DENTAL TECHNIQUE

Three-dimensional printing in contemporary fixed

prosthodontics: A technique article
Sarah Bukhari, BDS,a Brian J. Goodacre, DDS, MSD,b Abdulaziz AlHelal, BDS, MS, FACP,c
Mathew T. Kattadiyil, BDS, MDS, MS,d and Paul M. Richardson, CDTe

The wide adoption of digital ABSTRACT

dentistry and dental technology
Digital dentistry has gained in popularity among clinicians and laboratory technicians because of its
has been rapid.1-4 Computer- versatile applications. Three-dimensional (3D) printing has been applied in many areas of dentistry
aided design and computer- as it offers efficiency, affordability, accessibility, reproducibility, speed, and accuracy. This article
aided manufacturing (CAD- describes a technique where 3D printing is used to fabricate a die-trimmed cast and to replicate
CAM) has been successfully gingival tissue and implant analogs. The digital workflow that replaces the conventional laboratory
used in both removable and procedure is outlined. (J Prosthet Dent 2018;119:530-4)
fixed prosthodontics,5-7 and
3-dimensional (3D) printing has been an area of digital combination of natural tooth preparation dies, implant
technology growth.2,8 restoration dies, and the soft tissue profile in a single
Three-dimensional printing or rapid prototyping printable cast.
technology has been extensively used in the industrial,
engineering, and medical fields, enabling manufacturers
to fabricate parts and end products.8 Furthermore, rapid
prototyping has been used in different fields of dentistry,
including surgical planning,8 fabricating maxillofacial
prostheses,9 making fixed and removable dental pros-
thodontics,2,10,11 orthodontics,12and implant dentistry.13
Advances in this technology will have a great impact
on dentistry.
Affordable desktop 3D printers along with user-
friendly 3D software provide opportunities for the use
of polymer-based 3D-printed materials across all aspects
of dentistry.14-22 They enable the in-office printing of
diagnostic casts, teaching aids, die-trimmed casts of
prepared teeth, and surgical guides.13-16 Figure 1. Virtual die-trimmed cast designed with contemporary fixed
This report introduces the use of 3D printing tech- prosthodontics approach, including designing tooth preparation dies,
nology to replace the conventional fixed prosthodontic implant analogs, and soft tissue emergence profile replica for both
laboratory process. This includes the reproduction of a implant abutments and pontic areas.

a
Graduate student, Advanced Specialty Education Program in Prosthodontics, School of Dentistry, Loma Linda University School of Dentistry, Loma Linda, Calif.
b
Assistant Professor, School of Dentistry, Loma Linda University, Loma Linda, Calif.
c
Faculty, Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
d
Professor and Director, Advanced Specialty Education Program in Prosthodontics, Loma Linda University School of Dentistry, Loma Linda, Calif.
e
Certified Dental Technician, Loma Linda University School of Dentistry, Loma Linda, Calif.

530 THE JOURNAL OF PROSTHETIC DENTISTRY

April 2018 531

Figure 2. A, Gingival tissue insert printed from flexible resin. B, Printed

cast with dies, gingival tissue insert, and implant analogs.

TECHNIQUE
A technique for fabricating both implant- and tooth-
supported interim or definitive restorations follows:
1. Prepare the teeth and place gingival displacement
cord.
2. Remove healing abutments on implants and
immediately perform the intraoral scan (TRIOS 3
Mono Intraoral Scanner; 3Shape). Record a scan of
the opposing arch along with an occlusal
registration. Figure 3. A, Occlusal view of printed cast showing die spaces in maxil-
3. Place scan bodies (NC Straumann, CARES, Mono lary left canine and first premolar tooth areas. B, Lateral view of printed
Scanbody; Straumann) on the implants and record cast showing printed dies. C, Occlusal view of printed cast showing
a second intraoral scan. seated dies.
4. Import recorded scans into CAD software (Dental
System; 3Shape), transferring information on
implant location, tooth preparations, soft-tissue created (Fig. 1). The designed restorations with
volume, and occlusion. appropriate emergence profile and/or pontic
5. Using CAD software (Dental System; 3Shape), shapes are transferred to the cast.
design appropriate emergence profile and crown 7. Cut the cast digitally at the level of the implant
anatomy. platform to create a soft tissue insert (Fig. 1).
6. Transfer restoration design into the cast design 8. Export the maxillary and mandibular casts, dies,
software (Model Builder; 3Shape). A combined die and gingival tissue as standard tessellation lan-
and cast with integrated implant analogs is then guage files (Fig. 1).

Bukhari et al THE JOURNAL OF PROSTHETIC DENTISTRY

532 Volume 119 Issue 4

Figure 4. A, Occlusal view of printed cast showing implant analog spaces in areas of maxillary right and left lateral incisors. B, Occlusal view of printed
cast showing gingival tissue insert, implant analogs, and die spaces. C, Virtually mounted maxillary and mandibular casts. D, Frontal view of mounted
printed maxillary and mandibular casts.

9. Fabricate the maxillary and mandibular casts along 15. Cement the titanium bases to the milled interim
with dies by using a 3D printer (Form 2; Formlabs). restorations with resin cement (Panavia F 2.0;
Print the casts and the dies by using Formlabs Kuraray America Inc) (Fig. 5A).
standard gray resin. 16. Seat the interim restorations intraorally to evaluate
10. Print the gingival tissue insert separately on the esthetics and function (Fig. 5B).
same printer by using Formlabs flexible resin 17. Following trial placement of the interim restora-
(Fig. 2A). tions and patient acceptance, the definitive resto-
11. Clean and prepare the printed components for rations can be fabricated using a similar digital
assembly (Fig. 2B). A special type of implant analog protocol (Fig. 6).
is used for the printed cast (Impression analog
model Str NC; Core 3D Centres).
DISCUSSION
12. Mill the designed restorations (Roland DWX-50;
Whip Mix Corp) from a poly(methylmethacrylate) A technique for fabricating a 3D die-trimmed cast for
(PMMA) blank (Telio CAD; Ivoclar Vivadent AG) natural teeth and implant restorations, maintaining soft
of the appropriate shade. tissue profile around both types of restorative abutments,
13. Assemble the printed cast with dies (Fig. 3), implant is presented. The technique allows for better visualization
analogs, and gingival tissue insert (Fig. 4A, B) and and design of the restorative emergence profile. Desktop
mount the casts on an articulator (Fig. 4C, D). 3D printers usually use a liquid photopolymerizing resin
14. Attach titanium bases to the implant analogs composed of methacrylate acid esters, acrylic acid esters,
and then evaluate the milled interim restorations and photo-initiators that harden upon exposure to ul-
on the titanium bases. Adjust the proximal and traviolet light. This material provides casts that are ac-
occlusal contacts as needed. curate,17,18 lightweight, dense,16 and resistant to wear

THE JOURNAL OF PROSTHETIC DENTISTRY Bukhari et al

April 2018 533

Figure 6. Definitive restoration on printed cast. A, Right lateral view. B,

Left lateral view.

significant amount of wasted material.19 Furthermore,

advanced industrial printers provide the ability to print
multiple different materials simultaneously. Three-
dimensional printing technology has been successfully
used to print wax patterns for metal framework casting,
removable partial denture metal frameworks, and metal
prostheses.10,20,21 The main advantages of this technol-
ogy are reduced labor costs, reduced fabrication errors,
and increased production efficiency.16
The lower cost of the consumer grade 3D printers16
Figure 5. A, Frontal view of interim restoration seated on printed cast. and the ability to incorporate this technology into clin-
B, Frontal view of interim restoration seated in patient mouth. C, Intraoral ical practice have appealed to many clinicians, who
frontal view showing soft tissue contour after 2 months of healing. mostly use them to print casts and surgical
guides.13,14,16,18 Printed casts can also be used for treat-
and damage during restoration fabrication. In addition, ment planning and to rehearse surgical procedures.8,22
the ability to store these data in a digital format elimi- The learning curve for the CAD software, the high
nates the need for the physical storage space associated initial cost of purchasing and licensing CAD software
with conventional casts. Should a physical cast be along with the printer, production time, available print-
needed, it can be rapidly fabricated with the same pre- able materials, and post-processing procedures still limit
cision and quality as the original cast.10 the use of 3D printers in a dental office. The higher the
An alternative to 3D printing is computer numerical accuracy the smaller the vertical resolution used for the
controlled (CNC) milling. However, the drawbacks of printed part, increasing the number of printed layers and
CNC milling include difficulties in creating complex ge- thus the time required to print the cast.18 Developing a
ometries and accurate reproduction of undercuts and the biocompatible, printable material with the desired dental

Bukhari et al THE JOURNAL OF PROSTHETIC DENTISTRY

534 Volume 119 Issue 4

properties remains a challenge. The current US Food and 8. Malik HH, Darwood AR, Shaunak S, Kulatilake P, El-Hilly AA, Mulki O,
Baskaradas A. Three-dimensional printing in surgery: a review of current
Drug Administration-approved printable materials are surgical applications. J Surg Res 2015;199:512-22.
limited in type and color. In the presented technique, a 9. Jindal SK, Sherriff M, Waters MG, Coward TJ. Development of a 3D printable
maxillofacial silicone: Part I. Optimization of polydimethylsiloxane chains and
dark-shade resin was used to print both the soft tissue cross-linker concentration. J Prosthet Dent 2016;116:617-22.
insert and the cast. Recently Formlabs introduced a new 10. Sun J, Zhang FQ. The application of rapid prototyping in prosthodontics.
J Prosthodont 2012;21:641-4.
amber-colored resin for casts. Another pink flexible resin 11. Kurahashi K, Matsuda T, Goto T, Ishida Y, Ito T, Ichikawa T. Duplication of
material for printing the soft tissue inserts (Next Dent complete dentures using general-purpose handheld optical scanner and 3-
dimensional printer: introduction and clinical considerations. J Prosthodont
Gingiva Mask; Next Dent) is available but was not Res 2017;61:81-6.
compatible with the 3D printer (Form2; Formlabs) used 12. Gracco A, Mazzoli A, Raffaeli R, Germani M. Evaluation of 3D technologies
in dentistry. Prog Orthod 2008;9:26-37.
in this report. 13. Di Giacomo GA, Cury PR, de Araujo NS, Sendyk WR, Sendyk CL. Clinical
application of stereolithographic surgical guides for implant placement:
preliminary results. J Periodontol 2005;76:503-7.
SUMMARY 14. Ayoub AF, Rehab M, O’Neil M, Khambay B, Ju X, Barbenel J, et al. A novel
approach for planning orthognathic surgery: the integration of dental casts
Rapid advances in 3D printing technology will certainly into three-dimensional printed mandibular models. Int J Oral Maxillofac Surg
2014;43:454-9.
further influence many aspects of traditional dentistry. 15. Soares PV, de Almeida Milito G, Pereira FA, Reis BR, Soares CJ, de Sousa
The capabilities and usefulness of 3D printing in pros- Menezes M, et al. Rapid prototyping and 3D-virtual models for operative
dentistry education in Brazil. J Dent Educ 2013;77:358-63.
thetic dentistry has yet to be fully studied and developed. 16. Scherer MD. A contemporary approach to intraoral optical scanning and in-
This technique article provides an example of the use of office 3-D printing. Dent Today 2015;34:46-7.
17. Hazeveld A. Accuracy and reproducibility of dental replica models recon-
3D printing to create a definitive cast. structed by different rapid prototyping techniques. Am J Orthod Dentofacial
Orthop 2014;145:108-15.
18. Kasparova M, Grafova L, Dvorak P, Dostalova T, Prochazka A, Eliasova H,
REFERENCES et al. Possibility of reconstruction of dental plaster cast from 3D digital study
models. Biomed Eng Online 2013;12:49.
1. AlHelal A, Jekki R, Richardson PM, Kattadiyil MT. Application of digital 19. Van Noort R. The future of dental devices is digital. Dent Mater 2012;28:3-12.
technology in the prosthodontic management of a myasthenia gravis patient: 20. Cho SH, Chang WG. Mirror-image anterior crown fabrication with
a clinical report. J Prosthet Dent 2016;115:531-6. computer-aided design and rapid prototyping technology: a clinical report.
2. Bilgin MS, Erdem A, Aglarci OS, Dilber E. Fabricating complete dentures with J Prosthet Dent 2013;109:75-8.
CAD/CAM and RP technologies. J Prosthodont 2015;24:576-9. 21. Kattadiyil MT, Mursic Z, AlRumaih H, Goodacre CJ. Intraoral scanning of
3. Kattadiyil MT, Jekki R, Goodacre CJ, Baba NZ. Comparison of treatment hard and soft tissues for partial removable dental prosthesis fabrication.
outcomes in digital and conventional complete removable dental prosthesis J Prosthet Dent 2014;112:444-8.
fabrications in a predoctoral setting. J Prosthet Dent 2015;114:818-25. 22. Martelli N, Serrano C, Van Den H, Pineau J, Prognon P, Borget I, et al.
4. AlHelal A, AlRumaih H, Kattadiyil MT, Baba NZ, Goodacre CJ. Comparison Advantages and disadvantages of 3-dimensional printing in surgery: a sys-
of retention between maxillary milled and conventional denture bases: a tematic review. Surgery 2016;159:1485-500.
clinical study. J Prosthet Dent 2017;117:233-8.
5. Kattadiyil MT, AlHelal A. An update on computer-engineered complete
dentures: a systematic review on clinical outcomes. J Prosthet Dent 2017;117: Corresponding author:
478-85. Dr Sarah Bukhari
6. AlHelal A, AlBader B, Kattadiyil MT, Garbacea A, Proussaefs P. CAD-CAM Loma Linda University, School of Dentistry
implant-supported fixed complete dental prosthesis with titanium milled 11092 Anderson St
molars: a clinical report. J Prosthet Dent 2017;117:463-9. Loma Linda, CA 92350
7. Paniz G, Stellini E, Meneghello R, Cerardi A, Gobbato EA, Bressan E. The Email: sbukari@llu.edu
precision of fit of cast and milled full-arch implant-supported restorations. Int
J Oral Maxillofac Implant 2013;28:687-93. Copyright © 2017 by the Editorial Council for The Journal of Prosthetic Dentistry.

THE JOURNAL OF PROSTHETIC DENTISTRY Bukhari et al