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Computer-Guided Implant Dentistry for Precise Implant Placement: Combining Specialized Stereolithographically Generated Drilling Guides and Surgical Implant Instrumentation

June 2010
The International journal of periodontics & restorative dentistry 30(3):275-81

Source
PubMed

Authors:

George A Mandelaris

University of Illinois Chicago

Marc Nevins

Harvard University

The application of computed tomography (CT) and the use of computer software for dental implant therapy have significantly increased during the last several years. Dental implant positioning can be either "partially guided," where only osteotomy sites are prepared using sequential, removable surgical drilling guides (generated using computer software and through the process of stereolithography), or "totally guided," whereby one guide is used for osteotomy site preparation as well as implant delivery. Recently, the guided delivery of manufacturer-specific internal-connection implants has become available. Individualized protocols and specific instrumentation are employed under this approach to CT-based implant surgery. The purpose of this article is to expand on previous publications related to the use of prosthetically directed implant placement using computer software to ensure precise placement and predictable prosthetic outcomes. Three case reports are presented where precision-guided CT-based surgery was employed and the immediate delivery of a dental prosthesis was facilitated.

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The International Journal of Periodontics & Restorative Dentistry

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The advent and growing popularity of

in-office cone beam computed tomog-

raphy (CT) scanners as well as the avail-

ability of imaging centers has improved

diagnostics for dentistry as a whole.

With its growing awareness and pop-

ularity in three-dimensional (3D) tech-

nology, implant companies are now

incorporating CT-based guided implant

dentistry into their armamentariums for

clinicians.1The role of computer-guided

implant dentistry is expanding to offer

the delivery of specific implants into

presurgically determined prosthetic

positions in all three planes of space:

buccolingual, mesiodistal, and apico-

coronal. In addition, the opportunity

for an immediately loaded prosthesis

or an immediate–nonocclusal load

prosthesis can be facilitated by such

opportunities and protocols.2–5

The purpose of this article is to

expand on previous publications

related to computer-guided implant

dentistry by relating the concept of

precise, totally guided CT-based

surgery for internal-connection

implants. Three case reports are pre-

sented to demonstrate the applicabil-

ity and versatility of precision-guided

CT-based surgery in clinical practice.

Computer-Guided Implant Dentistry for

Precise Implant Placement: Combining

Specialized Stereolithographically

Generated Drilling Guides and Surgical

Implant Instrumentation

George A. Mandelaris, DDS, MS*

Alan L. Rosenfeld, DDS**

Samantha D. King, DMD***

Marc L. Nevins, DMD, MMSc****

The application of computed tomography (CT) and the use of computer software

for dental implant therapy have significantly increased during the last several years.

Dental implant positioning can be either “partially guided,” where only osteotomy

sites are prepared using sequential, removable surgical drilling guides (generated

using computer software and through the process of stereolithography), or “totally

guided,” whereby one guide is used for osteotomy site preparation as well as

implant delivery. Recently, the guided delivery of manufacturer-specific internal-

connection implants has become available. Individualized protocols and specific

instrumentation are employed under this approach to CT-based implant surgery.

The purpose of this article is to expand on previous publications related to the use

of prosthetically directed implant placement using computer software to ensure

precise placement and predictable prosthetic outcomes. Three case reports are

presented where precision-guided CT-based surgery was employed and the imme-

diate delivery of a dental prosthesis was facilitated. (Int J Periodontics Restorative

Dent 2010;30:275–281.)

*Private Practice, Park Ridge and Oakbrook Terrace, Illinois.

**Private Practice, Park Ridge and Oakbrook Terrace, Illinois; Clinical Professor,

Department of Graduate Periodontics, University of Illinois, College of Dentistry,

Chicago, Illinois.

***Private Practice, Boston, Massachusetts.

**** Private Practice, Boston, Massachusetts; Clinical Assistant Professor, Department of

Periodontics, Harvard School of Dental Medicine, Boston, Massachusetts.

Correspondence to: Dr George A. Mandelaris, 1875 Dempster Street, Suite 250,

Parkside Center, Lutheran General Hospital, Park Ridge, IL 60068; email:

GMandelari@aol.com.

275

Volume 30, Number 3, 2010

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CT surgical guidance

Prosthetically directed implant place-

ment using computer software to

ensure precise placement and pre-

dictable prosthetic outcomes using

rapid-prototype medical modeling

and stereolithographic drilling guides

has been described in previous publi-

cations.6–8 The initial phase of this par-

adigm shift from a traditional approach

of implant placement to one that is

“computer-guided” included either

drilling guides that were used solely for

osteotomy site preparation (ie, par-

tially guided; SurgiGuides, Materialise

Dental) or involved the use of a single

guide for both osteotomy site prepa-

ration and implant delivery (ie, totally

guided; SAFE SurgiGuide system,

Materialise Dental).

The partially guided technique

with SurgiGuides allows for a controlled

osteotomy site preparation in two

planes of space: buccolingual and

mesiodistal. In this approach, multiple

sequential drilling guides are used for

precise osteotomy site preparation.

Vertical depth is a surgical calculation

and is not controlled. The drilling

guides are removed for countersinking

(if necessary) and implant placement is

performed using the traditional

nonguided approach. Implant place-

ment is then performed manually at the

“computer-guided” osteotomy sites.

The SAFE SurgiGuide system is

the original totally guided implant sys-

tem, allowing for controlled osteotomy

site preparation and implant placement

in three dimensions.9Similar technol-

ogy has been adapted for use in other

commercial systems.1 SurgiGuides and

the SAFE SurgiGuide system are ver-

satile in that they can be used on either

bone, tooth, or mucosal supporting

surfaces.6–8 The proof of principle

established in the SAFE SurgiGuide

system merely required mechanical

modification to facilitate the delivery

of internal-connection implants.

Totally guided precision CT-based

surgery using the SAFE SurgiGuide

system concept allows versatility in the

supporting surface (bone, tooth,

tooth-mucosa, mucosa) but uses a sin-

gle guide for osteotomy site prepara-

tion and implant placement. Specific

cylinders are embedded within the

acrylic resin guide to accommodate

drill handles or similar components

that intimately engage the cylinders.

Osteotomy site–specific drills are then

used that have vertical stops to control

apicocoronal osteotomy site prepara-

tion. Countersinking is also controlled

and tolerances are highly precise. Drill

size and drill handle application are

chosen depending upon the specific

needs of the patient and the individu-

alized CT plan. Implant placement is

performed using specific delivery

mounts and to a controlled buccolin-

gual, mesiodistal, and apicocoronal

depth, which is set by the computer-

ized 3D plan.

Fixation of these guides can be

used to prevent displacement. The sys-

tem presented in this report includes

technology to control hex orientation.

This is possible through unique align-

ment grooves that are positioned

within the guiding cylinder and at the

top of the delivery mounts. All three

patients in this report were treated

using the Navigator SurgiGuide

System (Biomet 3i and Materialise

Dental).

Patient 1

A 53-year-old man presented with

generalized advanced chronic perio -

dontitis and gross dental caries asso-

ciated with his mandibular dentition. A

strategy to transition the patient’s nat-

ural dentition to an implant-supported

prosthesis was developed. As part of

the interdisciplinary work-up, mounted

maxillomandibular casts were

obtained and a new maxillary denture

was fabricated. The existing mandibu-

lar teeth were determined to be in

nearly optimal positions compared to

the plan for a fixed implant-supported

metal-ceramic prosthesis. Because of

this unique situation, no scanning

appliance was needed and his existing

teeth were used as the optimal final

tooth positions. The patient was

referred for CT scan imaging of the

mandible with the appropriate masks,

which were transferred into a dental

implant-planning computer software

program (Sim Plant Planner, Materialise

Dental) for diagnostic and treatment

planning purposes (Fig 1a). Masks are

an important part of the processing

procedure since different object den-

sities can be manipulated to create

specialized viewing opportunities that

are critical to the treatment planning

process (Fig 1a).5Prior to surgery and

during the planning phase, control of

the patient’s periodontitis and local

inflammation was pursued via scaling

and root planing periodontal therapy.

Following intravenous conscious

sedation and delivery of local anes-

thesia, atraumatic extraction of the

remaining mandibular natural denti-

tion was performed. A full-thickness

flap reflection was performed and all

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The International Journal of Periodontics & Restorative Dentistry

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sockets were degranulated. Several

millimeters of unusable alveolar bone

were then eliminated via a stereo -

lithographically generated bone re -

duction guide. Following a precise

and guided osteoplasty, the bone-

supported Navigator SurgiGuide was

then seated to the underlying bone

surface and verified for stability and

accurate positioning. Additional sta-

bility was ensured by the placement of

three stabilization screws at preplanned

sites (Fig 1a). Totally guided osteotomy

site preparation and implant delivery

were then pursued according to the

individualized protocol for the patient

(Fig 1b). Following the delivery of

seven endosseous Nanotite Certain

(Biomet 3i) implants at preplanned

sites, the surgical guide was removed

and implant stability was verified. A

presurgically fabricated immediate-

load prosthesis was seated on the

five interforaminal implants. Following

4 months of healing, osseointegration

was confirmed, at which time one

unloaded implant (mandibular right

first molar, single-stage surgery) was

found unintegrated. The prosthetic

phase was completed with a fixed

metal-ceramic prosthesis (Figs 1c and

1d).

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Volume 30, Number 3, 2010

Fig 1a CT scan and 3D implant treatment

planning of a hopeless mandibular denti-

tion. Implants (blue) and stabilization screws

(yellow) were planned. Masks of the

mandible, remaining natural teeth, virtual

mandibular right second premolar and first

molar and left first molar, and inferior alveo-

lar nerves are present.

Fig 1b Bone-supported Navigator

SurgiGuide seated and fixated using pre-

planned stabilization screws and totally

guided implant placement in the anterior

mandible.

Figs 1c and 1d (above) Final prosthetic

outcome and (below) final radiographs of

patient 1 (Courtesy of Dr Paul Imhof, Des

Plaines, Illinois).

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Patient 2

A 44-year-old woman presented with

advanced root resorption at the max-

illary left lateral incisor (Fig 2a). The

consultation process included a treat-

ment plan for an implant-supported

restoration involving precision-based

CT-guided implant surgery and imme-

diate placement of a fixed provisional

restoration (Fig 2b).

Diagnostic study casts were

mounted. The maxillary stone cast was

retrofitted at the maxillary left lateral in -

cisor with an implant analog using the

surgical guide and allowing for the fab -

rication of a laboratory provisional crown

on an interim abutment. Under local

anesthesia, the maxillary lateral incisor

was extracted, the tooth-supported

Navigator SurgiGuide was seated, and

stability was verified, allowing for pre-

cise, flapless implant placement under

total guidance (Osseotite Certain,

Biomet 3i) (Fig 2c). Following 3 months

of uneventful healing, the final pros-

thetic phase was completed (Figs 2d

and 2e). Connective tissue grafting

was performed at the site of the max-

illary left canine for partial root cover-

age and mucogingival augmentation

at a separate surgery.

Patient 3

An 85-year-old woman presented with

a failing maxillary fixed partial denture.

After being transitioned to an interim

maxillary complete denture and allow-

ing 3 months of postextraction healing,

the patient proceeded with evaluation

for an immediate fixed provisional

prosthesis implementing precision-

based CT-guided surgery.

The appropriate esthetics, pho-

netics, occlusal stability, vertical dimen-

sion, and denture base fit were verified

with the patient’s denture. The denture

was then duplicated for fabrication of

a third-generation (Tardieu) scanning

appliance (Fig 3a).5The scanning

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The International Journal of Periodontics & Restorative Dentistry

Fig 2a (left) Preoperative presentation of

a hopeless maxillary lateral incisor.

Fig 2b (right) 2D cross-sectional view

imposed on a 3D rendering (ie, “clip art”)

for the maxillary left lateral incisor.

Fig 2c Tooth-supported Navigator

SurgiGuide in position. Flapless, totally

guided implant placement was accom-

plished. Note the unique alignment grooves

that are positioned within the guiding cylin-

der and at the top of the delivery mounts,

which enable control of the hex orientation

(arrows).

Figs 2d and 2e (above) Final prosthetic out-

come and (right) final radiograph of the

restored lateral incisor (Courtesy of Dr

Joseph Silberman, Evanston, Illinois).

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appliance was stabilized during the

imaging process via a radiolucent bite

record. Computerized treatment plan-

ning was performed using SimPlant to

determine the precise angulations and

positions for eight implants in the max-

illary arch. Four stabilization screws

were planned and incorporated into

the surgical guide for fixation during

implant placement.

A mucosa-supported Navigator

SurgiGuide was then used to create a

working cast for fabrication of the pro-

visional maxillary fixed partial denture

by inserting implant analogs attached

to specific laboratory delivery mounts

into the guide using the Navigator

prosthetic kit. A soft tissue masque

guide on the maxilla with the surgical

bite record and then fixating it with four

stabilization screws. The implant sites

were then prepared via the Navigator

SurgiGuide and its individualized pro-

tocol for the patient (Figs 3b and 3c).

Following implant placement, eight

custom and presurgically created abut-

ments were delivered using a posi-

tioning jig and hand tightened into

place. The fit and occlusion of the cross-

arch provisional were verified as being

accurate and consistent with what had

been planned. The provisional was

then cemented using temporary

cement. At 6 months postsurgery, treat-

ment began for the definitive metal-

ceramic prosthesis (Figs 3d and 3e).

was syringed around the analogs and

silicone lubricant placed on the remain-

der of the surgical guide before pour-

ing in an accurate dental stone, which

served as the working cast. The work-

ing cast was mounted on an articula-

tor oppos ing the cast of the

mandibular arch by placing the radi-

ographic template on the working cast

with the corresponding bite record.

This bite record was then transferred to

the surgical guide to create a surgical

bite record. The fit of this surgical bite

record and guide was confirmed clin-

ically before surgery.

Implant surgery was performed

under local anesthesia. Treatment was

initiated by positioning the surgical

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Volume 30, Number 3, 2010

Fig3a Mounted differential barium gradi-

ent scanning appliance in position with the

bite registration (pink).

Fig 3b Totally guided, flapless osteotomy

site preparation was completed and implant

delivery accomplished via a mucosa-

supported Navigator SurgiGuide.

Fig3c Totally guided, flapless implant

placement was completed and the

Navigator SurgiGuide was removed.

Figs 3d and 3e (left) Final prosthetic out-

come and (right) final radiograph of patient 3.

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Discussion

CT-guided implant surgery is becoming

a more common modality of implant

therapy. This article demonstrates the

versatility of CT-guided technology,

specifically of the Navigator SurgiGuide

system, which can facilitate the delivery

of internal-connection dental implants

and, when indicated, an immediate

dental prosthesis.

Several authors have demon-

strated that stereolithographically

generated CT surgical drilling guides

offer enhanced precision and accuracy

when compared to the conventional

nonguided approach to osteotomy site

preparation.10–15 Most of these arti-

cles have shown implant positioning

entry point (axial plane) deviations of

1 mm and angle deviations of around

5 degrees. The totally guided ap -

proach may further minimize these

entry point and angle deviations

because of the potential influence of

operator positioning error when using

more than one guide or placing

implants manually. Inherent errors

such as guide movement and the

influence of bone density need to be

considered on these deviations when

comparing both approaches.

Totally guided precision CT-

based surgery is not a panacea to

optimal implant positioning. Several

key elements influence the ability to

execute a desired treatment out-

come. These include, but are not lim-

ited to: (1) quality of the CT imaging,

including panoramic, cross-sectional,

and axial 2D views; (2) reliability of

the 3D reconstruction created by the

radiology technician using the com-

puter software; (3) quality of the

rapid-prototype medical modeling; (4)

the challenge of determining the accu-

rate position of thin crestal bone, which

often competes with other radiopaque

structures (eg, teeth, scanning appli-

ances); (5) regional anatomy charac-

teristics; (6) dimensional stability of the

stone cast that is optically imaged for

tooth-supported cases; (7) accurate

placement and stability of the scan-

ning appliance at the time of imaging;

(8) the extent of the radiation artifact;

(9) movement and fit of the guide dur-

ing surgical execution; and (10) the

knowledge and ex perience of the clin-

ician in CT analysis and interpretation.

The use of totally guided preci-

sion CT-based surgery offers the

opportunity for minimally invasive

implant surgery and the obvious clini-

cal benefits of reduced pain and

swelling associated with open flap

techniques.16 A totally guided

approach, however, is associated with

the highest risk and demands the most

attention to detail in all phases of treat-

ment. The use of rapid-prototype

medical modeling and computer-

guided implant dentistry creates the

unique ability to execute precise sur-

gical outcomes, facilitates the fabrica-

tion of a dental prosthesis prior to

surgery, and enables the delivery of

provisional teeth on the day of surgery.

These technologic advances

require cooperative and collaborative

input from all those responsible for

patient care. In reality, each clinician

must determine the most appropriate

diagnostic approach for a given situa-

tion. It is clear that this technology can

play a valuable role in improving patient

care and in reducing the likelihood of

undesirable outcomes.

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Acknowledgments

The authors would like to thank Materialise

Dental and Biomet 3i for supporting this case

series by supplying the guides, surgical instru-

mentation, and implant componentry.

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Mar 2020
J PROSTHET DENT

Statement of problem If the components in the acrylic resins used to fabricate interim crows are cytotoxic, they can interfere with the integrity of the adjacent periodontal tissue and the dentin-pulp complex. Purpose The purpose of this in vitro study was to assess the cytotoxicity of resin-based materials used to prepare interim crowns. Material and methods The following materials were used in this study: CAR, conventional acrylic resin powder and liquid; BR, bis-acrylic resin; and PAR, pressed acrylic resin of the CAD-CAM type. Glass disks were used as the control (Co). Oral epithelial cells (NOK) were seeded on glass disks and standardized disks prepared with the resins under study. After incubation for 24 hours, the cells were analyzed for viability (Alamar Blue and Live or Dead), adhesion, and morphology (SEM and fluorescence), as well as epidermal growth factor synthesis (EGF-ELISA). The surface roughness (Ra) of test specimens was evaluated under a confocal microscope. The data were submitted to ANOVA and the Tukey HSD statistical tests (α=.05). Results The highest Ra value was observed in BR in comparison with CAR, PAR, and Co (P<.05). The highest viability, adhesion, and EGF synthesis values were determined for the cells in contact with PAR (P<.001). Conclusions The computer-aided design and computer-aided manufacturing (CAD-CAM)-type resin favored adhesion, metabolism, and epithelial cell proliferation, and it was therefore considered cytocompatible.

Does flap opening or not influence the accuracy of semi-guided implant placement in partially edentulous sites?

Article

Sep 2019

Objective: To investigate the effect of open-flap or flapless approaches on the accuracy of implant placement partially guided by tooth-supported surgical templates. Materials and methods: A total of 36 edentulous sites were selected from seven human cadaver heads. Following the preoperative implant planning using Blue Sky Plan, surgical guides were fabricated by an in-office desktop 3D printer. All the sites were randomly divided into two groups: flapless approach (n = 18), and open-flap approach (n = 18). After guided osteotomy preparation with subsequent freehand implant placement, digital intraoral scanning was performed to obtain post-operative implant positions. Based on the image registration, the deviations between the planned and actual implant position were measured and compared. Results: Statistically significant variance differences between the two approaches were found in the global coronal (open-flap: 0.86 ± 0.23 mm; flapless: 1.3 ± 0.62 mm; P < .001), global apical (open-flap: 1.38 ± 0.37 mm; flapless: 1.9 ± 0.78 mm; P = .002), and depth (open-flap: 0.59 ± 0.34 mm; flapless 0.89 ± 0.78 mm; P < .001) deviations. The differences were not significant regarding lateral (coronal and apical) and angular deviations. Conclusions: In semi-guided implant surgery, the open-flap and flapless approaches demonstrate similar lateral and angular deviations. The open-flap group shows better depth control when manually inserting the implant.

Dynamic Navigation Systems for the Rehabilitation of the Atrophic Maxillae

Chapter

Mar 2023

The insertion of dental implants into the atrophic edentulous maxilla is a challenge due to the limited vertical height (resorption of the alveolar bone crest and pneumatization of the maxillary sinuses following the extraction of the upper molars) as well as low bone density in that area. The use of computer-aided implantology (CAI) helps the clinician transfer the implant prosthetic digital plan to the jaw using the entire available native bone. Two computer-aided approaches are possible: one, with more than 20 years of history, is static CAI, which is represented by a system connecting a virtual project with its own physical object represented by surgical guides used to perform both osteotomies and implant seating, and the other is called dynamic computer-aided implantology (DCAI). Dynamic CAI is also divided into two possible different approaches that are currently used: one is referred to as robotics and the other is referred to as augmented reality, in which the operator collocated at the center of the surgery belongs to the augmented reality. It works like a Global Positioning System (GPS) by making a triangulation with two cameras, a contra angle handpiece, and the patient’s jaw. In this manner, on the screen, the clinician can follow the real-time drilling and implant placement process with a minimally invasive approach using the entire native bone.

A short review on guided implant surgery and its efficiency

Article

Sep 2022
Bioinformation

Arvina Rajasekar

Ideal implant placement may reduce surgical complications, such as nerve injury and lingual cortical plate perforation, and minimize the likelihood of functional and prosthetic compromises. Guided implant surgery [GIS] has been used as the means to achieve ideal implant placement. GIS refers to the process of digital planning, custom-guide fabrication, and implant placement using the custom guide and an implant system–specific guided surgery kit. GIS includes numerous additional steps beyond the initial prosthetic diagnosis, treatment planning, and fabrication of surgical guides. Substantial errors can occur at each of these individual steps and can accumulate, significantly impacting the final accuracy of the process with potentially disastrous deviations from proper implant placement. Pertinent overall strategies to reduce or eliminate these risks can be summarized as follows: complete understanding of the possible risks is fundamental; knowledge of the systems and tools used is essential; consistent verification of both diagnostic and surgical procedures after each step is crucial; proper training and surgical experience are critical. This review article summarizes information on the accuracy and efficacy of GIS, provides insight on the potential risks and problems associated with each procedural step, and offers clinically relevant recommendations to minimize or eliminate these risks.

The expanding influence of computed tomography and the application of computer guided implantology

Article

Full-text available

Jun 2008

Implant dentistry is changing. There are currently two types of computed tomogrophy (CT) scanners--multi-slice and cone beam--available to the dental professional. Computed tomography allows for proactive planning among the entire implant team and with the patient, a concept referred to as "collaborative accountability" In addition, CT surgical guidance that enhances accuracy and precision is available to ensure prosthetic outcomes. A logical and progressive approach is outlined that allows each clinician to assess how to embrace this paradigm shift in his or her clinical practice, and provide better and safer patient care.

Accuracy of implant placement with stereolithographic surgical guide

Article

Full-text available

Nov 2002

Placement of dental implants requires precise planning that accounts for anatomic limitations and restorative goals. Diagnosis can be made with the assistance of computerized tomographic (CT) scanning, but transfer of planning to the surgical field is limited. Recently, novel CAD/CAM techniques such as stereolithographic rapid prototyping have been developed to build surgical guides in an attempt to improve precision of implant placement. However, comparison of these advanced techniques to traditional surgical guides has not been performed. The goal of this study was to compare the accuracy of a conventional surgical guide to that of a stereolithographic surgical guide. CT scanning of epoxy edentulous mandibles was performed using a cone beam CT scanner with high isotropic spatial resolution, while planning for 5 implants on each side of the jaw was performed using a commercially available software package. Five surgeons performed osteotomies on a jaw identical to the initial model; on the right side a conventional surgical guide (control side) was used, and on the left side a stereolithographic guide was used (test side). Each jaw was then CT scanned, and a registration method was applied to match it to the initial planning. Measurements included distances between planned implants and actual osteotomies. The average distance between the planned implant and the actual osteotomy was 1.5 mm at the entrance and 2.1 mm at the apex when the control guide was used. The same measurements were significantly reduced to 0.9 mm and 1.0 mm when the test guide was used. Variations were also reduced with the test guide, within surgeons and between surgeons. Surgical guidance for implant placement relieves the clinician from multiple perioperative decisions. Precise implant placement is under investigation using sophisticated guidance methods, including CAD/CAM templates. Within the limits of this study, implant placement was improved by using a stereolithographic surgical guide.

Use of stereolithographic models as diagnostic and restorative aids for predictable immediate loading of implants

Article

Full-text available

Nov 2003

Scott D. Ganz

Implant dentistry has evolved into one of the most predictable treatment alternatives in all of medical science. Advances in the surgical and prosthetic components, implant designs and surface technologies, and imaging techniques have allowed for significant modifications to occur with respect to one- and two-stage surgical protocols, accelerating treatment times to the benefit of patient and clinician. This article presents a technique to improve surgical and restorative accuracy, allowing for predictable placement and immediate loading of implants through use of CT imaging, stereolithographic models, and CT-derived surgical templates.

Clinical Application of Stereolithographic Surgical Guides for Implant Placement: Preliminary Results

Article

Full-text available

May 2005

The success of implant-supported restorations requires detailed treatment planning, which includes the construction of a surgical guide. Recently, computer-aided rapid prototyping has been developed to construct surgical guides in an attempt to improve the precision of implant placement. The aim of the present study was to evaluate the match between the positions and axes of the planned and placed implants when a stereolithographic surgical guide is employed. Six surgical guides used in four patients (three women, one man; age from 23 to 65 years old) were included in the study and 21 implants were placed. A radiographic template was fabricated and computer-assisted tomography (CT) was performed. The virtual implants were placed in the resulting 3-dimensional image. Using a stereolithographic machine, liquid polymer was injected and laser-cured according to the CT image data with the planned implants, generating three surgical guides, with increasing tube diameters corresponding to each twist drill diameter (2.2, 3.2, and 4.0 mm), for each surgical area. During the implant operation, the surgical guide was placed on the jawbone and/or the teeth. After surgery, a new CT scan was taken. Software was used to fuse the images of planned and placed implants, and the locations and axes were compared. On average, the match between the planned and the placed implant axes was within 7.25 degrees +/- 2.67 degrees ; the differences in distance between the planned and placed positions at the implant shoulder were 1.45 +/- 1.42 mm, and 2.99 +/- 1.77 mm at the implant apex. In all patients, a greater distance was found between the planned and placed positions at the implant apex than at the implant head. Clinical data suggest that computer-aided rapid prototyping of surgical guides may be useful in implant placement. However, the technique requires improvement to provide better stability of the guide during the surgery, in cases of unilateral bone-supported and non-tooth-supported guides. Further clinical studies, using greater number of patients, are necessary to evaluate the real impact of the stereolithographic surgical guide on implant therapy.

Implantologie assistèe par ordinateur: le propramme SimPlant/SurgiCase et le SAFE System mis en charge immediate d'unbridge mandibulaire avec des impalt transmuqueux

Article

Jan 2003

Accuracy of drilling guides for the transfer from 3-D CT based planning to placement of zygomatic implants in human cadavers

Article

Feb 2003

The accuracy of surgical drilling guides was assessed for placement of zygoma implants. Six zygoma fixtures of length 45 mm (Nobel Biocare, Göteborg, Sweden) were placed in three formalin-fixed human cadavers using surgical drilling guides. The fabrication of these custom-made drilling guides was based on three-dimensional computerized tomography (3D-CT) data for the maxillary-zygomatic complex. The installation of the implants was simulated preoperatively using an adopted 3D-CT planning system. In addition, anatomical measurements of the zygomatic bone were performed on the 3D images. The preoperative CT images were then matched with postoperative ones in order to assess the deviation between the planned and installed implants. The angle between the planned and actually placed implants was < 3 degrees in four out of six cases. The largest deviation found at the exit point of one of the six implants was 2.7 mm. The present study showed that the use of surgical drilling guides should be encouraged for zygoma implant placement because of the lengths of the implants involved and the anatomical intricacies of the region.

Stereolithographic surgical templates for placement of dental implants in complex cases

Article

Jul 2003

In recent years, dental implant rehabilitation has faced demands from prosthetic and esthetic arenas that call for increasingly ideal outcomes, which require precise surgical planning and placement. Anatomic limitations and bone quantity and quality can now be evaluated using more sophisticated radiographic techniques, although transferring this information to the surgical phase has been at best a difficult task. Recently, computer-aided design and manufacturing have made it possible to use data from computerized tomography to not only plan implant rehabilitation, but also to transfer this information to the surgery. One of these techniques uses stereolithography, a laser-driven polymerization process that fabricates an anatomic model and surgical templates. This novel approach is illustrated with two advanced cases, demonstrating that the technique not only allows for the precise translation of the treatment plan directly to the surgical field, but also offers many significant benefits over traditional procedures.

Computer-assisted implant placement. A case report: Treatment of the mandible

Article

Nov 2002

The authors present a case of immediate loading of mandibular implants using a 5-step procedure. The first step consists of building a scannographic template, the second step consists of taking a computerized tomographic (CT) scan, and the third step consists of implant planning using SurgiCase software. The final 2 steps consist of implant placement using a drill guide created by stereolithography and placement of the prosthesis. Using a CT scan-based planning system, the surgeon is able to select the optimal locations for implant placement. By incorporating the prosthetic planning using a scannographic template, the treatment is optimized from a prosthetic point of view. Furthermore, the use of a stereolithographic drill guide allows a physical transfer of the implant planning to the patient's mouth. The scannographic template is designed so that it can be transformed into a temporary fixed prosthesis for immediate loading, and the definitive restoration is placed 3 months later.

Prosthetically directed implant placement using computer software to ensure precise placement and predictable prosthetic outcomes. Part 1: Diagnostics, imaging, and collaborative accountability

Article

Jul 2006

The need for an accurate diagnosis and treatment plan remains essential for predictable treatment outcomes with dental implants. Advances in computerized tomography (CT) technology now enable the execution of a surgical outcome based on presurgical planning. Precise implant placement no longer relies on socalled mental navigation but rather can be computer guided, based on a three-dimensional, prosthetically directed plan. Current CT technology enables all implant team members to embrace the concept of collaborative accountability, which can ensure consistent outcomes. Clinicians can fabricate an implant-supported prosthesis presurgically using patients' CT scan data. The purpose of this paper is to discuss the use of scanning appliances to transfer clinically relevant prosthetic outcome information to a CT data set. With SimPlant software, this information can be used to provide a pretreatment outcome analysis, which can be used for fabrication of stereolithographic models and surgical drilling guides used during osteotomy preparation.

Prosthetically directed implant placement using computer software to ensure precise placement and predictable prosthetic outcomes. Part 2: Rapid-prototype medical modeling and stereolithographic drilling guides requiring bone exposure

Article

Sep 2006

The purpose of this paper is to expand on part 1 of this series (published in the previous issue) regarding the emerging future of computer-guided implant dentistry. This article will introduce the concept of rapid-prototype medical modeling as well as describe the utilization and fabrication of computer-generated surgical drilling guides used during implant surgery. The placement of dental implants has traditionally been an intuitive process, whereby the surgeon relies on mental navigation to achieve optimal implant positioning. Through rapid-prototype medical modeling and the ste-reolithographic process, surgical drilling guides (eg, SurgiGuide) can be created. These guides are generated from a surgical implant plan created with a computer software system that incorporates all relevant prosthetic information from which the surgical plan is developed. The utilization of computer-generated planning and stereolithographically generated surgical drilling guides embraces the concept of collaborative accountability and supersedes traditional mental navigation on all levels of implant therapy.

Computer-Guided Implant Dentistry for Precise Implant Placement: Combining Specialized Stereolithographically Generated Drilling Guides and Surgical Implant Instrumentation

Abstract and Figures

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