3D printing in dentistry IN BRIEF

Discusses the latest technologies in 3D

imaging and printing that can be applied

PRACTICE
A. Dawood,* B. Marti Marti, V. Sauret-Jackson and A. Darwood
1 1 2 3 in dentistry.
Suggests these technologies could be
used in daily practice.

3D printing has been hailed as a disruptive technology which will change manufacturing. Used in aerospace, defence,
art and design, 3D printing is becoming a subject of great interest in surgery. The technology has a particular resonance
with dentistry, and with advances in 3D imaging and modelling technologies such as cone beam computed tomogra-
phy and intraoral scanning, and with the relatively long history of the use of CAD CAM technologies in dentistry, it will
become of increasing importance. Uses of 3D printing include the production of drill guides for dental implants, the
production of physical models for prosthodontics, orthodontics and surgery, the manufacture of dental, craniomaxil-
lofacial and orthopaedic implants, and the fabrication of copings and frameworks for implant and dental restorations.
This paper reviews the types of 3D printing technologies available and their various applications in dentistry and in
maxillofacial surgery.

INTRODUCTION
The term 3D printing is generally used to
describe a manufacturing approach that builds
objects one layer at a time, adding multiple
layers to form an object. This process is more
correctly described as additive manufacturing,
and is also referred to as rapid prototyping.1,2
3D printing technologies are not all new;
many modalities in use today were first devel-
oped and used in the late 1980s and 1990s3 the
author first treated a patient with the help of
3D printing in 1999 (Fig.1).
The term 3D printing, however, is relatively
new, and has captured the public imagina-
tion. A great deal of hype surrounds the use Fig. 1 The first patient treated by the author with the help of 3D printing in 1999. (a) Frontal
of 3D printing which is hailed as a disruptive view of the 3D printed medical model, printed with FDM technology, which shows the complex
technology that will forever transform manu- anatomy of the patients cleft palate, before implant placement. (b) A recent image of the
patient with implant supported bridgework in place
facturing. We have seen headlines in the inter-
national press describing the use of 3D printing
to produce everything from fashion wear and
architectural models to armaments (Fig. 2).
However, the reality is different; 3D printed
underwear would today be uncomfortable and
3D printed guns are dangerous to the indi-
vidual firing them. While we are very many

1
Dawood and Tanner Dental Practice, 45 Wimpole St,
London, W1G 8SB; 2Cavendish Imaging, London, 109
Harley St, London, W1; 3University of Nottingham
Medical School, Queens Medical Centre, Nottingham,
NG7 2UH
*Correspondence to: Dr A Dawood,
Email: andrewdawood@hotmail.com Fig. 2 (a) A 3D printed colour plaster architectural model of one of the most iconic
examples of twentieth-century religious architecture designed by Le Corbusier. Model
Refereed Paper printed by digits2widgets.com. Photograph Chris Sullivan. (b) 3D printed gun. Production
Accepted 6 October 2015 file controversially disseminated on the internet by American Cody Wilson, produced by
DOI: 10.1038/sj.bdj.2015.914
British Dental Journal 2015; 219: 521-529
digits2widgets.com for Londons Victoria and Albert Museum collection

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 PRACTICE

years away from seeing the production of via- of creativity and an understanding of tech- APPLICATIONS OF 3D PRINTING
ble 3D printed organs, dentistry and oral and nology, including engineering and materi- IN DENTISTRY AND ORAL AND
maxillofacial surgery have used 3D printing als skills that extend well beyond that of MAXILLOFACIAL SURGERY
for years, and have whole-heartedly embraced many others working in individual fields of
the use of digital manufacturing technologies, endeavour. Medical modelling
notably, the use of computer-aided design and Dentistry has a long association with One of the earliest applications of 3D printing
manufacturing. This article sets out to explore subtractive manufacturing6 more usually in surgery, medical modelling, may be thought
why 3D printing is important to dentistry, and described as milling. Subtractive manufac- of as the production of an anatomical study
why dentistry motivates development in 3D turing is the removal of material to form an model.12 This has been made all the more
printing applications. object. CAD CAM for the milling of crown accessible by another important technology
copings and bridge frameworks is now syn- that has become mainstream in dentistry in
3D PRINTING TECHNOLOGY onymous with modern dental technology.5 recent years; CBCT has become widely avail-
From a mechanical perspective, 3D print- Modern dentistry has a familiarity with able in dental practices13,14 and has trans-
ers are often quite simple robotic devices. materials designed to work with CAD CAM formed diagnosis and treatment in implant
The apparatus would be nothing without and to substitute for the more traditional dentistry15,16 and in endodontics.17-19 Ready
the computer-aided design (CAD) software precious metal casting alloys,7 which have access to CT, which provides similar data and
that allows objects, and indeed whole assem- been subject to exponential price increases is more prevalent in a hospital setting, or CBCT
blies to be designed in a virtual environment. in recent years. This use of technology means that it is possible to provide volumetric
CAD software is commonplace in industrial facilitates the use of materials, which would image data to a 3D printer before surgery20
design, engineering, and manufacturing otherwise be hard to work with, and elimi- and to make detailed replicas of the patients
environments, and is also common in the nates labour intensive artisanal production jaws. This allows anatomy, particularly com-
dental laboratory; it is even becoming a fea- techniques,8 allowing the dental technician plex, unusual, or unfamiliar anatomy, to be
ture of many dental surgeries (Fig. 3). to focus his manual skills on more creative carefully reviewed and a surgical approach
Developments in computer technology and aspects of the manufacturing process, for planned or practised before surgery.21,22
software applications are very much a part of example the aesthetic layering of porcelain. This has led to the development of new
the groundswell of technological change that Of course every time that a dentist oper- procedures and approaches to surgery23 and
has taken 3D printing to where it is today. ates to provide a restoration or reconstruc- along with the production of drilling or cut-
For 3D printing to have value we need to be tion, the procedure is unique to that patient, ting guides using 3D printed technology or
able to create objects to print; CAD software that jaw, that tooth, or that implant. The conventional laboratory technology, can
allows us to create objects from scratch,4,5 reconstruction or restoration will also have lead to expedited, less invasive, and more
but in dentistry and surgery we also have innate complexity requiring the reproduc- predictable surgery24,25 (Fig.4).
ready access to volumetric data in the form tion of convoluted geometry with a high For medical modelling, accuracy will
of computed tomography (CT) data, cone level of precision.9 Although multi-axis CAD often be constrained by the original imag-
beam computed tomography (CBCT) data, CAM milling processes will allow this to an ing modality and the presence of artefact26
and intraoral or laboratory optical surface extent,10 the process is slow and wasteful as caused by metal structures such as teeth,
scan data. Recent developments in CBCT and the material is milled from an intact block, restorations or implants; the level of inac-
optical scan technology, in particular, have and accuracy is limited by the complexity curacy is unlikely to be clinically relevant for
revolutionised, and are profoundly chang- of the object, the size of the tooling, and many surgical applications. A wide variety
ing many aspects of restorative and implant the properties of the material. 3D printing, of 3D printers and 3D printing materials can
dentistry. These powerful technological tools however, comes into its own for the accurate be used to print medical models, but as it is
are at the disposal of a class of individu- one-off fabrication of complex structures in useful to have such models in the operating
als dentists and dental technicians who a variety of materials with properties that are room, materials that can be sterilised, such
are often polymaths, having a broad level highly desirable in dentistry and in surgery.11 as nylon, are particularly interesting.27

1. Acquisition of 3D 2. Creating Design 3. Preparing the 4. 3D Printing 5. Post Processing

patient model STL FILE model for printing

PHYSICAL MODEL When necessary support Removal of support

structures are designed Sandblasting/Jet-washing/
in the software. Grinding
The structure is sliced to Infiltration
create a stack oaf layers Heat treatment (for metal
objects)
Or Model/Appliance/Prosthesis The sliced data is sent to
designed in CAD software the printer, where material
DIGITAL MODEL is laid down layer by layer

The scanned volume is

exported, typically as
DICOM or OBJ data

Fig. 3 3D printing process

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Fig. 4 Models and drill guides printed in resin for simultaneous Full lower arch implant rehabilitation and mandibular reconstruction. (a) Implant
drill guide over the 3DP model. (b) Bending the osteosynthesis plate on the sterilised medical model. (c) Plate in place.

Drilling and cutting guides

These engineering tools need to be robust
and precise, as well as being capable of steri-
lisation or disinfection as used in a surgi-
cal environment.28 The use of drill guides
in implant dentistry is becoming com-
monplace,29 and this technology has been
embraced in orthopaedics for total knee
replacement,30 for example. The use of drill
guides and cutting guides allows a virtual
3D plan, created on-screen in software to
be transferred to the operative site,31,32 and
as such may be thought of as an interface
between the virtual plan and the physical
patient (Fig.533).
Inaccuracy resulting from the scan modal-
ity, software, and the presence of artefact
may be clinically relevant for dental implant
procedures or where prostheses are prefab-
ricated to precisely fit a pre-planned post-
operative result.34 Precise 3D printers and
high-resolution printing materials must be
utilised for implant drill guides unfortu-
nately, some of the best materials that may
be used for this purpose are not autoclavable.
Fig. 5 Use of a 3D printed SLS drill guide to accurately sculpt a facial tumour (fibrous
Crown copings and partial denture dysplasia)33.(A) Preoperative appearance. (B) Virtual surgical planning. (C) 3D printed drill/
frameworks sculpting guide in place. (D) Guided drilling with help of a second drilling/sculpting guide

With the use of intraoral optical scanners or

laboratory scanners it is possible to develop
a precise virtual model35,36 of the prepared
tooth, implant position,37 and the dental
arch.36,39 In fixed and removable prosthodon-
tics, treatment may be planned and restora-
tions designed in CAD software. This scan
data and CAD design may be used to mill
or print crown or bridge copings, implant
abutments, and bridge structures.
3D printing may be harnessed for the fab-
rication of metal structures40 either indirectly
by printing in burn-out resins or waxes for Fig. 6 3D manufacture of metal crown copings. (a) Selective laser sintering in progress. (b)
a lost-wax process, or directly in metals or Printed copings in cobalt chrome alloy tethered to build platform by support structue. (Images
metal alloys.8 The advantage of printing courtesy of EOS, GmbH)
in resin/wax and then using a traditional
casting approach is that there is much less use of more costly technologies which have When printing elaborate implant bridge
post-processing involved than in the direct their own very specific health and safety structures 3D printing may be used in con-
3D printing of metals;41 casting alloys and requirements, and demand a great deal of junction with milling/machining technolo-
facilities are also familiar and widely avail- post-processing before components may be gies to produce a high precision mechanical
able. Printing directly in metals requires the ready for use42 (Fig.643). connection to the implant combining the

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 PRACTICE

best attributes of printing complex geom- or even CBCT to capture patient data. The
etry with little waste with milling high Invisalign, system digitally realigns the
precision mechanical connecting surfaces. patients teeth to make a series of 3D printed
While it may be somewhat wasteful in models for the manufacture of aligners,
material, milling has the advantage that the which progressively reposition the teeth over
material used is intrinsically homogeneous a period of months/years.45,46 An example
and unaffected by operating conditions. of printing with multiple materials is in the
There is little need for post-processing, and manufacture of 3D printed, indirect bracket-
the equipment is considerably less costly. bonding splints, printed in rigid and flexible
materials for precise bracket placement using
Dental models for restorative orthodontic CAD software (3Shape).47
Fig. 7 SLS printed prepared teeth, printed dentistry As data travels through the internet, and
from data from an intra oral scanner
The trend towards the use of intraoral scanners smile design takes place in software, there
means that dentists need 3D printing in order are huge potential savings in time. Again,
to make a physical model of the scanned jaw. patient data may be digitally archived, and
Although today, it is not always strictly only printed when needed, with great savings
necessary to print a master model at all,44 the in physical storage-space requirements.
3D printed master model (Fig.7) may be used
for conventional aspects of the fabrication Dental implants
of a restoration, such as adding a veneering Manufacturers have used 3D printing technol-
material, and we are accustomed to seeing ogy to create novel dental implants32 with a
restorations displayed on a model even porous or rough surface.48 We must be careful,
if they have been directly fabricated digi- however, not to be seduced by the attraction of a
tally. Patient model data may be digitally rough or porous surface; over the years we have
archived, and only printed when needed, seen many dental implants appear with rough or
easing storage requirements. porous surfaces only to disappear as problems
became evident some years later.4951 However,
Digital orthodontics as a method for producing batches of complex
In orthodontics, treatment may be planned dental implants, 3D printing has the ability to
Fig. 8 Cranioplasty and orbital rim implants and appliances created, or wires bent roboti- produce complex geometries, such as a bone-
in titanium or PEEK fitted to a 3D printed SLS cally based upon a digital workflow using like morphology, which may not be produced
model (Courtesy of www.cavendishimplants.com)
intra oral or laboratory optical scanning by milling alonealthough milling/machining
may also be used to refine the printed formfor
example, the implant platform. There is also the
opportunity to create implants which have com-
plex geometry, although ultimately inserting a
dental implant using a screw type form seems
like a well proven approach.

OMF implants
Much has been made of the ability to print in
titanium or in implantable polymers (notably
Poly ethyl ether ketone [PEEK]52) to create max-
illofacial implants53,54 (Fig.8). 3D printing is capa-
ble of producing complex geometries, however,
most OMF implants are actually quite simple in
form; pressing and milling technologies have
several distinct advantages, such as reduced post-
processing, quick production, and the predict-
able use of homogeneous and uniform materials.
3D printing may be used to print the implanted
structure directly, or as a tool for indirect manu-
facture using a conventional pressing process.

Product design and instrument

manufacture
Surgeons in general, and dentists certainly,
are known for their creativity and ingenu-
ity! 3D printing has a role in the rapid
prototyping of instrumentation, which
allows creative individuals to take an idea
Fig. 9 Back-of-envelope design, leads rapidly to a functional prototype for a 3D printed saline to fruition in a very short period of time.
bag holder, fitted to dental chair
Perhaps a reason why the term 3D printing

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caught the publics imagination, whereas disadvantages (Table 1). Unfortunately, a Supports must be generated in the CAD
rapid prototyping never seemed that excit- common feature of the more functional and software, and printed to resist the wiping
ing, is that while the technology allows productive equipment is the high cost of the action and to resist gravity, and must later
the surgeon-designer to move rapidly from equipment, the materials, maintenance, and be removed from the finished product. Post-
concept to prototype product, the actual repair, often accompanied by a need for messy processing involves removal of excess resin
printing process itself is rather slow and cleaning, difficult post-processing, and some- and a hardening process in a UV oven.
costly when working with materials with times onerous health and safety concerns. The process is costly when used for large
useful mechanical properties. objects, but this technology is commonly
The authors have used 3D printing to pro- Steriolithography (SLA, SL) used for the industrial production of 3D
duce several prototype designs for innova- A stereolithography apparatus (Fig. 1055) printed implant drill guides.
tive or mundane instruments or devices used uses a scanning laser to build parts one
in everyday practice (Fig.9). layer at a time, in a vat of light-cured pho- Photopolymer jetting (PPJ)
topolymer resin. Each layer is traced-out by This technology uses light cured resin materials
3D PRINTING TECHNOLOGIES AND the laser on the surface of the liquid resin, and print heads rather like those found in an
MATERIALS at which point a build platform descends, inkjet printer (but considerably more costly),
Many different printing technologies and another layer of resin is wiped over the to lay down layers of photopolymer which are
exist, each with their own advantages and surface, and the process repeated. light cured with each pass of the print head.

Table 1 3D printing modalities and materials

Techniques Advantages Disadvantages

Light cured resin

Only available with light curable liquid polymers.
1- Stereolithography (SLA) Rapid fabrication. Support materials must be removed . Resin is messy
Light sensitive polymer cured layer by layer by a Able to create complex shapes with high feature resolu- and can cause skin sensitisation, and may be irritant by
scanning laser in a vat of liquid polymer tion. Lower cost materials if used in bulk. contact and inhalation. Limited shelf life and vat life.
Can not be heat sterilised. High cost technology.
Relatively fast.
2- Photojet - Light sensitive polymer is jetted
High-resolution, high-quality finish possible. Tenacious support material can be difficult to remove
onto a build platform from an inkjet type print-
Multiple materials available various colours and physi- completetly. Support material may cause skin irritation.
head, and cured layer by layer on an incremen-
cal properties including elastic materials. Lower cost Can not be heat sterilised. High cost materials.
taly descending platform.
technology.
Light curable liquid polymers and wax-like materials
3- DLP (digital light processing)
for casting. Support materials must be removed . Resin
Liquid resin is cured layer by layer by a projector Good accuracy, smooth surfaces, relatively fast.
is messy and can cause skin sensitisation, and may be
light source. The object is built upside down on Lower cost technology.
irritant by contact Limited shelf life and vat life. Can not
an incrementally elevating platform.
be heat sterilised. Higher cost materials.
Powder binder

Plaster or cementaceous material set by drops

Lower cost materials and technology.
of (coloured) water from 'inkjet' print head. Low resolution. Messy powder. Low strength. Can not be
Can print in colour. Un-set material provides support
Object built layer by layer in a powder bed, on soaked or heat sterilised.
Relatively fast process. Safe materials.
an incrementaly descending platform.

Sintered powder
Selective laser sintering (SLS) for polymers. Range of polymeric materials including nylon, elas-
Object built layer by layer in powder bed. Heated tomers, and composites. Strong and accuracte parts.
Significant infrastructure required, eg. compressed air,
build chamberraises temperature of material to Self-supported process.
climate control. Messy powders. Lower cost in bulk.
just below melting point. Scanning laserthen Polymeric materials commonly nylon may be auto-
Inhalation risk. High cost technology. Rough surface.
sinters powder layer by layer in a descending claved. Printed object may have full mechanical func-
bed. tionality. Lower cost materials if used in large volume.
Selective laser sintering (SLS) - for metals and Elaborate infrastructure requirements. Extremely costly
metal alloys. Also described as selective laser technology moderately costly materials. Dust and
High strength objects, can control porosity.
melting (SLM) or direct metal laser sintering nanoparticle condensate may be hazardous to health.
Variety of materials including titanium, titanium alloys,
(DMLS). Scanning laser sinters metal powder Explosive risk. Rough surface. Elaborate post-processing
cobalt chrome, stainless steel. Metal alloy may be recy-
layer by layer in a cold build chamber as the is required: Heat treatment to relieve internal stresses
cled. Fine detail possible.
build platform descends. Support structure used in printed objects. Hard to remove support materials.
to tether objects to build platform. Relatively slow process.
Electron beam melting (EBM, Arcam). Heated Extremely costly technology moderately costly materi-
High temperature process, so no support or heat treat-
build chamber. Powder sintered layer by layer als. Dust may be hazardous to health. Explosive risk.
ment needed afterwards. High speed. Dense parts with
by scanning electron beam on descending build Rough surface. Less post-processing required. Lower
controllled porosity.
platform. resolution.

Thermoplastic

Fused deposition modelling (FDM) High porosity. Variable mechanical strength. Low - to
Low cost but imited materials - only thermoplastics.
First 3DP technology, most used in 'home' print- mid-range cost materials and equipment. Low accuracy
Limited shape complexity for biological materials.
ers. Thermoplastic material extruded through in low costequipment. Some materials may be heat
Support material must be removed.
nozzle onto build platform. sterilised.

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droplets to infiltrate a layer of powder,

layer by layer. Typically a pigmented liq-
uid, which is mostly water, is used to print
onto the powder, which is mostly plaster of
Paris (Fig.11).
Again, a model is built up in layers as
the powder bed drops incrementally, and a
new fine layer of powder is swept over the
surface. The model is supported by un-infil-
trated powder, and so no support material
is required. Post-processing to infiltrate the
delicate printed model with a cyanoacrylate
or epoxy resin will improve strength and
surface hardness.
The resulting models are useful as study
models or visual prototypes, but accuracy47
is limited and the models are rather frag-
ile despite the post-processing. A particu-
lar excitement of this technology lies in its
ability to print models in full colour; from
a surgical perspective the drawback is that
the models may not be sterilised or directly
manipulated at operation.
Accuracy is inadequate for prosthodontic
Fig. 10 (a) diagram of SLS printing process (diagram courtesy of EOS, GmbH).61 (b) Industrial applications. The machines and materials are
SLS apparatus (image courtesy of www.digits2widgets.com)
lower cost, but still not inexpensive. As the
material is mostly plaster of Paris, there is
some compatibility with having the apparatus
situated in a dental laboratory plaster room.

Selective laser sintering (SLS)57

This technology has been available since the
mid-1980s.58 A scanning laser fuses a fine
material powder, to build up structures layer
by layer, as a powder bed drops down incre-
mentally, and a new fine layer of material
is evenly spread59,60 over the surface. A high
(60m) level of resolution may be obtained,
and as the structures that are printed are
supported by the surrounding powder, no
support material is required.
Polymers used in this process have high
melting points (above autoclave sterilisation
temperature) and excellent material prop-
erties,61,62 making objects made in this way
Fig. 11 Industrial powder binder printer and example bust of author captured with 3D useful as anatomical study models,63,64 cut-
photography and printed in full colour plaster of Paris (courtesy of www.digits2widgets.com)
ting and drilling guides, dental models, and
for engineering/design prototypes. However,
The technology may use a stationary platform in this way. Implant drill guides may be some of the materials are difficult to drill
and dynamic print head or a stationary print quickly and cheaply produced with this tech- and prepare, and the technology is costly
head and dynamic platform. A support struc- nology as they are less bulky. A particular to purchase, maintain, and run, therefore
ture is laid down in a friable support material. advantage of this technology is that the use requiring copious quantities of compressed
A variety of materials may be printed of multiple print heads allows simultaneous air. The materials are intrinsically dusty,
including resins and waxes for casting, as printing with different materials, and gradu- have some health and safety requirements,
well as some silicone-like rubber materials. ated mixtures of materials, makes it possible and are rather messy to work with.
Complex geometry and very fine detail is to vary the properties of the printed object, Materials available include nylon, which
possible56 as little as 16 microns resolution. which may for example have flexible and is perhaps the most versatile, flexible elas-
The drawback is that the equipment, and rigid parts, eg for the production of indirect tomeric materials, and metal-containing
materials are costly to purchase and run, and orthodontic bracket splints. nylon mixtures. An interesting possibility
the support materials can be tenacious and for medical implants is the use of polyether
rather unpleasant to remove. They are useful Powder binder printers (PBP) ether ketone (PEEK),65 although this requires
for printing dental or anatomical study mod- These apparatus use a modified inkjet head high temperatures and complex control
els, but these are expensive when produced to print using, what is essentially, liquid and a great deal of wastage.

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The ability to 3D print in metals is incred- used for bioprinting71 a popular area Although 3D printing apparatus and
ibly exciting in the dental world. There are for research in tissue engineering. Building technologies have been readily available
a broad range of metals and metal alloys complex geometries usually necessitates the for more than a decade, it is developments
available including titanium, titanium laying down of support structures which in, and access to scanner technology, com-
alloys, cobalt chrome alloys, and stainless may be either formed from the same mate- puter-aided design software and raw com-
steel. 3D printed partial dentures and pros- rial, or from a second material laid down putational power, that has started to make
thesis frameworks are already being made in by a second extruder which, for example, the use of the technology practical, while
this way, and for implant bridge frameworks might extrude a water soluble support mate- commercial and public interest has raised
technology may be combined with milling rial. Accuracy will depend upon the speed of awareness and improved access to resources.
processes to provide high precision connec- travel of the extruder, as well as the flow of With the introduction of milling tech-
tions. The technology is broadly the same as material and the size of each step. nology, a plethora of new material options
that described for polymers above, but these This is the process that is used by most became available for the production of
apparatus may also be described by different low cost home 3D printers. It allows for restorations; similarly, new generations of
manufacturers as, selective laser melting, or the printing of crude anatomical mod- dental restorative materials for 3D printing
direct metal laser sintering. els without too much complexity,57 for are under development and appearing on a
The 3D printing process itself may be example, printing an edentulous mandible regular basis.
straightforward, but post-processing is might be possible, though printing a detailed Taking into account the range of indica-
definitely not straightforward, and the fine maxilla would be a tall order. More costly, tions for 3D printing in dentistry, and the
metal powders and even finer nanoparticle more accurate FDM printers are available, professions long experience of scanning
waste represents quite a significant health and have application in anatomical study- and milling technology, it might be said
and safety challenge. While the printer itself model making, but little else in dentistry or that dentists and dental technologists have a
may be readily accommodated in the dental in surgery. broader experience of these 3D manufactur-
laboratory, the associated post production ing technologies than any other profession.
equipment takes up at least as much space. DISCUSSION CAD software is still the domain of the
While in theory the use of one machine to The profession is already accepting of digi- well-trained and computer literate, but this
print in different materials may seem fea- tal manufacturing technologies; much of the will not faze new generations of operator,
sible, in practice it is extremely difficult to laboratory work that was once produced by and the software is becoming smarter and
fully clean down a machine, and certainly artisan processes is now produced digitally, more user-friendly all the time. Key future
switching between an implantable metal and leaving only the final finishes of restorations developments that would drive forwards our
a restorative material is not at all practical. to be applied by hand. The use of CAD CAM usage of the technology beyond the obvious
In small batch production the technology technology has become commonplace in the benefits of reduced costs, increased speed of
is costly and casting continues to have many dental laboratory, and may be seen more and manufacture, and faster, less invasive treat-
attractions. However, in a large dedicated more in the dental surgery. Whereas early ments for our patients, include the potential
machine it is possible to simultaneously approaches to scanning and the production to 3D print in ceramic materials with digital
print 400500 crown copings in a 24hour of digitally manufactured restorations relied colouration and staining, the reduction of
period. Furthermore, copings may be printed upon the use of centralised scanning and the post-processing needed for metal parts,
in lower cost materials that are tradition- manufacturing facilities, many laboratories and the integration of machining/milling of
ally harder to work with than gold alloys, now have their own laboratory scanners, and 3D printed metal parts into the metal print-
such as cobalt chrome, but which offer good many also have their own milling units. In ing workflow.
porcelain bonding strengths and excellent the dental practice environment, intra oral All of this means that the slowly evolving
mechanical properties. and CBCT scanners are becoming more and use of digital technologies in dentistry has
In surgical applications, the technology more common. gathered momentum to the point that we are,
allows for the straightforward batch pro- All this means that dentists and dental in the opinion of the authors, long past the
duction of implants for orthopaedic appli- technicians are becoming well acquainted point of early adoption, with the opportunity
cations,66 and for dental implants,67 and has with, and adept at working with large vol- for mainstream use of 3D printing technol-
been considered for use in the production of umes of digital data. 3D printing offers ogy in the orthodontic and dental laboratory,
titanium cranioplasties in oral and maxil- another form of output device for dental and in surgery. There is scope for so much
lofacial surgery.68,69 CAD software; making it possible to materi- more development; while there is a great
alise intricate components and objects in a focus on individual items of equipment, it is
Fused deposition modelling (FDM)70 variety of different materials. It comes into the overall integration of the equipment with
FDM is one of the earliest 3D printing tech- its own when structures are unique, bespoke, the planning and design software to create a
nologies and was used by the author to have intricate geometry, and where 3D scan smooth, rigorous and streamlined workflow
produce his first medical model in 1999.An data is easily obtained. that is of key importance, and will make all
FDM printer is essentially a robotic glue gun; In dentistry, 3D printing already has the difference to the uptake and acceptance
an extruder either traverses a stationary plat- diverse applicability, and holds a great deal of these disruptive technologies.
form, or a platform moves below a stationary of promise to make possible many new and Along with this new technology comes
extruder. Objects are sliced into layers by exciting treatments and approaches to man- new opportunity; the challenge that we face
the software and coordinates transferred to ufacturing dental restorations. The national is to not look at 3D printing as a new tool to
the printer. Materials must be thermoplastic regulatory bodies have not yet implemented do what we have always done, but to look
by definition. A commonly used material is guidance in the use of 3D printing in sur- at it as a technology that will allow us to be
the biodegradable polymer polylactic acid; gery,72 or in dentistry, but at some stage there more creative, to develop new materials and
this or similar materials have been used will be a need for regulators to focus on this new more predictable, less invasive and less
as key components of scaffold structures technology to set appropriate standards. costly procedures for our patients. We must

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