Surgical and Restorative Aid of 3D Printed Models for Implant Placement
A Case Presentation
Tatiana Pashkova, DDSc • Arshin Hotchandani, BDS, MDS • Aikaterini Georgantza, DDS • Takanori Suzuki, DDS, PhD • Yung Cheng Paul Yu • Sang-Choon Cho, DDS
of bone occurs once a tooth is extracted and the socket is allowed to heal.1
In the maxilla, change in the width of
bone is more than the change in the height.2 Oftentimes extraction
of upper premolar teeth leads to formation of a buccal concavity around the
apical area. The presence of this concavity may go undiagnosed clinically due
to the thickness of the soft tissues covering it. It becomes necessary to
change the angulation of the future implant in such sites in order to keep it
inside the bony housing and avoid guided bone regeneration procedures.
Conventional cone beam computed tomography (CBCT) technology has been utilized
to evaluate the available bone in these sites. However, it can be difficult to
extrapolate the two dimensional CBCT image to three dimensional extent of the
bony defect, making surgical planning stressful. Therefore, 3D printing
technology has been introduced as a fast and cost effective tool for surgical
planning and practice. Three-dimensional printed models help to plan and
visualize the available bone in the proposed implant site and allows for
simulation of osteotomy.
(SLA) models, which were first used by Hull in 1988 in the field of medicine,3
can be extrapolated for use in implant dentistry and surgical implant planning
as well. With the help of these models, it is possible to reduce surgical time,
limit the amount of soft tissue manipulation, and decrease the potential for
error in implant placement.4 Three-dimensional printed models can be
useful for preoperative simulation of the surgical site. Additionally, SLA models
can improve surgical planning and act as an aid during surgery.5
aim of this case report is to focus on how a presurgical
3D printed model can be a valuable aid for implant planning and placement.
37-year-old female patient presented to the Ashman Department of Periodontology
and Implant Dentistry at New York University College of Dentistry for
replacement of a missing premolar tooth #13, which had been extracted over 9
months ago. Intraoral site evaluation and periapical radiographs, made using
the paralleling cone technique, confirmed the presence of healthy and adequate
available bone (i.e., both apicocoronally and mesiodistally) for implant
placement. (Figures 1 and 2).
diagnostic impression was made pre-operatively, and a pre-surgical wax up was
performed on a model to plan prosthetically driven implant placement. This was
also used to fabricate a radiographic guide and a surgical guide so as to
position the screw access hole through the central fossa of the definitive restoration
Imaging and Communications in Medicine (DICOM) images from the patient’s
CBCT scan were then converted to STL files (OsiriX Lite, Geneva, Switzerland)
and transferred to a 3D printer for production of a polymer model of the maxilla.
On the 3D printed model, ideal osteotomy was prepared according to the surgical
guide. Mock surgical placement of the implant was attempted first by drilling
an osteotomy straight through the site in the model (Figures 4 and 5). This,
however, led to the exposure of the apical portion of the implant and its
emergence through the bony housing, which would have required guided bone
regeneration (GBR) to cover the exposed implant. By simply redirecting the
osteotomy more towards the palatal aspect, however (Figures 6 and 7), the
fenestration could be avoided while still ensuring the optimal location of the
screw access hole. The surgical guide was modified to correct the angulation
and surgery was performed using sequential drills according to the manufacturer’s
instructions. The implant was placed in the osteotomy and the flaps were closed
to achieve primary closure.
allowing the implant to osseointegrate, the implant was uncovered during the
second stage surgery. This was followed by placement of a healing abutment.
Once the soft tissues healed, open-tray impression technique was used to make a
fixture level impression using polyether impression material (Impregum, 3M Espe,
St. Paul, MN). A master cast was then prepared (Resin Rock, Whipmix Corp., Louisville,
KY) on which a screw-retained restoration was fabricated according to the
diagnostic wax-up. The final restoration was seated and occlusion was checked. The
fit of the restoration was verified using radiographs. It was then torqued into
place according to the manufacturer’s recommendation. The 1-year followup
of the restoration showed healthy integration of the implant and the
restoration with the surrounding soft and hard tissues (Figures 8, 9, 10, 11, and 12).
conventional imaging does provide adequate information, 3D printed models help
the clinician to physically appreciate the bone contour in the area of the
missing tooth. Lambrecht
and colleagues described the use of haptic models for educational purposes.6
The word Haptic is derived from the Greek word “Haptikos” meaning “to contact or to touch”.
They proposed that 3D prototype CBCT-based haptic models can help students
simulate advanced surgical cases before performing them in the patient. This
provides the operator with greater precision and ability to redirect the
osteotomy angulation such that fenestration of the implant apex can be avoided
while still allowing the operator to fabricate a screw-retained prosthesis with
the screw access hole emerging through the center of the restoration, thus
fulfilling multiple treatment goals.
printed models have revolutionized treatment planning in implant dentistry. In
the era or minimally invasive surgery and flapless surgery, where a primary
objective is to preserve the soft tissue and minimize its manipulation, 3D
printed models can support a prototype surgery to ensure precise implant
placement without the need to reflect a full-thickness mucoperiosteal flap. A
replica of the anatomical structures of the maxilla and the mandible including
the bone and the surrounding tissues as well as intrabony landmarks (e.g., the
maxillary sinuses and the location of the inferior alveolar nerve as well as
the mental foramen) can be precisely replicated on the model; the violation of which
can be avoided during surgery.7 Additionally, models can be used as
a scaffold to determine the amount of graft material required for GBR and help
predetermine the volume of bone substitutes necessary for a particular site.
They can also prove invaluable by saving chair time often required for trimming
and contouring of non-resorbable membranes such as titanium mesh or collagen
membranes.4 The applications of using 3D printed models are evolving
and can be applied to multiple implant surgical planning and restorative. These
printers are now being used to print temporary crowns and bridges.
Pre-fabricated screw-retained multiunit implant restorations for immediate
provisionalization post-surgery can also be prepared.8
3D printed models with the corrected angulations could also be used to
fabricate a new surgical guide to ensure proper apico-coronal and facio-lingual
implant placement. This
mock surgery helps the surgeon to replicate the implant placement in the
correct position in the patient and to obtain a satisfactory surgical and
prosthetic outcome in a predictable manner (Figures 8, 9, 10, 11, and 12). The
advantage of performing the procedure in vitro is reduced operating time and
the cost and the time involved in computer-aided design / computer-aided
manufacturing (CAD/CAM) of laboratory-fabricated surgical guides and models,
models fabricated by the 3D technique are more economical. The amount of time
required for their fabrication is reduced, as multiple models of varying
dimensions can be simultaneously printed compared to CAD/CAM guides, which
generally consume an entire blank of acrylic resin for fabrication and require
a long milling cycles.
aim is to use these models routinely in basic and advanced implant education.
Surgical education with models, using data from patients, provides a method of
teaching and has a long tradition in conservative operative dentistry. Specific
areas of use in implant dentistry regarding 3D printing and modeling include:
teaching of anatomic structures,
treatment planning and preoperative practicing, and
simulating prostheses and maintenance education.
options for processing the datasets and producing the models will need to be
studied. Mass production of these models can make it possible for use in all
implant education programs. The students will be able to better develop their
visual and hand-eye co-ordination skills with the help of these models and
grasp the concepts of surgery easily.10
3D models based on CBCT datasets has great potential for implant education,
particularly for understanding, planning, and surgical practice. A more
exciting prospect is the printing and patterning of all the components that
make up a tissue (i.e., cells and matrix materials) to generate tissue analog
structures; this has been termed “bioprinting”.11
use of 3D printed models act as a surgical and restorative aid for dental
implants. They help us to plan, correct, and restore implants as influenced by
the anatomy of the bone. It helps to minimize the surgical errors and the time
of surgery as well as to achieve prosthetically driven implant placement. A 3D
printed model serves as a guide to the optimal prosthetic outcome in terms of
esthetics, occlusion and achieving the screw-access hole in an ideal location.
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