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For 20 years, exciting new developments in dental materials and computer technology have led to the success of contemporary dental computer-aided design/computer-aided manufacturing (CAD/CAM) technology.
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Biotechnology & Biotechnological Equipment
ISSN: 1310-2818 (Print) 1314-3530 (Online) Journal homepage:
An Overview of Dental CAD/CAM Systems
G. Uzun
To cite this article: G. Uzun (2008) An Overview of Dental CAD/CAM Systems, Biotechnology &
Biotechnological Equipment, 22:1, 530-535, DOI: 10.1080/13102818.2008.10817506
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© 2008 Taylor and Francis Group, LLC
Published online: 15 Apr 2014.
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Keywords: CAD/CAM, scanning software, dental materials,
future trends
Computer-aided design (CAD) and computer-aided
manufacturing (CAM) technology systems use computers to
collect information, design, and manufacture a wide range
of products. With CAD/CAM, parts and components can
be designed and machined with precision using a computer
with integrated software linked to a milling device. This
technology was introduced to dental community in the early
1980s. The earliest attempt to apply CAD/CAM technology to
dentistry began in the 1970s with Bruce Altschuler, Francois
Duret, Werner Mormann, and Marco Brandestini. Young
and Altschuler (51) rst introduced the idea of using optical
instrumentation to develop an intraoral grid surface mapping
system in 1977. The rst commercially available dental
CAD/CAM system was CEREC, developed by Mormann and
Brandestini (25).
A dental restoration must t its abutment within a 50 μm
range (12). This requirement calls for the system to have a very
accurate data collection technique, suf cient computing power
to process and design complex restorations, and a very precise
milling system.
During the last 2 decades, exciting new developments
have led to the success of contemporary dental CAD/CAM
technology. Several methods have been used to collect 3-
dimensional data of the prepared tooth using optical cameras,
contact digitization, and laser scanning. Replacement of
conventional milling discs with a variety of diamond burs has
resulted in major improvements in milling technology.
The hope and expectation was that automation could
achieve the following:
- to produce higher- and more uniform-quality material by
using commercially formed blocks of material;
- to standardize restoration-shaping processes;
- to reduce production costs.
The use of high-strength structural materials like alumina-
and zirconia-based ceramics for restoration cores and
frameworks, which can be shaped only by CAD/CAM systems,
has both increased the lifetime of restorations and expanded
the demand for CAD/CAM-produced restorations (16). As a
result, the number of CAD/CAM systems currently available
to the dental community has increased substantially within the
last few years (14, 39, 49).
All CAD/CAM systems have three functional components:
data capture or scanning to capture and record data about
the oral environment (tooth preparation, adjacent teeth and
occluding tooth geometry); CAD to design the restoration to
t the preparation and to perform according to conventional
dental requirements; and CAM to fabricate the restoration.
Data Capture
Data capture differs remarkably between commercially
available dental CAD/CAM systems (49). An intraoral digital
3-D scanning device (digitizer) is an integral component of the
CEREC system (CEREC 3D, Sirona Dental Systems GmbH,
Bensheim, Germany). The Evolution 4D system, currently
under development by D4D Technologies (Richardson, Texas),
also is expected to have intraoral data capture capabilities.
Other commercially available CAD/CAM systems capture
data from models, using mechanical or optical digitizers of
various types. With few exceptions, these high-precision
digitizers use technologies that prevent them from being used
intraorally. Mechanical digitizers, for instance, must map the
entire surface of a prepared tooth while accurately maintaining
the relative position of the device to the tooth. Many optical
digitizers are exceptionally sensitive to any motion. Slight
movement of a patient during data acquisition with either of
these types of scanner would compromise the quality of the
data, ultimately leading to a restoration that would not t. In
most cases, the scanner used to capture data is an integral part
of the CAD/CAM system and operates only in combination
with dedicated CAD software.
G. Uzun
Hacettepe University, School of Dental Technology, Sıhhıye, Ankara, Turkey
Correspondence to: Gülay Uzun
For 20 years, exciting new developments in dental materials and computer technology have led to the success of contemporary
dental computer-aided design /computer-aided manufacturing (CAD/CAM) technology.
This article provides an overview of the status of current CAD/CAM systems, describes components of CAD/CAM technologies
and suggests future possibilities.
Restoration Design
Several CAD software programs are available commercially
for designing virtual 3-D dental restorations on a computer
screen. Some of these programs can design restorations nearly
matching the excellence of restorations produced by master
dental technicians. The degree of interaction needed from the
CAD/CAM system operator to design a restoration varies,
ranging from substantial to no required user operations. Even
in the most automated systems, the user generally has the
option to modify the automatically designed restoration to t
his or her preferences. Like the data acquisition systems, the
software programs usually are proprietary to the CAD/CAM
system and can not be interchanged among systems. When
the design of the restoration is complete, the CAD software
transforms the virtual model into a speci c set of commands.
These, in turn, drive the CAM unit, which fabricates the
designed restoration.
Restoration Fabrication
CAM uses computer-generated paths to shape a part. A diverse
set of technologies has been used to create dental restorations.
Early systems relied almost exclusively on cutting the
restoration from a prefabricated block with the use of burs,
diamonds or diamond disks (44). This approach, in which
material is removed to create the desired shape, is termed a
“subtractive method”; material is subtracted from a block to
leave the desired shaped part (the restoration) (13). Subtractive
fabrication can create complete shapes effectively, but at the
expense of material being wasted. Approximately 90 percent
of a prefabricated block is removed to create a typical dental
restoration. As an alternative, “additive” CAM approaches like
those used in rapid prototyping (also called “solid free-form
fabrication”) technologies are beginning to be used in dental
CAD/CAM systems (26). Selective laser sintering is one of
the technologies that can be used to fabricate either ceramic or
metal restorations (Medifacturing, Bego Medical AG, Bremen,
Germany; Hint ELs, Hint-ELs, Griesheim, Germany). In this
method, the computer design of the part (the dental restoration)
generates a path much like a cutting tool path in existing CAD/
CAM systems. However, instead of cutting, the system sinters
material along the path, 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. Some
commercially available CAD/CAM systems use a combination
of additive and subtractive CAM approaches. In one (Procera,
Nobel Biocare, Göteburg, Sweden), an enlarged metal die rst
is milled based on the 3-D data for the prepared tooth with
the use of the subtractive approach. (This enlargement takes
into account shrinkage associated with sintering the nal
restoration to achieve its nal strength.) Powder is compacted
under pressure onto the metal die, creating an oversized block
by means of an additive approach; the block then is milled away
to create the outer contours of the restoration. The oversized
restoration is removed from the die and sintered to make the
material as dense as possible and to shrink it to its correct
size. Another combined CAM approach (Wol-Ceram, Wol-
Dent, Ludwigshafen, Germany) involves the path, 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. Another combined CAM approach
(Wol-Ceram, Wol-Dent, Ludwigshafen, Germany) involves
the application of a slurry of alumina powder directly to
a master die using an additive electrophoretic dispersion
method, which creates a coping. The operator trims away by
hand excess material extending beyond the margin. The outer
contour of the restoration is shaped using a subtractive CAM
approach. The operator then removes the coping from the die
and in ltrates glass. An additive approach also has been used
to generate copings and frameworks for bridges from pure
alumina oxide and zirconia-based ceramics with super ne
nanodispered ceramic particles smaller than 100 nanometers
(ce.inovation, Inocermic, Hermsdorf, Germany). This system
is housed in a production center, and details of the fabrication
have not been disclosed. Brick and colleagues (6) reported that
it produces frameworks with high strength. A different additive
rapid prototyping technique, 3-D printing, is being used to
design and then print a wax pattern of a restoration (WaxPro
printer of the Pro 50 system, Cynovad, Saint- Laurent, Quebec,
Canada) (45). Operating like an inkjet printer, the machine
builds wax patterns of frameworks and full crowns. The wax
pattern subsequently is cast or pressed in the same manner as
manually waxed restorations would be. An advanced printing
unit (Cynovad) prints a resin-type material instead of the wax.
This system has an expanded capability beyond that of most
CAD/CAM systems for dental restorations; it also can be used
to fabricate auricular prostheses (37).
Integration of these technologies has resulted in the
introduction of several highly sophisticated CAD/CAM
systems: CEREC3 and in lab DCS Precident; Procera; Lava;
Cercon Smart C e r a m i c s ; Everest; Denzir; DentaCad;
and Evolution D4D. CAD/CAM technology provides several
advantages from the dental laboratory perspective. CAD/
CAM systems offer automation of fabrication procedures with
increased quality in a shorter period of time. Dental CAD/
CAM systems have the potential to minimize inaccuracies in
technique and reduce hazards of infectious cross-contamination
associated with conventional multistage fabrication of indirect
restorations. However, capital costs of these CAD/CAM
systems are quite high and rapid large-scale production of good
quality restorations is necessary to achieve nancial viability.
CAD/CAM systems have been created for dental
applications other than producing restorations. One system
(SL, Perfactory, Envisiontec GmbH, Gladbeck, Germany)
uses stereolithography, another additive process to produce
3-D dental components from acrylics (48). Three-dimensional
occlusal splints and similar components are created by
selectively light-curing sequential layers of acrylic monomer in
a liquid. In addition, CAD/CAM systems have been developed
to fabricate surgical templates (custom drill guides) to guide
dental implant placement (31) (SurgiGuide, Materialise,
Leuven, Belgium) and working models, permiting restorations
to be inserted immediately after implants have been placed (41)
(Nobel Guide software, Nobel Biocare). Both systems use data
captured from computerized tomographic scans in conjunction
with CAD software to determine the most ideal restoration
placement, and CAM Technologies generate the templates and
working models.
Restorative Materials for CAD/CAM
Using CAD/CAM systems, operators can fabricate restorations
from an array of materials. These include ceramics, metal alloys
and various composites. The ceramics currently being used
for restorations are predominantly alumina- (including those
subsequently in ltrated with glass), zirconia- and porcelain-
based ceramics. The combination of materials that can be used
and restoration types that can be produced by different systems
CAD/CAM systems based on machining of presintered
alumina or zirconia blocks in combination with specially
designed veneer ceramics satisfy the demand for all-ceramic
posterior crowns and xed partial dentures. Many ceramic
materials are available for use as CAD/CAM restorations (Table
1). Common ceramic materials used in earlier dental CAD/
CAM restorations have been machinable glass ceramics such
as Dicor (Dentsply Caulk, Milford, DE 19963) or Vita Mark
II (Vident, Bera, CA 92821). Although monochromatic, these
ceramic materials offer excellent esthetics, biocompatibility,
great color stability, low thermal conductivity, and excellent
wear resistance (24). They have been successfully used as
inlays (28, 33), onlays (28), veneers (21), and crowns (3).
However, Dicor and Vita Mark II are not strong enough to
sustain occlusal loading when used for posterior crowns (19).
For this reason, alumina and zirconia materials are now being
widely used as dental restorative materials. These ceramic
agents may not be cost-effective without the aid of CAD/CAM
technology. For instance, In-Ceram l, rst described by Sadoun
and Degrange (30), has been shown to have good exural
strength and good clinical performance (29, 32). However, the
manufacture of conventional In-Ceram restoration takes up to
14 hours (15). By milling copings from presintered alumina
or zirconia blocks within a 20 minute period and reducing the
glass in ltration time from 4 hours to 40 minutes, Cerec inLab
decreases fabrication time by 90%. Zirconia is strong and has
high biocompatibility. Fully sintered zirconia materials can be
dif cult to mill, taking 3 hours for a single unit. Compared with
fully sintered zirconia, milling restorations from presintered
or partially sintered solid blocks is easier and less time-
consuming, creates less tool loading and wear, and provides
higher precision. After milling, In-Ceram spinell, alumina, and
zirconia blocks are glass in ltrated to ll ne porosities. Other
machinable presintered ceramic materials are sintered to full
density, eliminating the need for extensive use of diamond tools.
Under stress the stable tetragonal phase may be transformed to
the monoclinic phase with a 3% to 4% volume increase. This
dimensional change creates compressive stresses that inhibit
crack propagation. This phenomenon, called “transformation
toughening”, actively opposes cracking and gives zirconia its
reputation as the “smart ceramic.” The quality of transformation
toughness and its affect on other properties is unknown.
Zirconia copings are laminated with low fusing porcelain to
provide esthetics and to reduce wear of the opposing dentition.
If the abutment lacks adequate reduction the restoration may
look opaque. Because they normally are not etchable or
bondable, abutments require good retention and resistance
form. Alumina and zirconia restorations may be cemented with
either conventional methods or adhesive bonding techniques.
Conventional conditioning required by leucite ceramics (eg,
hydro uoric acid etch) is not needed. Microetching with Al2O3
particles on cementation surfaces removes contamination and
promotes retention for pure aluminum oxide ceramic (1). Two
in vitro studies recommended that a resin composite containing
an adhesive phosphate monomer in combination with a silane
coupling/bonding agent can achieve superior long-term shear
bond strength to the intaglio surface of Procera AllCeram and
Procera AllZirkon restorations (4, 5).
Common Restorative Materials for Dental CAD/CAM Systems
Restorative material CAD/CAM system Indications Cementation
Dicor MCG Cerec Inlay, onlay veneer Adhesive (dual-cured)
Vita Mark II Cerec Inlay, onlay veneer, anterior crown Adhesive (dual-cured)
Pro CAD Cerec Inlay, onlay veneer, anterior crown Adhesive (dual-cured)
In-Ceram Spinell Cerec 3D, Cerec inLab Anterior crown Adhesive (self-cured),
In-Ceram Alumina Cerec 3D, Cerec inLab, DCS
Precident Crown and anterior bridge Adhesive (self-cured),
In-Ceram Zirconia Cerec 3D Cerec inLab, DCS
Precident Crown and bridge Adhesive (self-cured),
Alumina Procera Crown and bridge Adhesive (self-cured),
Partially sintered Zir-
DCS Precident, Lava, Procera,
Everest, Cercon Crown and bridge Adhesive (self-cured),
Fully sintered Zirconia DCS Precident, Everest Crown and bridge Adhesive (self-cured),
CAD/CAM systems also can be applied to restorations
requiring metal and are used to fabricate implant abutments
and implant-retained overdenture bars. The DCS system can
fabricate crown copings from titanium alloy with excellent
precision (2).
Several articles have reported the extension of CAD/CAM
technology to the fabrication of maxillofacial prostheses such
as the arti cial ear (7, 18, 40, 42).
Review of Common CAD/CAM Systems
CAD/CAM systems may be categorized as either in-of ce or
laboratory systems. Among all dental CAD/CAM systems,
Cerec is the only manufacturer that provides both in-of ce and
laboratory modalities. Similar to Cerec is the Evolution D4D.
Laboratory CAD/CAM systems have increased signi cantly
during the last 10 years and include DCS Precident, Procera,
Cerec inLab, and Lava. Cercon is a laboratory system that
possesses only CAM capabilities without the design stage.
Business Models For Producing CAD/CAM Restorations
As might be expected, based on the number of CAD/CAM
systems available and the broad range in size and cost, different
business models for producing CAD/CAM restorations have
emerged. These include in-of ce systems, dental laboratory
systems, dental laboratories working in collaboration with a
production center, and a network or open-concept business
In-of ce system model. The rst, and so far only,
commercially available in-of ce system is the Cerec system
(Sirona). With this system, all three steps involved in the
automated production of restorations can be accomplished
in a dental of ce. The dentist can prepare a tooth and, by
selecting appropriate materials, can fabricate a restoration and
seat it within a single appointment. The supplement to this
issue of JADA summarizes the evolution of this system and
the performance of restorations produced by it as it reaches its
20th anniversary.
Dental laboratory. The dental laboratory model is similar
to that used in producing conventional restorations. The dental
of ce sends an impression or model of the prepared and
opposing teeth to the laboratory, and the laboratory fabricates
the restoration. The only difference with this CAD/CAM
technology is that at least part of the fabrication is automated.
Unfortunately, the cost of many of these CAD/CAM systems is
high, often precluding all but a few of the largest laboratories
from offering this service.
Dental laboratory–production center model. In the dental
laboratory–production center model, the dental laboratory
has the data acquisition and design software available to
it (36). The laboratory technician scans models and designs
the restorations, making optimal use of his or her skills. The
laboratory sends the nished design to a production center,
where it is converted into appropriate commands to drive
the CAM component of a CAD/CAM system. This model
minimizes the cost to the laboratory and has the potential to
improve fabrication ef ciencies.
Network or open-concept model. The network or open-
concept model is similar to the dental laboratory–production
center model, but in this model multiple commercial
laboratories and/or production centers collaborate. The dental
laboratories have data acquisition and design capabilities
and the production center and/or other dental laboratories
have the CAM capabilities. In general, only limited types
of materials can be fabricated with any one CAM system.
With this network model, greater exibility with regard to
material choices is possible; the same restoration design can be
produced from a broader array of materials. In the most open
concept, a standard le format (similar to that used in solid
free-form fabrication) facilitates transfer of design data to any
number of different CAM systems, permitting interesting and
more exible material choices and pricing strategies. Only a
few manufacturers of digitizers and software programs offer
networking or openconcept possibilities. Most dental CAD/
CAM systems operate as closed-data systems. That is, all
components are linked by a unique data format, precluding
data from one system from being used to shape a restoration
with a different system (46, 47). The notable exceptions are
the ZENO Tec (Wieland Dental+Technik GmbH, Pforzheim,
Germany) and Hint ELs (Hint-ELs) systems.
CAD/CAM Systems of the Future
No automated system currently offers the exibility with
regard to restoration types and material choices that is possible
with traditional fabrication methods. However, new and
emerging technologies will continue to push the boundaries
we face today. An emphasis on intraoral data acquisition
scanners and digitizers is likely. This could lead ultimately
to the elimination of impressions and stone models. It is
likely that future digitizers or scanners will be more robust,
facilitating accurate data capture despite the differences in
foundation restorations within teeth, as well as differences in
saliva and soft tissue. This means that data pertaining to the
prepared, adjacent and opposing teeth could be sent directly to
a CAD/CAM system without being interpreted by a technician
or clinician. CAD software is relatively mature and probably
will not change dramatically. However, likely enhancements
may include a simpler user interface and integration of virtual
articulators, which would facilitate automatic design of the
occlusal surface.
The CAM component of dental CAD/CAM systems likely
will undergo the most remarkable changes. A major challenge
that has not been addressed completely in existing systems is the
completely automated, economical, high-precision production
of restorations. Highspeed machining is being adapted,
permitting faster removal of material. This reduces machining
time and could reduce production costs. Femtosecond lasers
have been introduced for cutting dental materials, including
zirconiabased ceramics (43). Direct shell production uses a
rapid prototyping process similar to selective laser sintering
to create ceramic investments in the shape needed, without a
wax pattern (50).
Other systems may shape parts using additive techniques
such as selective laser sintering, stereolithography and 3-
D printing, as described above. Another rapid prototyping
approach that has shown much promise is direct-write
assembly (34). With this system, the material from which
the part is made is incorporated into special inks. The ink is
delivered through specialized nozzles along the “tool path,”
de ning the designed restoration to create the complex 3-D
part. As the ink leaves the nozzle, it freezes instantaneously
into the desired shape; however, for high-strength parts such as
ceramic dental restorations, the materials need to be made more
dense. This technology could expand the breadth of material
choices, eliminate damage induced during subtractive shaping
operations and minimize the amount of material needed to
produce a restoration.
One limitation of current CAD/CAM systems is their
inability to incorporate esthetic veneers with strong (but
relatively unesthetic) cores and frameworks. Lasers have been
shown to sinter translucent veneering silicate ceramics after
they have been applied to a core using a plotter system and
direct shell production casting (50). Other approaches such as
direct-write assembly also may be able to improve esthetics by
applying an esthetic outer layer onto a strong core layer within
a single additive CAM process. Many new technologies are
being applied in industrial elds, resulting in the creation of
complex 3-D parts from an array of materials. In the future,
practical application of these technologies to dentistry may
provide unexpected paradigm shifts in fabrication approaches
and materials options.
As more scanning and fabrication technologies are
introduced to fabricate restorations, it is likely that more
cooperative networks and open systems will be used (47).
People with special expertise may be required to select and
combine the components of open CAD/CAM systems.
Informed decisions will be needed to optimize the choice of
materials, hardware for shaping the materials and speci c
dental indications.
Marginal Integrity of CAD/CAM Restorations
One of the most important criteria in evaluating xed
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 (20). O’Neal and colleagues (27) reported the possibility
of wear resulting from contact of food particles with cement
when gap dimension exceeded 100 μm. Essig and colleagues
(11) conducted a 5-year evaluation of gap wear and reported
that vertical wear is half of the horizontal gap. The wear of
the gap increased dramatically in the rst year, becoming
stable after the second year. McLean and Von Fraunhofer (23)
proposed that an acceptable marginal discrepancy for full
coverage restorations should be less than 120 μm. Christensen
(9) suggested a clinical goal of 25 μm to 40 μm for the
marginal adaptation of cemented restorations. However, most
clinicians agree that the marginal gap should be no greater than
50 μm to 100 μm (8, 17, 35). 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 (10, 22, 38).
CAD/CAM systems have 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. Existing CAD/CAM
systems vary dramatically in their capabilities, each bringing
distinct advantages, as well as limitations. None can yet acquire
data directly in the mouth and produce the full spectrum of
restoration types (with the breadth of material choices) that can
be created with traditional techniques. Emerging technologies
may expand the capabilities of future systems, but they also
may require a different type of training to use them to their full
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... [5,11]. IPS Empress CAD (IvoclarVivadent), released in 2006, is a feldspathic glass made up of 35-45% leucite crystals with a particle size between 1 and 5 microns, embedded in a glassy matrix [12]. This material appears in the shape of blocks for lab-or chairside-fabricated ceramic restorations. ...
... This material appears in the shape of blocks for lab-or chairside-fabricated ceramic restorations. Given the increased density and homogeneity of the crystals in the glassy matrix, the blocks have a flexural strength of 160 MPa, which is still deemed insufficient when faced with high masticatory forces in the posterior region [11,12]. ...
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(1) Background: The study aimed to investigate compressive strength for three computer-aided design/computer-aided manufacturing (CAD/CAM) dental materials: glassceramic IPS Empress CAD (IvoclarVivadent), hybrid ceramic Cerasmart (GC) and polymer-reinforced graphene G-CAM (Graphenano Dental). (2) Methods: 45 samples consisted of the molar crowns fabricated by three CAD/CAM materials were cemented adhesively on 3D printed abutments (Asiga DentalResin). The samples were divided into 3 groups (n=15) according to the crowns thickness; group 1 under the cusps/cervical margins - 0.6 mm/0.4 mm, group 2 - 1 mm/0.7 mm respectively, and group 3 - 1.5 mm/1 mm. Additionally, 20 cylindrical specimens fabricated by the three crowns and abutments material (n=5) were prepared by CAD/CAM technique. All samples and specimens were subjected to an axial compressive load by using a universal testing machine (Instron 3366-10kN, USA) until fracture. (3) Results: The compressive strength were for Empress CAD 1258 MPa, Cerasmart 501.3 MPa, G-CAM 435 MPa and Asiga resin 360 MPa. G-CAM crowns exhibited a higher maximum compressive load (1701.5-2011.8N) than both Cerasmart (1295.4-1642.9N) and Empress CAD (494.3-597.5N). (4) Conclusions: The CAD/CAM crown materials presented different mechanical behavior; Empress CAD and Cerasmart presented a fragile behavior, with a high compressive strength when compared to G-CAM and Asiga resins.
... CAD/CAM systems have many applications in prosthodontics and restorative dentistry. These systems are usually composed of hardware and software that work together through the three major steps of the restoration fabrication workflow [5]. After acquiring physical geometries and their spatial position data, these data are transformed into digital images by using different types of scanners with their associated data analysis software. ...
... Finally, the design is accepted. The design data are imported into the CAM software to nest the restoration in the block or disc of material and then control the manufacturing strategy of the connected computer numerical control (CNC) dental milling machine to mill the intended restoration [5,6]. ...
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Objectives The purpose of this in vitro study was to assess and compare the marginal and internal fit of machine-milled crowns designed using three different CAD software programs.Materials and methodsDigital impressions of the master zirconia casts containing the prepared molar were obtained using an intraoral scanner. The obtained standard tessellation language (STL) files were imported into three CAD software programs (Multi-CAD, Blue-Sky CAD, and InLab), and crown designs were generated. Crown design digital STL files were used to mill crowns with a five-axis dental milling machine. The internal and marginal fits of the fabricated crowns over the master-prepared tooth were assessed using the triple-scan protocol and digital analysis techniques. The 3D marginal and internal fit values of the fabricated crowns from the designs generated by the three CAD programs were evaluated and statistically compared using one-way analysis of variance (ANOVA) and post hoc Tukey’s tests (α = 0.05).ResultsThere were no significant differences in the internal fit of the crowns designed by the three CAD programs (p > 0.05). However, there were significant differences in the mean marginal fit (p = 0.009) of the crowns. The marginal fit values for the InLab-designed crowns were significantly better than those for Multi-CAD (p = 0.03) and Blue-Sky CAD (p = 0.012) groups.Conclusions All three CAD programs can design clinically acceptable crowns in terms of internal and marginal fit. InLab crowns outperformed the Multi-CAD and Blue-Sky CAD programs in terms of marginal fit.Clinical relevanceIt is critical to test the ability of newly released CAD programs to design acceptable virtual crowns that can be transformed into actual crowns with optimal marginal and internal fit to existing clinical tooth preparations/conditions to ensure the high technical quality and long-term success of fabricated crowns.
... A new indirect method that uses computer-aided design/ computer-aided manufacturing technologies (CAD/CAM) as an alternative to the conventional direct method could potentially result in a faster laboratory procedure, increasing productivity, and providing consistently high-quality products, as opposed to the conventional direct method (Al-Humood et al., 2023;Fasbinder, 2010;Jain et al., 2022). In CAD/CAM dental systems, methods used in fabricating dental restorations can be categorized as subtractive manufacturing (SM) or additive manufacturing (AM) (Cortina et al., 2018;Uzun, 2008). ...
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Objective: The aim of this in vitro study was to compare the effect of printing layer thickness on the marginal and internal fit of interim crowns. Material and methods: A maxillary first molar model was prepared for ceramic restoration. Thirty-six crowns were printed with three different layer thicknesses using a digital light processing-based three-dimensional printer (25, 50, and 100 µm [LT 25, LT 50, and LT 100]). The marginal and internal gaps of the crowns were measured with replica technique. An analysis of variance was conducted to determine if there were significant differences between the groups (ɑ = .05). Results: The marginal gap of LT 100 group was significantly higher than that LT 25 (p = .002) and LT 50 groups (p ≤ .001). The LT 25 group has significantly larger axial gaps than LT 50 group (p = .013); however, there were no statistically significant differences between other groups. The LT 50 group showed the smallest axio-occlusal gap. The mean occlusal gap differed significantly by printing layer thickness (p ≤ .001), with the largest gap occurring for LT 100. Conclusions: Provisional crowns printed with 50 µm layer thickness provided the best marginal and internal fit. Clinical significance: It is recommended that provisional crowns be printed with a 50 µm layer thickness to ensure optimal marginal and internal fit.
... Today, CAD/CAM dentistry, which can produce provisional crowns, is one of the most successful of laboratory technologies [4]. However, bonding of orthodontic brackets to provisional crowns is a challenge. ...
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Background: The aim of this study was to find the best surface treatment for CAD/CAM provisional crowns allowing the optimal bond strength of metal brackets. Methods: The sample consists of 30 lower bicuspids and 180 provisional crowns. The provisional crowns were randomly divided into six different groups. Orthophosphoric acid etching (37%) was applied to 30 lower bicuspids. The provisional crowns had undergone different surface treatments. Group 1: No treatment (Control Group). Group 2: Diamond bur. Group 3: Sandblasting. Group 4: Plastic Conditioner. Group 5: Diamond bur and Plastic Conditioner. Group 6: Sandblasting and Plastic Conditioner. The brackets in all groups were identically placed using Transbond XT® Primer and Transbond XT® Paste. Then, the entire sample underwent an artificial aging procedure, and a measurement of the bond strength was conducted. After debonding, the surface of the crowns was examined to determine the quantity of the adhesive remnant. Results: Bonding to natural crowns recorded the highest average, followed by the averages of groups 5 and 6. However, group 1 recorded the lowest average. Groups 2 and 4 had very close averages, as well as groups 5 and 6. A statistically significant difference between the averages of all groups was recorded (p < 0.001) except for groups 2 and 4 (p = 0.965) on the one hand, and groups 5 and 6 (p = 0.941) on the other hand. Discussion: The bonding of brackets on provisional crowns is considered a delicate clinical procedure. In fact, unlike natural crowns, the orthophosphoric acid usually used does not have any effect on the surface of provisional crowns. Conclusions: Using a diamond bur combined with the plastic conditioner and sandblasting combined with that same product resulted in a bond strength close to natural crown.
... 37 All CAD/CAM systems have three functional parts: data collection or scanning to gather and store information about the oral environment, CAD for data manipulation and designing and CAM for fabrication. Digital workflow involved in the fabrication process using CAD/CAM system is described below: 38 Data capturing involves usage of intra oral digital 3-D scanning device. Data from models can also be gathered using mechanical or optical digitizers of various types. ...
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Although the idea of a digital workflow is not new in dentistry, it has just recently started to be applied in pediatric dentistry. Fabrication of space maintainer is a time-consuming procedure that needs constant communication with the laboratory to be receive and provide patients the best outcomes. These devices maintain space created by premature tooth loss so that the erupting permanent teeth will not experience any kind of malocclusion As a result of clinician's natural curiosity 3-D printed space maintainer have been developed. The advanced CAD/CAM technology used for fabricating digital space maintainers improves patient experience and compliance. The current paper provides an insight on available conventional space maintainers and various aspects of technologically advanced digitainers.
... In most situations, the scanner used to capture data is an inherent element of the CAD/CAM system and can only be utilised in conjunction with customised software. 3 The second stage of the digital workflow is data processing/planning. Processing/planning software is mainly used for analysis and diagnostics, treatment planning, or CAD. ...
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Objective: Computer-aided design (CAD) and computer-aided manufacturing (CAM) technology in dentistry has become noticeably more significant in recent years. The further development of CAD/CAM systems has led to a broader range of applications, more user-friendly operation, and improved accessibility. The present online survey aimed to investigate CAD/CAM technology utilisation amongst Austrian dentists as the first social media pilot study from Europe on this specific topic. Materials and methods: For this purpose, an online survey consisting of 27 questions was created using Google Forms. The questions were divided into 3 sections: general inquiries, questions for CAD/CAM users, and questions for nonusers. The questionnaire was randomly distributed to Austrian dentists via email and social media. A total of 115 responses were submitted. Results: The vast majority of respondents, 52.6% (n = 60), practised as general dentists. Furthermore, a significant proportion of participants specialised in oral surgery, 17.5% (n = 20), and orthodontics, 12.3% (n = 14). Approximately half of the respondents, 51.8% (n = 59), reported having a CAD/CAM device at their current workplace. Amongst the CAD/CAM users, 70.7% (n = 58) believed that CAD/CAM is important in increasing the number of patients visiting the dental practice. In total, 54.2% (n = 26) of nonusers indicated the high initial cost of purchasing a CAD/CAM device as the main reason for not utilising this technology. Conclusions: CAD/CAM technology appears to have infiltrated the workflow of Austrian dentists with predictions of growing implementation amongst dental practices in the future.
... CAD/CAM technologies allow for the restorations and dental prostheses. [12] The uses of CAD/CAM in various fields of Prosthodontics are continuously increasing for the past two decades. This technology is not only used in dental laboratories but is also being used in dental clinics to make chair-side restorations. ...
commons attribution noncommercial License. Which allows others to remix, tweak, and build upon the work non commercially, as long as appropriate credit is given and the new creations are licensed under the identical terms. Abstract Aim: This study was aimed to highlight the role of geometric modeling in prosthodontics. Methodology: A systematic literature search was performed electronically and hand-searched with terms of geometric modeling, geometric modeling in dental materials, geometric modeling in prosthodontics, and CAD-CAM. For articles published between 2015 and 2020, a search was carried out using Medline through Pubmed and Google Scholar. A total of 296 articles were found-critically appraised articles selected to evaluate their quality. Results: Different articles described various fields included the application of geometric modeling, pertaining primarily to prosthodontics. The literature search revealed 115 articles in PMC. 153 articles in google search. Additional 28 articles were identified by hand search. Conclusion: Accurate geometric modeling is essential for CAM processes and stress analysis checks. The designs interpreted by geometric modeling are more accurate and precise when compared to conventional techniques.
The aim of this review article is to present various ceramic materials currently utilized in the field of CAD/CAM. Due to high aesthetic and functional demands of indirect restorations research on dental materials is increasing. Comparing the materials will take into account their mechanical properties, their clinical usage, their advantages and disadvantages.
The aim of this review article is to present various ceramic materials currently utilized in the field of CAD/CAM. Due to high aesthetic and functional demands of indirect restorations research on dental materials is increasing. Comparing the materials will take into account their mechanical properties, their clinical usage, their advantages and disadvantages.
Objectives: Computer-aided design/computer-aided manufacturing (CAD/CAM) technology transformed the world of restorative dentistry. The objectives were to assess pre-doctoral dental students' CAD/CAM-related education, knowledge, attitudes, and professional behavior, and to explore the relationships between the year in dental school and these constructs. Methods: A total of 358 pre-doctoral dental students from 17 of the 68 US dental schools responded to a web-based anonymous survey. Results: CAD/CAM-related classroom-based education was likely to happen in lectures (87.2%) and simulated exercises as part of a class (86.9%). Faculty were most likely to provide CAD/CAM instruction (87.9%), with staff (44.8%) and dental technicians (20.2%) being engaged as well. Preclinical education included video demonstrations (81.8%), demonstrations during a lecture (76.4%) or for smaller groups of students (69.2%), hands-on workshops (65.6%), and individual instruction (50.4%). Considering the digital workflow in clinics, 45.2% reported using intraoral scans. The more advanced the students were in their program, the more CAD/CAM knowledge (r = 0.27; p < 0.001) and knowledge about what can be fabricated with CAD/CAM technology they had (r = 0.25; p < 0.001). However, the student's satisfaction with the education about CAD/CAM did not increase over the years (r = -0.04; n.s.) and remained neutral, while their attitudes became more positive the longer they were in dental school (r = 0.13; p < 0.05). Their attitudes were quite positive, with most students considering that CAD/CAM is the future of dentistry (5 = most positive: Mean = 4.34), agreeing that they enjoyed working with CAD/CAM (Mean = 4.11) and that CAD/CAM has the potential of making them a better dentist (Mean = 4.07). Conclusions: The majority of students in the US dental schools appreciate CAD/CAM technology, consider it to be the future of dentistry, and believe it makes them better dentists. The fact that the majority is not satisfied with their classroom-based, preclinical and clinical CAD/CAM-related education should therefore be a call to action to rethink dental school curricula in this content area.
Mesoscale periodic structures have been fabricated via directed assembly of colloidal inks. Concentrated colloidal gels with tailored viscoelastic properties were designed to form self-supporting features. The inks were deposited in a layer-by-layer sequence to directly write the desired 3-D pattern. Periodic structures with spanning features that vary between ∼100 µm and 1 mm were assembled. Shear rate profiles were calculated on the basis of the measured rheological properties of the inks under slip and no-slip boundary conditions during flow through a cylindrical deposition nozzle. Deflection measurements of spanning elements were used to probe the relationship between gel strength, deposition speed, and shear rate profiles in the nozzle. These observations revealed that the ink adopted a rigid (gel) core-fluid shell architecture during assembly, which simultaneously facilitated bonding and shape retention of the deposited elements.
In dentistry the specific interactions between ultrashort laser pulses and enamel/dentin of atooth[1] or ceramic restoration materials[2] are advantageous due to minimal collateral damage. The femtosecond laser beam can be used as atool to remove either decayed enamel/dentin – also named caries – or as atool to remove ceramic from abulk until the shape of an all-ceramic restoration is left. Therefore acompletely new caries therapy and an innovative way to manufacture all ceramic dental restorations are possible if femtosecond laser devices emitting pulses with ahigh energy and repetition rate are available. Although the latter has not become acommercial possibility yet, basic research has to be done to evaluate the interactions between lasers and materials depending on various laser parameters. This strategy enables a specific development of dental femtosecond laser sources based on optimized laser parameters. Additionally the high demand of an intraorally application of a femtosecond laser beam can be met by developing adental handpiece.
Procera Sandvik AB is now manufacturing a densely sintered high-purity alumina core for an all-ceramic crown designed for anterior and posterior restorations. Whereas the material holds promise on the basis of in vitro strength tests, the ability to alter the surface and use conventional bonded resin cements has not been reported previously in the literature. Samples of the core were treated by means of one of four methods routinely used for all ceramic restorations, and then a commercially available resin cement was bonded to the surface. A shear bond test of the adhesion showed that the highest shear bond strengths of 11.99 +/- 3.12 MPa were obtained with air abrasion at 80 psi and 50-microm alumina particles.
The swaged metal matrix provides a method for rapidly making a metal substructure for ceramic crowns. This study determined the vertical and horizontal marginal fidelity of swaged metal substrate crowns made with four methods. No significant difference in vertical or horizontal marginal fidelity was found for metal margin crowns formed with either a plastic spacer or a paint-on die spacer. The vertical marginal fidelity was significantly better in crowns made with a metal margin (37 microns) than in crowns made with a porcelain facial margin (62 microns), and the latter were significantly better than crowns made with a 360-degrees porcelain margin (86 microns). Crowns made with all four methods were overcontoured by 46 to 82 microns. The 360-degrees porcelain margin was technically more difficult and time-consuming to make.
The purpose of this study was to evaluate the marginal adaptation of all-porcelain labial margin metal ceramic crowns using a porcelain shoulder material containing a light-polymerizing resin and one that used a direct-lift technique. Conventional metal margin restorations served as controls. Scanning electron micrographs were made of a 1-mm mesiodistal width of the margin at midfacial and midlingual reference marks. Image processing and analysis techniques were accomplished using a computer. Statistical evaluation indicated that the mean labial marginal discrepancy of the control group was significantly less than that of either of the two porcelain shoulder methods.
The terms bevel, chamfer, and shoulder are widely used to describe crown margin designs. However, as no clear definition of the essential feature(s) of each design has been universally accepted, the same term often describes margins of widely differing width and/or configuration. Similarly "bevel angles" are not consistently defined. While tradition favors the use of thinner marginal designs, many of the reasons advanced for their superiority are questionable in the light of contemporary research. Use of marginal widths beyond the absolute minimum demanded of the material may contribute to overcoming some of the persistent problems identified with fixed prosthodontic replacement of natural teeth. These include overcontour, porcelain debonds, poor esthetics, and fit. It is suggested that the problems associated with underpreparation and the potential advantages of wider preparations need reemphasis.
The CAD-CAM CEREC system is a small, complex unit developed for electronically designing and milling ceramic restorations. The system makes it possible to generate a restoration without taking impressions, developing temporary prostheses, and without laboratory assistance. The entire restorative procedure is performed in one appointment. Basic features include the following: the cavity preparation is scanned stereo-photogrammetrically, using a three-dimensional miniature video camera; the small microprocessor unit stores the three-dimensional pattern depicted on the screen; the video display serves as a format for the necessary manual construction via an electrical signal; the microprocessor develops the final three-dimensional restoration from the two-dimensional construction; the processing unit automatically deletes data beyond the margins of the preparation; the electronic information is transferred numerically to the miniature three-axis milling device; driven by a water turbine unit, the milling device generates a precision-fitting restoration from a standard ceramic block; the entire process of electronic designing and subsequent milling of a ceramic restoration requires approximately 10 to 15 minutes.