The ‘right’ 3D printer and processes for an
in-office aligner system will vary according to
each practice’s particular goals and needs
Part 1 of 2
Advances in desktop 3D printing, the introduction of digital software
packages designed to help move teeth and the availability of various
thermoforming plastic films have all contributed to an era in
which orthodontic practices are able to adopt in-house protocols
to create their own clear aligners. This trend mirrors what’s happening in
the dental industry, where practices that have opted into digital dentistry
are manufacturing appliances such as surgical guides and crown and bridge
What is an in-office
Aligner therapy has significantly
changed since its inception in the 1970s.
Utilizing CAD/CAM technology to fabricate
aligners was the first major shift in
aligner therapy, when Align Technology
automated the tedious process of creating
aligners that conventionally had been done
in-office or at a local dental lab. Fast-forward
to 2021, and we have a plethora of clear
aligner systems, differentiated through
parts of the system process. For example,
the SureSmile Advanced platform allows
the combination of fixed appliances with
aligners, and the Clear X Aligner system
claims reactivation of aligners.
Along with the expansion of commercially
manufactured aligners, orthodontists
and dentists began to make clear aligners
in-house. Advances in desktop 3D printers
and the introduction of various digital platforms
to move teeth significantly accelerated
the adaption of this protocol.
The four components of an in-office
aligner (IOA) system are:
This article seeks to provide an overview
on these aspects.
- The aligner manufacturing process.
- The thermoplastic film of choice.
- The brand identity of these aligners.
- The indication of in-house fabricated
aligners for orthodontic care.
Why do I need to set up
an in-office aligner system
in my practice?
Before getting deep into the components
of an IOA system, let’s go over the benefits of
implementing this protocol in your practice.
Digital technology has become an
integral part of our daily practice. From
a macro-level view, most practices use
digital practice management software
to address daily administrative tasks,
including tracking patient care, managing
financial aspects of the treatment, and
communicating with patients over emails
or texts. From the patient care perspective,
digital technology ranges from a simple
use of digital photography for diagnostic
purposes to 3D-printing appliances to
render the therapeutic care. Cone-beam
computed tomography (CBCT) units
and 3D intraoral scanners are becoming
common equipment in dental practices,
so a growing group of practices has begun
3D-printing dental models or appliances.
In sum, digital dentistry is here to
stay. From the financial and patient care
perspectives, it makes sense to adapt our
daily practice style to maximize the use of
digital technology in hand.
How does a provider benefit from an
IOA system? This journey often starts
with buying a 3D printer to fabricate clear
retainers in-house. Cost reduction and
quick turnaround are the primary reasons
for making clear retainers from 3D-printed
dental models in-house. The next logical step
forward is to establish protocols to help with
active clear retainers—specifically, fabricating
one or a few clear retainers (i.e., aligners)
designed to move a limited number of
teeth to improve minor misalignments.
Some providers push this further to fabricate
aligners for limited or comprehensive
Access to on-demand aligner options
opens possibilities in daily practice of
orthodontics. However, this does come
at the expense of challenges to set up and
maintain an in-office aligner system.
It is essential to identify the main reason
you want to set up an IOA system (Fig. 1).
Are you planning to use in-house fabricated
aligners for patients who need correction of
minor relapse, limited nine-month orthodontic
care or comprehensive care? Are you
going to treat some malocclusions with a
hybrid appliance, mixing fixed appliances
with aligners? Do you want to have a fulltime
digital technician? Answers to all these
questions help you to morph the extent of
your in-office aligner system.
How can I implement
an in-office aligner system
in my daily practice?
Components of an in-office aligner
system are similar to a third-party manufacturing
system, despite relevant adjustments
in each step matching the process to a
smaller yet customizable scale. One ought
to harness the customizability of in-office
aligners; for example, the gingival trim line
can be adjusted based on the treatment
plan. Additionally, a hybrid appliance (fixed
appliances and aligners) can be fabricated
with localized selective blackouts to optimize
the retention of the aligner.
Fig. 1: A schematic representation of technology adoption. From left to right, these providers
opt not to establish an in-house appliance fabrication to full integration of in-house
appliance fabrication, respectively.
The aligner manufacturing cycle (Fig. 2)
divides into digital and analog segments.
Each part entails various components.
3D dental model acquisition
All dental scanners that allow the export
of 3D mesh dental scans can be used to
capture teeth and gum data from patients,
but as Zimmermann et al. reported in a
2010 JADA article, certain scanners perform
better in full-arch scans than others. Several
other factors will also help dictate what is
considered an “ideal” scanner for a practice.
The most common factors include:
Fig. 2: Aligner manufacturing cycle.
Trios by 3Shape, iTero by Align Technology
and Medit are perhaps the common
scanners. Most practices start with one
scanner and gradually transition into a
second and third scanner as their digital
services expand. It would be practical to keep
multiple scanners on the same brand for the
consistency of patient experience, training,
inventory and the scan files database.
- The initial financial investment
required to purchase the scanner
and a dedicated computer.
- Cost of consumables such
as scanner sleeves.
- Annual subscription fees.
- Available training and
- Available software packages.
In an IOA system, scans will be prepared
locally by a practice team member before
designing the tooth movement. The quality
of 3D meshes significantly affects the quality
of appliances fabricated from these scans.
Practitioners are encouraged to develop a
scanning best practices guideline (Table 1)
to minimize poor-quality scans.
Aligner digital software
Digital software packages for an IOA
system have been expanding in the past
few years. Certain software suites provide
features such as digital indirect bonding as
well as aligner therapy. The packages offer
Table 1: Scanning best practices.
Maestro 3D, uLab Systems, 3Shape
Aligner Studio and SureSmile are examples
of digital platforms one can use for an
IOA system. The most common pricing
models for these software packages are
either charges per digital model export or
charges per case treatment.
- Preparing mesh models and
segmenting the teeth.
- Developing a digital therapeutic
treatment plan, including the
biomechanics and choice of
- Generating 3D printing-friendly
3D dental models.
The cost associated with this software
is only one aspect that a provider should
assess when evaluating various choices
on the market, however. The time spent
in each step, starting with importing a
dental model to exporting a file ready for
3D printing, is another critical factor when
selecting the optimal platform for your
practice. Besides the workflow to create
models for aligners, auxiliary features such
as attachment varieties or pontic protocols
should also be evaluated.
In sum, the “ideal” aligner digital
software will vary by clinic. One should
clearly spell out the practice needs before
comparing these software packages (Table 2).
Desktop 3D printers have become more
affordable and easier to operate. Additive
manufacturing has been significantly adapted
in certain fields, including dentistry and
medicine; orthodontics has integrated it
before many other sectors of dentistry.
Table 2: A checklist to help identify and rank the ideal aligner software platform for your practice.
3D-printing dental models to thermoform
the aligners is a critical step in the
aligner manufacturing cycle. This step can
become a bottleneck and add stress to the
daily operation in a practice.
A common question about 3D printers
is, “I finally decided to start 3D printing.
Which printer do you recommend?” Before
we dive deep into information on desktop
3D printers, let’s look at the four core
attributes of an in-office 3D printer. An
optimal one should work well with these
four main concerns:
Someone’s printer of choice will change
based on the priority ranking of these
attributes. For example, a practice that will
create 100 models per week might opt for a
different printer than a practice that needs
only 10 models per week on average.
- Reproducibility: It should print
accurate parts at 95% success rate
- Print time: It needs to match the
weekly demand of a practice.
- Adaption learning curve: It should
require only reasonable levels of
maintenance and training to operate.
- Economics: Its cost of operation
must be reasonable, too.
It is important to mention that the
initial cost of 3D printing adaption is often
a primary driver in choosing a printer. With
multiple options on the market, it doesn’t
make sense to spend more than $10,000 on
a 3D printer at this point.
Dr. Rooz Khosravi is a clinical
assistant professor at the
University of Washington and
speaks on implementation
of in-office aligner systems
and 3D printing. Khosravi
also established the Digital
Orthodontics Hub, a study club
that offers training courses on digital orthodontics.
In addition to private practice and academic life, he is
an orthodontist-scientist consultant at uLab Systems,
SprintRay and Bay Materials. In these capacities, he
assists with accelerating the development of advanced
software and materials for digital orthodontics.