers
# Several programmers are available for this
# STL modals are sliced into a number of layers (0.01 to o.7 mm)
# Orientation size and location are adjusted using the software
Construct the model one layer a top another
# RP machine build one layer at a time from polymers, paper, or powdered
metal
# Fairly autonomous needing little human intervention
Clean and finish the model
# Post processing step
# Prototype may require minor cleaning and surface treatment

All share the following features :
 Incremental vertical object build up
 No material wastage
 Large objects produced
 Passive production (no force application)
 Fine details production

the process requires a liquid plastic resin (photopolymer) which is then
cured by an ultraviolet (UV) laser.

 Materials:
(wax, polystyrene, nylon, glass, ceramics, various metal alloys,
and even sugar), and a thickness of anything between 25-µm to
50-µm is achievable with excellent accuracy and good surface
finish.
 Prosthodontic application :
1. produce resin objects such as surgical templates for oral and
extraoral implant placement and preprosthetic surgery.
2. the fabrication of facial prosthesis patterns, occlusal splints
,burnout resin patterns, and investing flasks .
3. With the aid of multislice CT data, real size anatomical models
of patient can also be replicated to facilitate visualization of
bone anatomy. Further, these anatomical models can be used
to assist with the fabrication of customized implants for hard
tissue reconstruction.

 Use laser beam to selectively fuse powdered materials such
as(nylon, elastomer or metal) into solid object
 Parts are built in a platform which sits below the surface in a bin of
heat fusible powder Laser traces the pattern of first layer, sintering
it together
 Then platform is lowered , powder is reapplied and process is
repeated

Oxidation of the metal can be controlled by confining the melting to a
sealed gas chamber.
SLS fabrication of a pattern from ceramics or polymers while
SLM describe pattern fabrication from metal the material is fully melted
rather than sintered, allowing different properties (crystal structure,
porosity, and so on).
The only additive method that is available to produce metal workpieces
such as crowns, fixed dental prostheses, or removable partial denture
frameworks. Further, this technique can produce customized implants for
maxillofacial applications or joint replacement

Selective laser sintering process

 Marginal discrepancy is clinically acceptable with the restoration
possessing consistent quality and strength ,the ability to grow
multiple parts at one time, though the initial investment is high,
 They are very cost and time effective.
 A dental technician can produce at best 20 units/day using
conventional casting procedures used today whereas; use of fully
automated laser sintering technology can produce about 450 units of
high quality crowns and bridges in 24 h with an efficiency of 90 units
per run of the machine
 crown copings and bridge framework (90–120 units) for a job lot, laser starts
production layer by layer in a period of only a few hours.
 The machine produces several hundred dental prostheses out of metal powder.
The speed is approximately 3 min/crown. The metal powder is fused into a solid
part by melting it using the focused laser beam. Parts are built up additively layer
by layer, usually 20 um thick. This process allows for highly complex geometries
to be created directly from the 3D CAD data, fully automatically without any
tools, producing parts with higher accuracy and detailed resolution, good surface
quality and excellent mechanical properties.

• Object made using ink jet technology in three dimensions. These
printers work by layering powder a powder substrate and binding it with
pigmented glue.
• This is the only 3D printing technology capable of printing in full color.
• Extrudes material from a nozzle that solidifies as soon as it is deposited
on the manufacturing platform. The layer pattern is achieved through
horizontal nozzle movement and interrupted material low.
• This is followed by vertical movement for the sequential layer
deposition.

Materials:
• Thermoplastic materials, (waxes, resins, or fused
filament), which pass through a heated nozzle and
solidifies immediately after extrusion.
• liquid ceramic or resin materials with a binder can be
printed, following deposition, solidifies immediately .
• Glass, plastic, concrete, porcelain and living tissues and
cells
• Some systems also allow for multicolour production .
This approach is used in dentistry to fabricate dental models,
facial prosthesis patterns, acrylic prostheses, investing
flasks, and castable or ceramic frameworks.
3D printing is distinguished from other fabrication methods in
the ability to print multiple materials at one time

3D printing is touching many lives in many (but not limited to) sectors
mentioned below,
Auto Mobile
Robotics
Jewellery
Architecture
Defense
Fashion
Medical
Home Decoration
Others
Application of 3D printing

One of the most
expensive commercial
real estates, comprised of
20 iconic new buildings, is
scheduled to finish its first
phase in 2016 at Seoul .
Modelzium,
the architecture company
behind this, developed all
the building models using
Objet 3D Eden Printer.

At least half a dozen fellows
at University of Southampton led
by Andy Keane and Jim Scanla, test
flew this aircraft successfully. This
machine can fly for around 30
minutes at a speed of around 90
mph.
It is believed that 3D printing
will allow uncrewed aircraft known
as drones or UAVs to go from the
blue print to flight in a matter of
days. The world's first printed plane

Physically challenged people
could walk again with
customized artificial body
parts.

 Scientists are now able to use a 3D printing technique to produce
biodegradable ‘scaffolding’ for facial features and internal organs
Using the printouts, bioengineers are able to cultivate human skin
cells around the scaffolding to create living tissue
 The technique has already been used on patients for small body
parts such as blood vessels and it is hoped that facial features will
soon be available
 Experts are also hoping technique will make man-made organ
transplantation possible within the next two decades (Bioprinting).

Rapid prototypingMilling
No material wastage
Reusable for future processing
Material wastage 90%
ability to fabricate large workpieces
(facial prosthesis ,skeleton models)
More suitable for smaller
workpieces
fabrication of workpieces with different
consistencies and material properties
Single material ,consistency
no compensation is required , passive
production (no force application).
The accuracy of additive technique is
dependent on layer thickness and the
width of curing beam
Surface cracking, shrinkage
produce customized workpieces that fit
patient hard and/or soft tissues

Ortorp et al. showed that SLM produced Fixed dental prosthesis
frameworks with almost half the fit discrepancies (84 µm) of those
produced by milling (166 µm) attributed to the absence of a compensation
mechanism in the production process
The overall dimensional accuracy of SLM has been attributed to the lack of
force application and vibration of the machine during production of the
workpiece. This feature is of significant importance as it allows the
production of delicate and thin structures without causing deformation or
recoil of the components. For example, removable partial denture
framework components can only be produced by selective laser melting
Williams et al. also reported that the fit of RPD frameworks produced using
the additive manufacturing procedure is comparable to frameworks
produced using conventional methods
split mouth clinical study revealed that the stereolithography Surgical
guides allowed for implant placement closer to the planned position than
conventionally fabricated guides

 Methods of denture fabrication have not progressed
substantially for the 70 years since PMMA was introduced in
1936
 this process is complex and difficult for dentists, requires
experienced prosthodontists and dental technicians. In
addition, it requires many visits of the patient and a large
amount of laboratory work.
 Elderly patients in particular can find the necessity for a lot of
visits distressing.
 Furthermore, acrylic resins do not fulfill all of the
requirements for hypothetically ideal denture base materials.

Maeda et al, a group of Japanese investigators, are credited with
the first published scientific report on using computer-aided
technology to fabricate complete dentures.
Their report in 1994 described the fabrication of complete
dentures from photopolymerized composite resin material with
rapid prototyping technology.
This was followed by a report in 1997 from another Japanese group,
Kawahata et al, who explored the concept of digitally duplicating
existing dentures and milling them by using a CNC milling machine.
Since then, several investigators have contributed to improvements in
this field, ranging from digital tooth arrangement to incorporating
(CBCT) to scanning and fabricating complete dentures through
either rapid prototyping technology or CNC milling.

1. -the need for a min 4-5 pt visits and
additional postinsertion visits
2. high treatment costs due to
increased pt vists
3. varying lab. expenses and time
4. lack of intimate fit of the denture
base with underlying tissues due to
polymerization shrinkage
5. inability to easily create an optimal
duplicate denture
The ability to customize
tooth arrangement to
conform all preceding
steps before try in stage.

1. Reduced number of patient visits (old pt)
2. Superior strength and fit of the dentures due to use of prepolymerized
acrylic resin blocks for milling
3. Reduced cost for the for the pt and the clinician
4. Reduced potential for dentures to harbor microorganisms and minimize
resultant infections
5. Easily reproducible( duplicate denture) CAD files digitally stored
6. Improved potential for standardization in clinical research on CD as well
as implant-retained overdenture
7. Ability for better quality control

THE USE OF CAD/CAM has become available for CD through
the Avadent and Dentca systems. Avadent uses laser scanning
and computer technology. teeth are arranged and bases
formed using proprietory software. The bases are milled
from prepolymerized pucks of resin

Dentca uses computer software to produce virtual
maxillary and mandibular edentolous ridges.
Arrange the teeth and form bases, the dentures
are fabricated using a conventional processing
technique

 Clinicians can request a wax trial denture that has a
CAD/CAM milled base with the denture teeth set in wax so
they can be repositioned as needed. Or a tooth-colored
stereolithographic trial denture that can be modified by
reshaping the teeth or adding composite resin to guide in
fabrication of the definitive prosthesis
 This stereolithographic trial denture can also be used for
diagnostic purposes to determine if a fixed implant
prosthesis
 (fixed compleie denture) will provide adequate lip support
or the denture flange support provided by an overdenture is
needed. It can also be converted to a surgical template for
implant placement.

Kattadiyil & Nadim. CAD/CAM complete dentures : review of two
commercial fabrication systems. CDAJ, Vol 41,no 6 , 2013

 All reports from published literature and current commercial manufacturing
systems use a combination of manual and digital procedures for the clinical
and laboratory stages of computer-aided denture fabrication.
 This is because the impressions of edentulous arches are still made using
conventional techniques and materials. A complete digital impression of the
edentulous arches as performed for tooth preparations/implant abutments has
not yet been researched.
 This is challenging because digital impressions for edentulous arches
require registration with a dynamic movement of the muscles and jaws,
which may be difficult to execute with an intraoral 3D scanning type of
device. However this gap could be addressed by future research.
 Another manual step in the laboratory stage is bonding the artificial teeth
into the recesses of the denture base. Understanding the strength of this
bond or even eliminating this procedure by milling the denture in 1 piece with
the artificial teeth
 future research elements such as denture extensions, denture retention, lip
support, and OVD. Examples of true outcomes such as oral health-related
quality of life, prosthesis satisfaction, esthetic and functional satisfaction,
and comfort

CAD/CAM is widely used for the fabrication of maxillofacial
prostheses, extraoral radiation devices, etc.
The 3D surfaces imaging (using CAD software). This 3-D surface image
aids in fabrication of resin model with Lithographic wax pattern
is made computer assisted 3d imaging is done. Data is entered in
computer and prosthesis is milled by computer aided milling machine.
Thus, a silicone maxillofacial prosthesis is fabricated using CAD/CAM
technology.

1. with proper digital library, various shapes of nasal structure could be
superimposed on the digital model and the required one chosen in a
matter of few hours
2. For paired structures (eye,ear), duplication to the exact dimension
and mirroring can be done.
3. Using RP , complex internal forms as in (external ear) can be
reproduced with precision
4. Eliminate the need for an impression procedure
5. The digital model and the plastic prototype can be preserved.
(replacement required in few years following discoloration, change
in fit , tearing, aging general wear), allow multiple pouring for shade
matching purposes
6. Don’t require a skilled anaplastologist for sculpting the clay model of
the defect area
7. The possibility of 3 d visualization and easy virtual changes ( type of
nose, dimensions , position on face, ensure optimization of the
whole process before manufacturing ,allow feed back of the pt to be

First a 3D scanner will scan the normal ear of the patient. At this
point, the scan will be inverted, and turned into a 3D printable
model. The researchers will then 3D print the ear out of a spongy
plastic-like material which is porous and will act as a scaffold. The
ear will then be placed under the skin on the forearm of the
patient for between 4
with the necessary blood
vessels.

 South African doctors implanted two 3D printed titanium lower jaws for two patients
 It is only the second time in the world that such an operation has taken place. The first
operation was carried out in June, 2011 in the Netherlands on a 83-year old woman with
a serious jaw infection. The implant was made out of titanium powder.
 The jaw bones were printed , costs from ($11,455) for patients...
 patients will definitively be able to eat and to speak. Facial control will be relatively
normal. The only thing is that we won’t be able to replace their teeth at that stage. We
are not there yet.”
 The patients will regain at least 60% of their jaw function while also saving their facial
features. Doctors will now be monitoring the patents closely to prevent any infections.
 Before the advent of 3D printers, medical parts would be made using computer
numerical control (CNC) milling, which wasted up to 80% of the titanium block. In
contrast, 3D printing melts every grain of the titanium powder.

A team of medical professionals successfully performed a jaw transplant using a 3D-printed,
patient-specific prosthesis made out of titanium powder.

• Tamrakar AK, et al. CAD/CAM IN PROSTHODONTICS - A FUTURISTIC OVERVIEW . Annals of Dental
Specialty Vol. 2; Issue 1. Jan – Mar 2014
• Sun and Zhang. . Rapid Prototyping in Prosthodontics Journal of Prosthodontics 21(2012) 641 644
• INOKOSHI, KANAZAWA ,MINAKUCHI. Evaluation of a complete denture trial method applying rapid
prototyping. Dental Materials Journal 2012; 31(1): 40–46. g .
• Lee Ventola. Medical Applications for 3DPrinting: Current and Projected Uses. CVol.39. No.10 October2014
• . MIYAZAKI et al. A review of dental CAD/CAM: current status and future perspectives from 20 years of
experience, Dent al Mateials Journal 2009; 28 (1): 4 4－56
• Lima et al,2009 Removable Partial Dentures: Use of Rapid Prototyping journal of Prosthodontics 00(2014) 1–4 C
• KATTADIYIL et al.CAD/CAM Complete Dentures: A Review of Two Commercial Fabrication System
JOURNALvoL 41, No6
• Avinash S. Bidra Computer-aided technology for fabricating complete dentures: Systematic review of historical
background, current status, and future perspectives. J Prosthet Dent 2013;109:361-366
• Bhambhani et al. REVIEW ARTICLE. Digitization and Its Futuristic Approach in Prosthodontics. J Indian
Prosthodont Soc (July-Sept 2013) 13(3):165–174
• Aeran et al. Computer Aided Designing-Computer Aided Milling in Prosthodontics: A Promising Technology for
Future IJSS Case Reports & Reviews | May-June 2014 | Vol 1 | Issue 1
• CAD/CAM technology: application to complete dentures. Loma Linda University Dentistry Volume 23, Number
2 2012 Review Article
• Abduo, et al. Trends in Computer-Aided Manufacturing in Prosthodontics: A Review of the Available Streams
2nternational Journal of Dentistry. Volume 2014,

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CAD/CAM in prosthetic dentistry

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