Chairside 3D digital design and trial restoration workflow

DENTAL TECHNIQUE

Chairside 3D digital design and trial restoration workﬂow

Christian Coachman, DDS, CDT,

Ralph Georg, MSc,

Lauren Bohner, DDS, MSc, PhD,

Lindiane Cogo Rigo, DDS, MSc,

and Newton Sesma, DDS, MSc, PhD

Virtual smile design software

and applications (apps) have

been used to create a digital

restorative design from

which it is possible to visu-

alize the deﬁnitive outcome

and to present it to the pa-

tient before the restorative

procedures begin.

1-8

Different systems have been

available for designing the

smile; however, a challenge

of the available systems is to

reproduce the 2D planning

in 3D.

Despite the

currently available digital

technology for 3D virtual planning,

10-12

the integra-

tion between 3D data acquired from scanning systems

and 2D images is usually limited to a single view

mode, which may limit the accuracy of the smile

design technique.

A further limitation is th e time required to repro-

duce the digital planning on a trial restoration suitable

forclinicaluse.Thecompletedigitalworkﬂow is usu-

ally restricted because current software programs do

not support chairside acquisition of the planned trial

restoration.

The 3D smile design project can be

exported as a complete cast standard tessellation lan-

guage (STL) ﬁle or as a template STL ﬁle

to a

computer-aided design (CAD) software program, a

milling machine, or a printer. In most situations, this

workﬂow is only possible by having the virtual cast

printed at a center, which can be a time-consuming

and expensive procedure (Table 1)anddemandsa

complex labor atory CAD software program with an

extended learning curve.

Conversely, chairside

printing of resin matrices makes the treatment more

straightforward and faster because the digital planning

and the clinical evaluation can be performed during

the same appointment (Fig. 1).

Integration of the 2D and 3D data and chairside

acquisition of the 3D printed resin templates are possible

by means of a 3D digital smile design app (DSDApp 3D)

for chairside esthetic planning, smile simulation, 3D

virtual waxing, and printed trial restorations made with a

portable device.

Private practice and DSD Founder, São Paulo, Brazil.

CoFounder, DSDApp, Miami, F la.

Postdoctoral student, Department of Prosthodontics, University of São Paulo, São Paulo, Brazil.

DSD education coordinator, DSD App, New York City, NY.

Professor, Department of Prosthodontics, University of São Paulo, São Paulo, Brazil and Private practice, São Paulo, Brazil.

ABSTRACT

Different digital tools have been used in clinical practice to assist in the planning and rehabilitation

of patients. Some applications (apps) and software programs used in esthetic planning allow

simulation of the smile design, improving communication between patients and professionals.

Nonetheless, they are usually difﬁcult to use, time-consuming, unattractive to present to the

patient, and complicated to link with the 3D workﬂow. This article presents a new 3D digital

smile design app for esthetic planning, smile simulation, chairside 3D virtual wax pattern, and

trial restoration performed with portable devices. In this technique description, a facial frontal

photograph, a facial scan standard tessellation language (STL) ﬁle, and a maxillary intraoral scan

STL ﬁle were uploaded to the app. The ﬁles were calibrated to each other to allow a 3D facially

driven smile design project. The deﬁnitive maxillary 3D digital waxing of facial templates was

exported to a 3D printer as an STL ﬁle. The printed resin templates were directly placed in the

mouth with ﬂowable composite resin for an immediate trial restoration without the need for

casts, silicone guides, or autopolymerizing resin. The workﬂow presented in this article linked the

3Dapp project to a printer and allowed straightforward chairside trial restorations. (J Prosthet

Dent 2019;

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TECHNIQUE

1. Start with the patient digitalization. A frontal facial

smiling phot ograph and a facial scan are all that is

needed for a facially driven digital smile design.

Reference lines and vertical and horizontal angles

presented on the app will h elp capture the photo-

graph with the best angulation and positioning.

Facial scan ﬁles made with another device can

be added or can be captured directly on the

DSDApp using the in tegratio n with a 3D face app

(Bellus 3D) .

2. Scan the maxillary arch by using an intraoral

scanner (IOS) to obtain an STL ﬁle. The app accepts ﬁles

from any IOS. After importing the STL ﬁle and saving the

patient’s documentation, choose DSD Cloud to securely

store the ﬁles. These can be opened and visualized on the

DSDApp iPad version (Apple) to continue with the smile

design (Fig. 2).

3. After patient digitalization, adjust the position of

the maxillary cast ﬁle and determine the pivot on the

virtual cast, which represents t he axis around which

the 3D cast will rotate (Fig. 3). The automatic facial

ﬂow of the DSDApp will help determine any facial

asymmetri es for an i mproved smile design (Fig. 4A,

4B). Then, superimpose the virtual cast and the facial

STL ﬁle on the photograph based on the size and

position of the anterior teeth (Fig. 4C). Calib rate the

occlusal view by determining the new occlusal curve

(Fig. 4D).

4. Create the faciall y guided 2D smile frame by

using reference lines. Determine the length of the

central incisors and the incisal curve f ollowing the

lower lip in the dynamic analysis of the facial video

(Fig. 5A).

17-19

Then, the app simulates an initial

proposal of a 2D smile. A library containing different

shapes of teeth with natural morphology and texture

is used to create t he desired result (Fig. 5B, 5C).

Mark the lower border of t he upper lip to simulate

the design under the lips effect (Fig. 5D). Use the

software’s before and after comparison tool to

virtually show the patient the expected result and

communicate the treatment wishes and expectations

(Fig. 5E).

5. Perform the 3D digital wax pattern st arting on

the 4 views screening to adjust the position of the

teeth for a motivational trial restoration design

(Fig. 6A, 6B). Superimpose the facial and IOS STL to

evaluate the harmony of the 3D virtual wax pattern

with the face (Fig. 6C). Use the Sculpt tool to add,

remove, or modify the tooth mesh according to the

smile frame (Fig. 6D) follow ing the harmon y of the

facial scan ﬁle. Export the template STL ﬁle to a

chairside 3D printer (Fig. 6 E).

6. Manufacture the r esin t emplates with a stereo-

lithography process (remove the 3D printing support,

Table 1. Comparison between outsourced 2-appointment workﬂows

and chairside 1-appointment workﬂow

Outsourced 2-Appointment

Workﬂow

Chairside One-Appointment

Workﬂow

Estimated

Time*

Estimated

Time*

Five facial photographs/no

video+impression+cast

scanning in the laboratory

20 Facial scan+1

photograph+1 facial

video with smile

dynamics+IOS

Two-dimensional smile

simulation in keynote/

power point

25 Automated 2D smile

simulation in app

supported by AI

technology

Export 2D ﬁles to a 3D

CAD laboratory software

program

5 Two-dimensional/3D

ﬁles automatically

integrated in app

Three-dimensional smile

design in a CAD laboratory

software program

20 Intuitive chair-side 3D

smile design

Three-dimensionally

printed cast in laboratory

20 Three-dimensionally

printed resin templates

in ofﬁce

Silicone index+bisacryl

resin trial restoration

(setting, removing excess,

adjustments)

15 Shells trial restoration

templates

0.5

Total 105 Total 70.5

*In minutes.

Figure 1. A, Outsourced workﬂow: I) photographs and impression; II)

cast scanning, 2D smile simulation in presentation software, 3D smile

design in CAD software, 3D printed cast; III) silicone index,

autopolymerizing resin trial restoration. B, Chairside workﬂow: I) facial

scan, video recording of smile dynamics, intraoral maxillary scanning; II)

2D or 3D smile design in same app with automatic link, 3D printed

templates; III) snap-on resin template trial restoration. CAD, computer-

aided design.

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Figure 2. A, Patient ﬁles can be saved on app. B, Autocapture and reference lines for best positioning. C, Photograph made and incorporated into

documentation. D, Video made with app. E, F, Scanning face process inside of app. G, Facial scan added to documentation. H, I, Adding maxillary STL

ﬁle directly from scanner. J, IO STL scan added to documentation. STL, standard tessellation language.

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wash, and polymerize) (Fig. 7A). Insert the resin

templates with drops of ﬂowable composite resin and

light-polymerize to create a snap-on trial restoration.

Record and make pictures of the patient with the trial

restoration and create a presentation on the DSDApp

adding photographs, videos, and ﬁles from the smile

simulation and 3D design to show and motivate the

patient (Fig. 7B-D).

DISCUSSION

Currently, one of the biggest challenges with digital

dentistry is to store and organize ﬁles from different

ﬁles formats. The present article describes how to

gather all digital information from different devices by

using only one mobile app. With patient digitalization

and cloud dentistry, all the discussions, solutions, and

decisions can be performed online, in an asynchronous

way, allowing the team to communicate at anytime and

anywhere.

According to the reported technique, the complete

patient documentation and design ﬁles can be easily

opened on a cell phone and shared with the pro-

fessional team involved in the interdisciplinary

facially driven treatment planning. Additionally, ﬁles

can be exported to other devices without the need

for an additional software program, making the

DSDApp a reliable and low-cost solution for dental

ofﬁces.

Adding to the improved patient digitalization pro-

cess, DSDApp 3D can be used in 2 different stages of

treatment. The ﬁrst stage is before treatment accep-

tance. The app is used to simulate a smile and make a

trial restoration, communicate with the patient, create

a link, and motivate the patient to understand the

beneﬁts of a better smile. At the second stage, during

the restorative treatment, the app is used for a new 2D

simulation and 3D technical trial restoration following

the initial design plan, such as to adjust the shape and

contour of deﬁnitive restorations, reducing the time for

adjustments in the clinical evaluation appointment. It

brings high predictabili ty from initial plannin g until

delivery of restorations. The similarity between digital

Figure 3. Calibration (screen shot). A, Menu screen to start new project.

B, Patient documentation open. C, STL position calibration. D, STL virtual

pivot positioning. STL, standard tessellation language.

Figure 4. A, Facial reference lines (interpupillary, commissure lines, and

facial midline) enables rotation and adjustment of photograph. B, Facial

ﬂow analysis automated in app. C, Superimposition of facial STL,

D. Determine new occlusal curve. STL, standard tessellation language.

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and trial restoration ﬁles and t he deﬁnitive restorations

shows the predictability that can be achieved through

the concept termed “Copy/Paste Dentistry”.Theﬁles

generated in the app can be opened by using any CAD

software program to continue the restorative process

with predictability.

A further advantage provided by the app is to use

video recording during the 3D virtual wax pattern to

guide the smile d esign process. By using th is tool,

the accuracy of treatment planning can be increased

by capturing the dynamic smile. Considering that the

patient’s smile may not be spontaneous in photo-

graphs, the dynamic smile captured in video

recording is more r ealistic and may be helpful in

deﬁning the patient’s actual needs, especially for

complex rehabilit ations.

With the high quality of

today’s cell phones, it provides a great tool for

making the video, frontal photograph , and facial

scan, all with one device. A cell phone with the facial

recognition feature allows the facial scan to be made

Figure 5. Two-dimensional smile simulation (screen shot). A, Facially guided smile frame in dynamic analysis visualizing treatment ﬁles

and videos. B, Desired result based on smile donator template. C, Facial veriﬁcationofproposeddesign.D,Markingupperlip.E,Beforeand

after smile simulation in 2D.

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and excludes the need for different photograph an-

gles as it can be rotated for evaluation during 3D

smile design.

Intraoral scans generate 3D images with excellent

color, removing the need for intraoral photography for

treatment planning. Therefore, as demonstrated in this

article, a full facially driven smile can be designed with

4 ﬁles: a frontal smiling photograph, a video, a facial

scan, and an IO scan. Moreover, the resin templates

can be p rinted chairside to f abricate a t rial restoration.

This approach allows the virtual treatment plan and

the clinical evaluation to be performed in the same

appointment (Table 1).

The limitations include that the trial restorations are

not appropriated for patien ts with extensive horizontal or

vertical overlap because trial restorations require an ad-

ditive approach. Additionally, integration of the

mandibular arch STL ﬁle to evaluate occlusion is not

available with the present version, restricting the use of

the app for planning occ lusal rehabilitations.

Figure 6. Three-dimensional smile design (screen shot). A, Four views in 3D. B, Dynamic view for detailed 3D design. C, Superimposition of facial STL

and maxillary STL ﬁle with 3D smile design. D, Digital wax pattern using Sculpt tool (tooth structure added, removed, and changed according to smile

frame). E, Shell STL ﬁle exported to chairside 3D printer. STL, standard tessellation language.

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SUMMARY

The new DSDApp 3D is a straightforward and versatile

tool for performing digital planning in dental practice. As

it does not require any com plex softwa re program, the

clinician can easily use it by means of a mobile device,

reducing costs, minimizing the learning curve, and saving

time. For clinicians who wish to augment the smile

analysis, the app can also be used in com bination with

other digital technologies. In addition, esthetic planning

can be optimized by scanning the face and the mouth,

making a facial video with smile dynamics, designing the

3D smile in the app, print ing the resin templates, and

performing the clinical trial in the same appointment.

REFERENCES

1. Zanardi PR, Zanardi RLR, Stegun RC, Sesma N, Costa BN, Lagana DC. The

use of the digital smile design concept as an auxiliary tool in aesthetic

rehabilitation: a case report. Open Dent J 2016;10:28-34.

2. Coachman C, Calamita MA, Coachman FG, Coachman RG, Sesma N.

Facially generated and cephalometric guided 3D digital design for complete

mouth implant rehabilitation: a clinical report. J Prosthet Dent 2017;117:

577-86.

3. Coachman C, Calamita MA, Sesma N. Dynamic documentation of the smile

and the 2d/3d digital smile design process. Int J Periodontics Restorative Dent

2017;37:183-93.

4. Edelhoff D, Probst F, Ehrenfeld M, Prandtner O, Schweiger J,

Liebermann A. Interdiscipl inary full-mouth rehabilitation for redeﬁning

esthetics, function, and orofacial harmony. J Esthet Restor Dent 2019;31:

179-89.

5. Davis NC. Smile design. Dent Clin North Am 2007;51:299-318.

6. Calamia JR, Levine JB, Lipp M, Cisneros G, Wolff MS. Smile design and

treatment planning with th e help of a comprehensive esthetic evaluation

form. Dent Clin North Am 2011;55:187-209.

7. Zimmermann M, Mehl A. Virtual smile design systems: a current review. Int J

Comput Dent 2015;18:303-17.

8. Joda T, Ferrari M, Gallucci GO, Wittneben JG, Bragger U. Digital technology

in ﬁxed implant prosthodontics. Periodontol 2000 2017;73:178-92.

9. Meereis CT, de Souza GB, Albino LG, Ogliari FA, Piva E, Lima GS. Digital

smile design for computer-assisted esthetic rehabilitation: two-year follow-

up. Oper Dent 2016;41:e13-22.

10. Joda T, Bragger U, Gallucci GO. Systematic literature review of digital three-

dimensional superimposition techniques to create virtual dental patients. Int J

Oral Maxillofac Implants 2015;30:330-7.

11. Joda T, Gallucci GO. The virtual patient in dental medicine. Clin Oral Im-

plants Res 2015;26:725-6.

12. Bohner L, Gamba DD, Hanisch M, Marcio BS, Tortamano Neto P,

Lagana DC, et al. Accuracy of digital technologies for the scanning of facial,

skeletal, and intraoral tissues: a systematic review. J Prosthet Dent 2018;121:

246-51.

13. Kano P, Xavier C, Ferencz JL, Van Dooren E, Silva N. The anatomical shell

technique: an approach to improve the esthetic predictability of CAD/CAM

restorations. Quintessence Dent Technol 2013;36:27-36.

14. Kano P, Baratieri L, Decúrcio R, Duarte S Jr, Saito P, Ferencz JL, et al. The

anatomical shell technique: mimicking nature. Quintessence Dent Technol

2014;37:96-112.

15. Heller M, Bauer HK, Goetze E, Gielisch M, Roth KE, Drees P, et al. Appli-

cations of patient-speciﬁc 3D printing in medicine. Int J Comput Dent

2016;19:323-39.

16. Barazanchi A, Li KC, Al-Amleh B, Lyons K, Waddell JN. Additive technology:

Update on current materials and applications in dentistry. J Prosthodont

2017;26:156-63.

17. McLaren EA, Garber DA, Figueira J. The Photoshop Smile Design technique

(part 1): digital dental photography. Compend Contin Educ Dent 2013;34.

772, 774, 776 passim.

18. Sousa Dias N, Tsingene F. S AEF - Smile’ s Aesthetic Evaluation form: a

useful tool to improve communications between clinicians and

patients during multidisciplina ry treatment. Eur J Esthet Dent 2011;6:

160-76.

19. Coachman C, Calamita MA. Digital Smile Design: a tool for treatment

planning and communication in esthetic dentistry. Quintessence Dent

Technol 2012;35:103-11.

Corresponding author:

Dr Lauren Bohner

Department of Prosthodontics

University of São Paulo

Av. Prof. Lineu Prestes 2227-Cidade Universitária

São Paulo

BRAZIL

Email: [email protected]

Acknowledgments

The authors thank Sergio Saraiva, Angelo Rafael, Ricardo Kimura, Carla de

Castro, and DSD Planning Center for the collaboration in this article.

https://doi.org/10.1016/j.prosdent.2019. 10.015

Figure 7. A, Clinical evaluation with trial restoration showing 3D printed

facial templates. B, Presentation ﬁles and photographs and videos of trial

restoration added to app to create presentation. C, D, Presentation.

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