92 2a jung - iti.org · relevant information about (1) the accuracy and (2) the clinical...

92 Volume 24, Supplement, 2009

Osseointegration of dental implants is today con-sidered to be highly predictable.1,2 Even in

patients with bone atrophy and in locations previ-ously considered unsuitable for implants, implantplacement has been made possible through boneregeneration techniques.3,4 The predictability ofthese techniques has allowed placement of implantsaccording to the prosthetic requirements.

Conventional dental panoramic tomography andperiapical radiography are often performed with thepatient wearing a radiographic template simulatingthe preoperative prosthetic design. However, theseimaging techniques do not provide complete three-dimensional (3D) information of the patient’s anatomy.In addition, conventional surgical templates have beenfabricated on the diagnostic cast that will direct thebone entry point and angulations of the drill, but theyneither reference the underlying anatomical structuresnor provide exact 3D guidance.5,6

To overcome these limitations in dental implantol-ogy, current research has been dedicated to develop-ing techniques that can provide optimal 3D implantpositioning with respect to both prosthetic andanatomical parameters. The introduction of computedtomography (CT), 3D implant planning software, and

Computer Technology Applications in Surgical Implant Dentistry: A Systematic Review

Ronald E. Jung, PD, Dr Med Dent1/David Schneider, Dr Med, Dr Med Dent1/Jeffrey Ganeles, DMD2/Daniel Wismeijer, DMD, PhD3/Marcel Zwahlen, PhD4/

Christoph H. F. Hämmerle, DMD, Dr Med Dent5/Ali Tahmaseb, DDS6

Purpose: To assess the literature on accuracy and clinical performance of computer technology applications insurgical implant dentistry. Materials and Methods: Electronic and manual literature searches were conductedto collect information about (1) the accuracy and (2) clinical performance of computer-assisted implant systems.Meta-regression analysis was performed for summarizing the accuracy studies. Failure/complication rates wereanalyzed using random-effects Poisson regression models to obtain summary estimates of 12-month propor-tions. Results: Twenty-nine different image guidance systems were included. From 2,827 articles, 13 clinicaland 19 accuracy studies were included in this systematic review. The meta-analysis of the accuracy (19 clinicaland preclinical studies) revealed a total mean error of 0.74 mm (maximum of 4.5 mm) at the entry point in thebone and 0.85 mm at the apex (maximum of 7.1 mm). For the 5 included clinical studies (total of 506 implants)using computer-assisted implant dentistry, the mean failure rate was 3.36% (0% to 8.45%) after an observationperiod of at least 12 months. In 4.6% of the treated cases, intraoperative complications were reported; theseincluded limited interocclusal distances to perform guided implant placement, limited primary implant stability,or need for additional grafting procedures. Conclusion: Differing levels and quantity of evidence were availablefor computer-assisted implant placement, revealing high implant survival rates after only 12 months of observa-tion in different indications and a reasonable level of accuracy. However, future long-term clinical data are nec-essary to identify clinical indications and to justify additional radiation doses, effort, and costs associated withcomputer-assisted implant surgery. INT J ORAL MAXILLOFAC IMPLANTS 2009;24(SUPPL):92–109

Key words: computer-assisted implant dentistry, dental implants, navigation

1Senior Lecturer, Department of Fixed and Removable Prostho-dontics and Dental Material Science, Center for Dental and OralMedicine and Cranio-Maxillofacial Surgery, University of Zurich,Zurich, Switzerland.

2Clinical Associate Professor, Department of Periodontology,Nova Southeastern University College of Dental Medicine,Fort Lauderdale, Florida, USA.

3Professor and Head, Department of Oral Implantology and Prosthetic Dentistry, Academic Centre for Dentistry Amsterdam(ACTA) University of Amsterdam and VU University, Amsterdam,The Netherlands.

4Assistant Professor, Institute of Social and Preventive Medicine,University of Bern, Bern, Switzerland.

5Professor and Head, Department of Fixed and RemovableProsthodontics and Dental Material Science, Center for Dentaland Oral Medicine and Cranio-Maxillofacial Surgery, University ofZurich, Zurich, Switzerland.

6Senior Lecturer, Department of Prosthodontics and Implant Dentistry, Free University of Amsterdam School of Dentistry,Amsterdam, The Netherlands.

None of the authors reported a conflict of interest.

Correspondence to: PD Dr Ronald E. Jung, Clinic for Fixed andRemovable Prosthodontics, Center for Dental and Oral Medicineand Cranio-Maxillofacial Surgery, University of Zurich, Platten-strasse 11, CH-8032 Zurich, Switzerland. Fax: +41 44 634 4305.Email: [email protected]

This review paper is part of the Proceedings of the Fourth ITI Con-sensus Conference, sponsored by the International Team for Implan-tology (ITI) and held August 26–28, 2008, in Stuttgart, Germany.

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The International Journal of Oral & Maxillofacial Implants 93

Group 2

CAD/CAM (computer-aided design/computer-assistedmanufacturing) technology have undoubtedly beenimportant achievements in this field. The digital CT(also including cone beam CT, or CBCT) images derivedin this way can be converted into a virtual 3D model ofthe treatment area. This provides the practitioner witha realistic view of the patient’s bony anatomy, thus per-mitting a virtual execution of the surgery in an idealand precise prosthetically driven manner.

Different approaches have been introduced totransfer this planned digital information to the clinicalsituation. Mechanical positioning devices or drillingmachines convert the radiographic template to a surgi-cal template by executing a computer transformationalgorithm.5,6 Other approaches include CAD-CAM tech-nology to generate stereolithographic templates or burtracking to allow for intraoperative real-time trackingof the drills according to the planned trajectory.The so-called navigation systems visualize the actual positionof the surgical instrument in the surgical area on thereconstructed 3D image data of the patient on a screen“chairside”(see Appendix for definitions).

The use of these computer-assisted technologiesis often restricted to the surgical aspects of implanttreatment. Prosthetic treatment still has to be carriedout following conventional protocols. However, thelink to transfer prosthetic information to the patientis of great importance, and exact reference points arerequired to position the implants in such a way thatprefabricated prosthetics have a precise fit.7

Today, a growing body of literature on the topic ofcomputer-assisted implant dentistry is available.Authors report about different guided techniques,about the accuracy of the position of the implantscompared to the virtual digital planning, and aboutclinical and patient-centered outcomes. As many ofthese techniques are already available in clinical prac-tice or are on the way to becoming established as rou-tine clinical treatment options, it is of greatimportance to analyze the currently available systems.This will allow discussion of the possibilities and limi-tations of computer-assisted implant dentistry in clini-cal applications. Hence, the aim of this systematicreview was to systematically assess the literatureregarding the accuracy and the clinical performanceof computer technology applications in surgicalimplant dentistry.

MATERIALS AND METHODS

An electronic literature search of the PubMed data-base was performed with the intention of collectingrelevant information about (1) the accuracy and (2)the clinical performance of computer-assisted

implant systems. The search included articles pub-lished from 1966 up to December 2007 in the dentalliterature.The search was limited to studies in English,German, Italian, or French, using the terms dental,implant, implants, implantation, implantology, com-pute*, guid*, and navigat*, and was performed bytwo independent reviewers. Every search was com-plemented by manual searches of the reference listsof all selected full-text articles. Additionally, full-textcopies of review articles published between January2004 and December 2007 were obtained.

Inclusion CriteriaThe applied inclusion criteria were different for thestudies focusing on accuracy and for the studiesfocusing on clinical outcomes. For the accuracy stud-ies, clinical, preclinical, and ex vivo studies wereincluded. The primary outcome of the experimentshad to be accuracy of computer-assisted implantdentistry. Only studies providing exact informationabout the amount and direction of implant or instru-ment deviation were included.

For the clinical studies at least five patients had tobe included. A follow-up period was not defined forevaluation of intraoperative complications or unex-pected events during operation. However, for the eval-uation of implant and prosthetic survival andcomplication rates, the minimum follow-up time wasset at 12 months. The reported treatment outcomeshad to include at least one of the following parameters:clinical, radiographic, or patient-centered outcomes ofcomputer-assisted implant dentistry in humans.

Exclusion CriteriaStudies not meeting all inclusion criteria wereexcluded from the review. Case reports with fewerthan five patients were not included for the analysisof accuracy or for clinical studies. Studies with zy-goma implants, pterygoid implants, or mini-implantsfor orthodontic purposes were excluded. Publicationswere also excluded if the study exclusively reportedon the radiographic planning.

Data ExtractionTwo reviewers independently extracted the data usingdata extraction tables. Any disagreements were re-solved by discussion. Data were only included in theanalysis if there was agreement between the tworeviewers.

Statistical AnalysisThe statistical analysis comprised two parts: (1) asummary of the evidence from the accuracy studiesand (2) a summary of the outcomes reported fromthe clinical studies. For summarizing the accuracy

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Jung et al

studies, methods appropriate for meta-analysis of themean values observed in groups of a given size wereused. The ideal information for this would be to havethe mean and its standard error and then to performinverse variance weighted fixed or random effectsmeta-analysis. The standard error (SE) can be derivedfrom the observed standard deviation (SD) of theaccuracy values using the formula: SE = SD/÷n, wheren is the number of observations in the study. There-fore, when the mean or the standard deviation wasnot reported in the original article, it was imputedusing the available information according to the for-mulae given in Table 3 of the research methods arti-cle by Hozo and colleagues.8 Heterogeneity betweenstudies was assessed with the I2 statistic as a measure

of the proportion of total variation in estimates that isdue to heterogeneity,9 where I2 values of 25%, 50%,and 75% are considered as cutoff points for low, mod-erate, and high degrees of heterogeneity. Meta-regression analyses were done to perform formalstatistical tests of the differences in mean accuracyaccording to the groupings of the studies.10

For summarizing the outcomes reported from theclinical studies, methods described in detail in a sys-tematic review of fixed partial dentures were used.1

Briefly, for each report the event rate was calculated bydividing the number of events (failures or intraopera-tive complications) in the numerator by the total expo-sure time in the denominator. Total exposure time wasapproximated by multiplying the number of implantsby the mean follow-up time reported in the studies. Forfurther analysis, the total number of events was consid-ered to conform to a Poisson distribution for a givensum of exposure time, and Poisson regression with alogarithmic link function and total exposure time perstudy as an offset variable were used. To assess hetero-geneity of the study-specific event rates, the Spearmangoodness-of-fit statistics and associated P value werecalculated. If the goodness-of-fit P value was below .05,indicating heterogeneity, random-effects Poissonregression (with g-distributed random effects) wasused to obtain a summary estimate of the event rates.

Summary estimates and 95% confidence intervals(95% CI) and P values from meta-regression or Pois-son regression for assessing differences in outcomesbetween groups of studies are reported. All analyseswere done using Stata (StataCorp) version 10.

RESULTS

After initial identification of a total of 2,827 titles, theexclusion of irrelevant studies was performed by twoindependent reviewers, who reduced the number oftitles to 182. After review of these manuscripts’ ab-stracts, 85 publications were selected for full-textevaluation. Thirteen clinical and 19 accuracy studieswere ultimately used for this review (Fig 1).Fig 1 Literature search and selection of articles.

First electronic and hand search: 2,827 titles

Independently selected by two reviewers: 182 titles

Discussion, agreement on

79 abstracts full text obtained

79 full-text articles

19 articles on “accuracy”

13 articles on “clinical performance”

Excluded articles:• 19 description of

method• 16 case reports• 5 insufficient informa-

tion on accuracy• 2 insufficient follow-up

data• 2 reports on Zygoma

implants

Table 1 Distribution and Number of Specimens (Humans, Cadavers, or Models) According to Location andDentition

Maxilla Mandible

Part Dentition PartEdentulous

Part Specimens Total Edent edent unknown Total Edent edent Unknown Total Unknown edent Unknown

Model 112 46 20 26 56 29 11 16 30 1 31 10Cadaver 6 1 1 3 3 2Human 33 29 21 8 41 20 4Total 151 47 20 27 88 50 11 27 71 21 31 16

Edent = edentulous; Part edent = partially edentulous.

Full number of studies

included: 32

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Jung et al

Accuracy StudiesLiterature. Nineteen articles from the systematicreview, published from 2001 to 2007, provided usefulinformation about accuracy in computer-assistedimplant dentistry. Twelve research groups from sevencountries were involved.

Material. Eleven in vitro studies were performedon models, mostly made of acrylate. Of the remainingeight studies, four reported the use of human cadav-ers and four were available as clinical studies with atotal of 45 patients. In 16 of these patients, implantswere placed in an edentulous mandible, in 20 cases inedentulous jaws without further specification, and inthe remaining cases the location was not reported(Tables 1 and 2).

Systems. Nine different computer-assisted implan-tation systems were tested (Table 3). The majority ofthe systems were “dynamic” systems, based on intra-operative feedback produced by recording the posi-tion of the handpiece with infrared cameras (sixsystems) or by haptic feedback (one system,PHANToM11). These navigational systems were used in19 studies at 1,041 implant sites (Tables 2 and 4). Twoof the nine systems used drill guides, based on thecomputer-assisted implant planning; 261 implant siteswere drilled or implanted with the assistance of a drillguide.

Drillings/Implants/Positions and Their Evalua-tion. A total of 1,302 positions were evaluated (Tables2 and 4); 360 of the positions were measured onimplants, with 100 of these placed in models, 63 inhuman cadavers, and 197 in humans. The remaining942 positions were assessed on drill holes made inmodels. In the majority of the studies (14 studies) a CTscan was performed to assess the accuracy, whereasonly in three studies was the position of the drill holesor implants directly measured in models.12–14 Calcula-tion of the error by registration of the handpiece or3D probe position after drilling and by coordinatemeasurements was used in two studies.15,16

To assess the accuracy of the implant systems, thefollowing parameters were selected:

a. Deviation error in a horizontal direction at theentry point of the drill or implant

b. Beviation error in a horizontal direction at theapex of the drill or implant

c. Deviation in height (vertical direction) d. Deviation of the axis of the drill or implant

For the first two parameters, the extracted dataallowed a statistical analysis (Table 2). Regarding thelatter two parameters, data were insufficient for ameta-analysis.

(a and b) Error at Entry Point and Apex (Figs 2 to 9).The overall mean error at the entry point was 0.74(95% CI: 0.58 to 0.90) mm with a maximum of 4.5 mm,while the mean error at the apex was 0.85 (95% CI:0.72 to 0.99) mm with a maximum of 7.1 mm.

With systems using surgical guides, the mean errorwas 1.12 (95% CI: 0.82 to 1.42) mm (max 4.5 mm) at theentry point and 1.2 (95% CI: 0.87 to 1.52) mm (max 7.1mm) at the apex. For dynamic intraoperative naviga-tion (14 studies) the mean error was 0.62 (95% CI: 0.43to 0.81) mm (max 3.4 mm) at the entry point and 0.68(95% CI: 0.55 to 0.80) mm (max 3.5 mm) at the apex.The dynamic systems showed a statistically signifi-cantly higher mean precision by 0.5 mm (P = .0058) atthe entry point and by 0.52 mm (P = .0354) at the apex.

Implants positioned in humans showed a highermean deviation at entry point and apex compared toimplants or drills in cadaver studies (� entry = 0.32mm, P = .0497; � apex = 0.02 mm, P = .8546) andstudies on models (� entry = 0.43 mm, P = .0015; �apex = 0.33 mm, P = .1245).

The mean error was significantly higher in studiesin which the position of implants was measured,compared to studies in which the position of drillholes was assessed (� entry = 0.3 mm, P = .0103; �apex = 0.33 mm, P = .0578).

Table 4 Distribution and Number of EvaluatedSites in Terms of Accuracy

No. of sites No. of studies

Navigation 1,041 14Guide 261 5Model 1,042 10Cadaver 63 4Human 197 5Drill 942 10Implant 360 9

Table 3 Systems Used in Studies Reporting onAccuracy

System No. of studies

DynamicIGI, DenX 5VISIT 4Treon 4SMN, Zeiss 2Vector Vision 1Robodent 1PHANToM 1

StaticSimPlant 2Nobel Biocare 2

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Group 2

Principle of system

StaticNobelNobelSimPlantSimPlantSimPlantSubtotal (I-squared = 89.2%, P = .000)

DynamicIGI, DenXIGI, DenXIGI, DenXRobodentPHANToMRobodentTreonTreonTreonVISITVISITVISITVISITVector VisionSubtotal (I-squared = 96.3%, P = .000)

Overall (I-squared = 97.9%, P = .000)

0 1 2

Mean entryError, mm (95% CI)

1.10 (0.70, 1.50)0.80 (0.65, 0.951.50 (1.31, 1.69)0.90 (0.76, 1.04)1.45 (0.84, 2.06)1.12 (0.82, 1.42)

0.25 (0.14, 0.36)0.40 (0.32, 0.48)0.43 (0.31, 0.55)0.65 (0.36, 0.94)0.16 (0.08, 0.24)0.35 (0.26, 0.44)1.10 (0.87, 1.33)0.42 (0.37, 0.47)1.20 (1.02, 1.38)0.52 (0.37, 0.67)0.90 (0.76, 1.04)0.57 (0.35, 0.80)0.85 (0.71, 0.99)0.95 (0.92, 0.98)0.62 (0.43, 0.81)

0.74 (0.58, 0.90)

Fig 2 Mean deviation at entrypoint, stratified by principle of sys-tem (static vs dynamic).

Principle of system

StaticNobelNobelSimPlantSimPlantSimPlantTreonTreonSubtotal (I-squared = 96.9%, P = .000)

DynamicIGI, DenXIGI, DenXIGI, DenXRobodentTreonTreonTreonVISITVISITVISITVISITSubtotal (I-squared = 89.6%, P = .000)


0 1 2

Mean apexError, mm (95% CI)

1.20 (0.80, 1.60)0.90 (0.75, 1.05)2.99 (2.23, 3.75)2.10 (1.83, 2.37)1.00 (0.83, 1.17)0.60 (0.52, 0.68)0.50 (0.42, 0.58)1.20 (0.87, 1.52)

0.68 (0.52, 0.84)0.40 (0.24, 0.56)0.45 (0.36, 0.54)0.47 (0.38, 0.56)0.75 (0.56, 0.94)0.80 (0.67, 0.93)0.40 (0.32, 0.48)0.78 (0.44, 1.12)1.20 (0.89, 1.51)1.40 (1.07, 1.73)0.65 (0.56, 0.74)0.68 (0.55, 0.80)

0.85 (0.72, 0.99)

Fig 3 Mean deviation at apex,stratified by principle of system(static vs dynamic).

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(c) Error in Height ( Table 2). The mean error inheight was reported in seven studies, all of whichwere performed on models using a dynamic implantsystem. Only one of these seven studies usedimplants14; all others used drill holes for the evalua-tion of the system accuracy. The median error inheight was 0.23 mm, with a maximum of 1.43 mm.

(d) Error in Angulation (Table 2). Information aboutthe deviation in angulations was found in nine stud-ies. The median error in angulation was 4.0 degrees,with a maximum of 20.43 degrees.

Clinical StudiesLiterature. Thirteen human studies identified by sys-tematic review and published from 2001 to 2007 pro-vided information about clinical, radiographic, orpatient-centered outcomes in computer-assisted

implant dentistry. Only two studies were randomizedcontrolled clinical studies,17,18 whereas the remaining11 studies were prospective studies.

Material. A total of 580 patients with 1,243 im-plants were treated with computer-assisted implantdentistry and have been included in this review. Themean age was 56.1 years, with a range from 18 to 89years. The mean follow-up period was 7.7 (0 to 26.4)months. The majority of the studies reported onedentulous patients in the maxilla and mandible.However, there were also studies treating single-tooth gaps and partially edentulous patients.

In 6 of the 13 included studies an immediaterestoration of the implants was performed. In addi-tion, all of these implants were inserted using a flap-less procedure (Table 5).

System

NobelcadavercadaverSubtotal (I-squared = 48.4%, P = .164)

SimPlantmodelmodelhumanSubtotal (I-squared = 92.2%, P = .000)

TreonhumanmodelhumanSubtotal (I-squared =98.0%, P = .000)

IGI, DenXmodelmodelmodelmodelSubtotal (I-squared = 67.4%, P = .027)

PHANToMmodelSubtotal (I-squared = %, P = )

RobodentmodelSubtotal (I-squared = %, P = )

VISITcadaverhumancadaverhumanSubtotal (I-squared = 83.1%, P = .001)

Vector VisionmodelSubtotal (I-squared = %, P = )


0 1 2


1.10 (0.70, 1.50)0.80 (0.65, 0.95)0.89 (0.62, 1.16)

1.50 (1.31, 1.69)0.90 (0.76, 1.04)1.45 (0.84, 2.06)1.26 (0.77, 1.74)

1.10 (0.87, 1.33)0.42 (0.37, 0.47)1.20 (1.02, 1.38)0.90 (0.31, 1.49)

0.25 (0.14, 0.360.40 (0.32, 0.48)0.43 (0.31, 0.55)0.65 (0.36, 0.94)0.39 (0.28, 0.50)

0.16 (0.08, 0.24)0.16 (0.08, 0.24)

0.35 (0.26, 0.44)0.35 (0.26, 0.44)

0.52 (0.37, 0.67)0.90 (0.76, 1.04)0.57 (0.35, 0.80)0.85 (0.71, 0.99)0.72 (0.53, 0.91)

0.95 (0.92, 0.98)0.95 (0.92, 0.98)

0.74 (0.58, 0.90)

Fig 4 Mean deviation at entrypoint, stratified by system.

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Systems. The included studies reported about 10different dynamic and static systems (Table 6). In allexcept one study,19 in which a cone beam techniquewas used for preoperative planning, a CT scan wasperformed for that purpose.

Treatment Outcomes. The majority of the studiesdescribed intraoperative complications and reliabilityof the implant placement after computer-assistedimplant planning. Other studies have looked at theassessment of pain, the operating room time, andmarginal bone remodeling. Due to the short meanobservation time, it was difficult to assess implantsurvival or success rates. However, 5 of the 13 studiesreported an observation period of at least 12 months(Table 7).These studies have been included in the sta-tistical analysis.

The mean annual implant failure rate for all 5 stud-ies was 3.36%, ranging from 0% to 8.45%. In immedi-ately restored cases the failure rate was significantly

lower (P = .0018) by a factor of 5. A delayed restora-tion protocol was used in only one study with 29patients and 71 implants.20

Ten of 13 studies reported on intraoperative com-plications, including interocclusal distances that weretoo limited to perform guided implant placement,limited primary stability of the inserted implants, orthe need for additional grafting procedures (seeTable 5). Intraoperative complications or unexpectedevents were observed in 4.6% (95% CI: 1.2% to 16.5%)of the implant placements. Dynamic systems showeda 2.2 times higher incidence of complications,although this ratio was not significant (P = .5282). Inflapless procedures, the rate ratio for complicationswas 0.15 (95% CI: 0.03 to 0.88, P = .035), 7 times lowercompared to procedures with an open flap. In eden-tulous patients, the rate ratio for complications was0.23 (95% CI: 0.02 to 2.6, P = .237), 4 to 5 times lowerthan in partially edentulous patients.

System

NobelcadavercadaverSubtotal (I-squared = 48.4%, P = .164)

SimPlantmodelmodelhumanSubtotal (I-squared = 96.9%, P = .000)

TreonmodelmodelhumanhumanmodelSubtotal (I-squared = 88.6%, P = .000)

IGI, DenXmodelmodelmodelSubtotal (I-squared = 73.9%, P = .022)

RobodentmodelSubtotal (I-squared = %, P = )

VISITcadaverhumancadaverhumanSubtotal (I-squared = 89.4%, P = .000)


0 1 2


1.20 (0.80, 1.60)0.90 (0.75, 1.05)0.99 (0.72, 1.26)

2.99 (2.23, 3.75)2.10 (1.83, 2.37)1.00 (0.83, 1.17)1.97 (0.98, 2.97)

0.60 (0.52, 0.68)0.50 (0.42, 0.58)0.75 (0.56, 0.94)0.80 (0.67, 0.93)0.40 (0.32, 0.48)0.60 (0.47, 0.73)

0.68 (0.52, 0.84)0.40 (0.24, 0.56)0.45 (0.36, 0.54)0.50 (0.36, 0.65)

0.47 (0.38, 0.56)0.47 (0.38, 0.56)

0.78 (0.44, 1.12)1.20 (0.89, 1.51)1.40 (1.07, 1.73)0.65 (0.56, 0.74)0.99 (0.61, 1.37)

0.85 (0.72, 0.99)

Fig 5 Mean deviation at apex,stratified by system.

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Study design

CadaverNobelNobelVISITVISITSubtotal (I-squared = 75.0%, P = .007)

HumanSimPlantTreonTreonVISITVISITSubtotal (I-squared = 71.6%, P = .007)

ModelIGI, DenXIGI, DenXIGI, DenXIGI, DenXPHANToMRobodentSimPlantSimPlantTreonVector VisionSubtotal (I-squared =98.9%, P = .000)


0 1 2


0.80 (0.65, 0.95)1.10 (0.70, 1.50)0.57 (0.35, 0.80)0.52 (0.37, 0.67)0.71 (0.50, 0.91)

1.45 (0.84, 2.06)1.20 (1.02, 1.38)1.10 (0.87, 1.33)0.85 (0.71, 0.99)0.90 (0.76, 1.04)1.03 (0.86, 1.19)

0.43 (0.31, 0.55)0.25 (0.14, 0.36)0.65 (0.36, 0.94)0.40 (0.32, 0.48)0.16 (0.08, 0.24)0.35 (0.26, 0.44)0.90 (0.76, 1.04)1.50 (1.31, 1.69)0.42 (0.37, 0.47)0.95 (0.92, 0.98)0.60 (0.36, 0.83)

0.74 (0.58, 0.90)

Fig 6 Mean deviation at entrypoint, stratified by study design(cadaver, human, model).

Study design

CadaverNobelNobelVISITVISITSubtotal (I-squared = 70.0%, P = .018)

HumanSimPlantTreonTreonVISITVISITSubtotal (I-squared = 91.5%, P = .000)

ModelIGI, DenXIGI, DenXIGI, DenXIGI, DenXPHANToMRobodentSimPlantSimPlantTreonSubtotal (I-squared =95.7%, P = .000)


0 1 2


1.20 (0.80, 1.60)0.90 (0.75, 1.05)0.78 (0.44, 1.12)1.40 (1.07, 1.73)1.05 (0.79, 1.31)

2.99 (2.23, 3.75)0.75 (0.56, 0.94)0.80 (0.67, 0.93)1.20 (0.89, 1.51)0.65 (0.56, 0.74)1.03 (0.74, 1.31)

0.68 (0.52, 0.84)0.40 (0.24, 0.56)0.45 (0.36, 0.54)0.47 (0.38, 0.56)2.10 (1.83, 2.37)1.00 (0.83, 1.17)0.40 (0.32, 0.48)0.50 (0.42, 0.58)0.60 (0.52, 0.68)0.70 (0.53, 0.87)

0.85 (0.72, 0.99)

Fig 7 Mean deviation at apex,stratified by study design (human,cadaver, model).

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Group 2

Positioning method

ImplantsNobelNobelVISITVISITSimPlantTreonTreonVISITVISITSubtotal (I-squared = 84.1%, P = .000)

Drill holesIGI, DenXIGI, DenXIGI, DenXIGI, DenXPHANToMRobodentSimPlantSimPlantTreonVector VisionSubtotal (I-squared = 98.9%, P = .000)


0 1 2


0.80 (0.65, 0.95)1.10 (0.70, 1.50)0.57 (0.35, 0.80)0.52 (0.37, 0.67)1.45 (0.84, 2.06)1.20 (1.02, 1.38)1.10 (0.87, 1.33)0.85 (0.71. 0.99)0.90 (0.76, 1.04)0.90 (0.73, 1.06)

0.43 (0.31, 0.55)0.25 (0.14, 0.36)0.65 (0.36, 0.94)0.40 (0.32, 0.48)0.16 (0.08, 0.24)0.35 (0.26, 0.44)0.90 (0.76, 1.04)1.50 (1.31, 1.69)0.42 (0.37, 0.47)0.95 (0.92, 0.98)0.60 (0.36, 0.83)

0.74 (0.58, 0.90)

Fig 8 Mean deviation at entrypoint, stratified by positioningmethod (implants vs drill holes).

Positioning method

ImplantsNobelNobelVISITVISITSimPlantTreonTreonVISITVISITSubtotal (I-squared = 88.4%, P = .000)

Drill holesIGI, DenXIGI, DenXIGI, DenXRobodentSimPlantSimPlantTreonTreonTreonSubtotal (I-squared = 95.7%, P = .000)


0 1 2


1.20 (0.80, 1.60)0.90 (0.75, 1.05)0.78 (0.44, 1.12)1.40 (1.07, 1.73)2.99 (2.23, 3.75)0.75 (0.56, 0.94)0.80 (0.67, 0.93)1.20 (0.89, 1.51)0.65 (0.56, 0.74)1.03 (0.83, 1.23)

0.68 (0.52, 0.84)0.40 (0.24, 0.56)0.45 (0.36, 0.54)0.47 (0.38, 0.56)2.10 (1.83, 2.37)1.00 (0.83, 1.17)0.40 (0.32, 0.48)0.50 (0.42, 0.58)0.60 (0.52, 0.68)0.70 (0.53, 0.87)

0.85 (0.72, 0.99)

Fig 9 Mean deviation at apex,stratified by positioning method(implants vs drill holes).

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Jung et al

Tabl

e 5

C

linic

al S

tudi

es

No.

of

No.

of

impl

ants

A

ge

Mea

n Fo

llow

-up

Dyn

amic

im

plan

t N

o. o

fN

o. o

f S

tudy

N

o. o

f af

ter

rang

e ag

epe

riod

in

trao

p S

ingl

eP

art

C

omp

Impl

ant

Imm

com

plic

atio

nsim

plan

t pr

osth

etic

S

tudy

Year

de

sign

pati

ents

drop

out

(y)

(y)

(mo)

Sys

tem

nav

toot

hed

ent

eden

tM

axM

and

type

Flap

less

rest

intr

aop

failu

res

failu

res

1S

iess

egge

r et

al3

52

001

Pros

pect

ive

51

8N

RN

R0

Vect

or V

isio

n 2

10

11

10

Fria

lit 2

00

7N

RN

R2

Mis

chko

wsk

i 2

00

6Pr

ospe

ctiv

e14

25

01N

RN

R6

Med

3D

01

11

NR

NR

00

8 (1

.31

%)

NR

et a

l22

Pros

pect

ive

217

8N

RN

R6

coD

iagn

ostiX

01

11

NR

NR

00

NR

Pros

pect

ive

53

2N

RN

R6

Sim

Plan

t0

11

1N

RN

R0

0N

RPr

ospe

ctiv

e2

071

NR

NR

6R

obod

ent

11

11

NR

NR

00

4 (2

.96

%)

NR

Pros

pect

ive

18

64

NR

NR

6Ve

ctor

Vis

ion

21

11

1N

RN

R0

0N

R3

Witt

wer

et a

l3l

20

06

Pros

pect

ive

20

78

53

–75

61.4

4S

teal

th S

tatio

n 1

00

10

1An

kylo

s1

02

2N

RTr

eon

4W

ittw

er e

t al 3

62

00

7Pr

ospe

ctiv

e2

58

85

5–7

76

2.1

24

Ste

alth

Sta

tion

10

01

01

Anky

los

11

42

0Tr

eon

5W

ittw

er e

t al 17

20

07

RC

T16

64

56

–77

63

.40

Ste

alth

Sta

tion

10

01

01

Anky

los

11

0Tr

eon/

VIS

IT6

Witt

wer

et a

l 37

20

07

Pros

pect

ive

20

80

56

–77

64

.30

VIS

IT1

00

10

1An

kylo

s1

12

0N

R7

Fort

in e

t al1

82

00

6R

CT

60

15

21

9–8

25

00

.25

CAD

Impl

ant

00

11

NR

1N

RN

RN

RN

R8

van

Ste

enbe

rghe

2

00

5Pr

ospe

ctiv

e2

716

43

4–8

96

31

2N

obel

Gui

de0

00

11

0N

obel

1

10

00

et a

l38

Bio

care

9Fo

rtin

et a

l39

20

04

Pros

pect

ive

10N

RN

RN

R1

2C

ADIm

plan

t0

00

1N

R1

1N

R0

010

Fort

in e

t al4

02

00

3Pr

ospe

ctiv

e3

09

51

8–7

04

40

CAD

Impl

ant

00

11

NR

00

14N

RN

R1

1N

icke

nig

and

20

07

Pros

pect

ive

102

25

02

2–5

84

0.4

0co

Dia

gnos

tiX0

11

1N

R1

01

30

NR

Eitn

er19

12

San

na e

t al 21

20

07

Pros

pect

ive

30

18

33

8–7

45

62

6.4

Nob

elG

uide

00

01

Nob

el

11

NR

9 (4

.9%

)N

RB

ioca

re1

3Vr

ielin

ck e

t al2

02

00

3Pr

ospe

ctiv

e2

971

37

–71

56

.414

Sur

giG

uide

, 0

00

11

0N

obel

00

06

0M

ater

ialis

eB

ioca

reTo

tal

58

01

,24

35

6.1

7.7

56

917

34

09

64

2

nav

= n

avig

atio

n; P

art

eden

t =

par

tially

ede

ntul

ous;

Com

p ed

ent

= c

ompl

etel

y ed

entu

lous

; Max

= m

axill

a; M

and

= m

andi

ble;

Imm

res

t =

imm

edia

te r

esto

ratio

n; N

R =

not

rep

orte

d.

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Group 2

One randomized clinical trial compared pain expe-rience after implant placement with either an open-flap or a flapless surgical procedure.18 The resultsshowed a significant difference in pain measure-ments, with higher scores on the visual analog scalewith the open-flap surgery.

Very limited data are available regarding pros-thetic complication rates.

DISCUSSION

This review systematically assessed the literatureregarding accuracy and clinical performance of com-puter-assisted implant dentistry. In the dental litera-ture, 28 different image guidance systems aredescribed (Appendix, Table 8). Based on five includedclinical studies with a total of 506 implants usingcomputer-assisted implant dentistry, it was demon-strated that the mean annual failure rate was 3.36%(0% to 8.45%) after an observation period of at least12 months. As assessed by 19 clinical and preclinicalstudies, the accuracy at the entry point revealed amean error of 0.74 mm, with a maximum of 4.5 mm,while at the apex the mean error was 0.85 mm, with amaximum of 7.1 mm.

Clinical OutcomesIt is important to distinguish between clinical studiesreporting about dynamic navigation systems andabout static template-based guidance systems. Themajority of clinical studies have investigated the tem-plate-based guidance systems. The overall mean sur-vival rate of 96.6% after 1 year is considered to berather high. However, it is difficult to compare withother systematic reviews reporting implant survivalrates ranging from 95.4% (implant-supported fixedpartial dentures) to 96.8% (single-tooth implants)after 5 years, due to the lack of long-term data for theguided implant placements.1,2 Only one study isavailable with an observation period of more than 2years, and this reveals an implant survival rate of95.1% using a template-based guidance system and aprefabricated fixed prosthesis that was immediatelyloaded.21 To evaluate a new operation technique, it isimportant to know not just the implant survival ratebut also the practicality of the method in clinicalpractice. In 4.6% of the cases, intraoperative compli-cations or unexpected events were reported, includ-ing (1) interocclusal distances that were too limited toperform guided implant placement, (2) limited pri-mary stability of the inserted implants, or (3) the needfor additional grafting procedures. Since they are not

Table 7 Implant Failures, Follow-up Period and Annual Failure Rates

No. of Follow-upNo. of implants No. of % period Failure rate

Study Year Principle patients after dropout failures failures (mo) (events per 100 y)

Wittwer et al36 2007 Navigation 25 88 2 2.27% 24 1.1van Steenberghe et al38 2005 Guide 27 164 0 0.00% 12 0Fortin et al39 2004 Guide 10 NR 0 0.00% 12 0Sanna et al21 2007 Guide 30 183 9 4.92% 26.4 2.2Vrielinck et al20 2003 Guide 29 71 6 8.45% 14 7.2Total 121 506 17 3.36%Summary rate (95% CI) 2.4 (0.8–7.6)

NR = not reported.

Table 6 Systems Used in Studies Reporting onClinical Outcome

No. of No. of No. ofSystem studies patients implants

DynamicVISIT 2 28 122Treon 3 53 198Vector Vision 2 23 82Robodent 1 20 71

StaticSimPlant 1 5 32SurgiGuide 1 29 71Nobel Guide 2 57 347coDiagnostiX 2 123 325CADImplant 3 100 247Med3D 1 142 501

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always reported and there is no consistent definitionof a complication or an unexpected event, the datamust be interpreted with caution. In addition, the ratefor intraoperative complications and unexpectedevents was six times lower in flapless procedures. Itmight be possible that due to the lack of visualaccess, the complication rate in terms of implant mal-positioning and the need for additional grafting pro-cedures might be underestimated. However, thisfinding is only based on very limited data and shouldbe further evaluated in future study designs.

It is clearly beyond the intent or scope of thisreview to judge the benefits or merits of navigationversus template-based guidance systems. Only oneincluded study performed a comparison of the two.22

It was reported that the static approach has a clearadvantage due to the uncomplicated intraoperativehandling of the surgical templates and the less expen-sive equipment. Additionally, the process can beplanned by the surgeon and/or coworkers, or in coop-eration with the company which is responsible for thefabrication of the templates. In contrast, with thedynamic system the time spent on presurgical set-upand intraoperative application can be considered sig-nificantly longer, partly due to the navigation device.High purchase and maintenance costs of the systemshave to be taken into consideration.22 In general,today there seems to be a trend toward the static tem-plate-based guidance systems in dental implantology.

A consensus workshop organized by the EuropeanAssociation of Osseointegration raised several ques-tions, including which clinical indication wouldpotentially benefit from computer-assisted implantdentistry.23 The present systematic review includedstudies reporting about edentulous, partially edentu-lous, and single-tooth replacement cases. The major-ity of the included studies reported about edentulouscases. The reason may be the better cost-benefit ratioand the better acceptance of additional radiographicexaminations (CT scans) in patients with completelyedentulous ridges compared to single-tooth replace-ments. However, in the future, reductions in radiationdoses through improved radiographic techniques (ie,cone beam technique) and greater accuracy mightincrease the number of indications for computer-assisted implant placement.

Accuracy Computer-assisted implant dentistry has often beenrecommended for flapless procedures and forimplant placements in situations with a limitedamount of bone or proximity to critical anatomicalstructures. Hence, it is of utmost importance to knowthe accuracy of the dynamic and static systems avail-able for implant dentistry. In this systematic review,

the accuracy in computer-assisted implant dentistrywas assessed by including various methods of evalu-ation (mostly CT, but also direct measurements ofsectioned models or registration of the handpieceposition), and by including preclinical and clinicalmodels. In general, the accuracy was better in studieswith models and cadavers than in studies withhumans. This can be explained by better access, bet-ter visual control of the axis of the osteotomy, nomovement of the patient, and no saliva or blood inthe preclinical models. There was no significant differ-ence between cadavers and models; therefore, theinfluence of the material (bone versus acrylic) mightbe negligible for testing the accuracy in a preclinicalmodel. However, it is recommended that the accuracybe assessed in clinical situations. This recommenda-tion is supported by the results of this review, inwhich the highest number of deviations wererevealed in human studies compared to preclinicalmodels (see Table 7). In addition, it is more importantto report the maximum deviation, which is crucial toprevent damage of anatomical structures, than toreport the mean deviation.

One included study using a static template-basedsystem reported a maximum deviation of 4.5 mm atthe entry point.24 This is by far the highest value fordeviation reported in all studies in the presentreview. The authors proposed that this differencemight result from movements of the surgical guideduring implant preparation. They suggested furtherimprovements to provide better stability of the tem-plate during surgery when unilateral bone-supportedand non–tooth-supported templates are used.24

In the present systematic review, the overall meanerror at the entry point was 0.74 mm. To interpret thisvalue it is important to know the accuracy of manualimplant preparation.Two preclinical studies performedon acrylic models compared the accuracy of twodynamic navigated systems with conventional implantpreparation.16,25 In one study, the reported maximumerror at the entry point ranged from 0.8 to 1 mm forthe conventional insertion and was 0.6 mm for thenavigated insertion.25 The other study reported amean error at the entry point of 1.35 mm for manualimplantation and 0.35 to 0.65 mm (RoboDent and IGIDenX Systems) for dynamic navigated implant place-ment. These values are in accordance with the meanerror at the entry point in preclinical models revealinga difference of 0.6 mm in the present review. Bothstudies demonstrated a statistically significantly higheraccuracy for the navigated systems compared to themanual implant placement.16,25 However, this compari-son was only performed on dynamic navigated sys-tems, and no data for static template-based systemsare available. This is even more important because the

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dynamic systems in the present systematic reviewprovided greater accuracy than the static systems. Thisdifference might be explained by the fact that statictemplate-based systems were more often used clini-cally rather than in preclinical models, which haveprovided better accuracy.

Because of different study designs (human versuscadaver or model, drill holes versus implants, differentevaluation methods), it is not possible to identify onesystem as superior or inferior to others.

A series of errors during the entire diagnostic andoperative procedure might contribute to an accumu-lation of minor errors, leading to larger deviations ofthe implant position. The reproducibility of the tem-plate position during radiographic data acquisitionand during implantation is a delicate issue, especiallyin edentulous patients.

In addition, it is important to realize that computer-assisted implant surgery is a new field of researchthat is undergoing rapid development and improve-ments in clinical handling properties and accuracy.Hence, the systems used today in clinical practicemight demonstrate greater accuracy and might havesolved some of the above-mentioned problemsencountered with earlier versions, but these data arenot yet available in the dental literature. This rapidadvancement in computer technology should beconsidered when evaluating older reports of varioussystems, since those that were tested may not bearmuch similarity to current offerings.

CONCLUSION

It is concluded from this systematic literature searchthat a large number of different computer-assistedguided implant systems are available today in clinicalpractice. Differing levels and quantity of evidencewere noted to be available, revealing a high meanimplant survival rate of 96.6% after only 12 months ofobservation in different clinical indications. In addi-tion, the mean percentage of intraoperative compli-cations and unexpected events was 4.6%. Theaccuracy of these systems depends on all cumulativeand interactive errors involved, from data-set acquisi-tion to the surgical procedure. The meta-analysis ofall preclinical and clinical studies revealed a totalmean error of 0.74 mm at the entry point and 0.85mm at the apex. Future long-term clinical data arenecessary to identify clinical indications and to justifyadditional radiation doses, efforts, and costs associ-ated with computer-assisted implant surgery. There isnot yet evidence to suggest that computer-assistedsurgery is superior to conventional procedures interms of safety, outcomes, morbidity, or efficiency.

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20. Vrielinck L, Politis C, Schepers S, Pauwels M, Naert I. Image-based planning and clinical validation of zygoma and ptery-goid implant placement in patients with severe bone atrophyusing customized drill guides. Preliminary results from aprospective clinical follow-up study. Int J Oral Maxillofac Surg2003;32:7–14.

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28. van Steenberghe D, Naert I, Andersson M, Brajnovic I,Van Cley-nenbreugel J, Suetens P. A custom template and definitive pros-thesis allowing immediate implant loading in the maxilla: Aclinical report. Int J Oral Maxillofac Implants 2002;17:663–670.

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32. Wanschitz F, Birkfellner W, Watzinger F, et al. Evaluation of accu-racy of computer-aided intraoperative positioning ofendosseous oral implants in the edentulous mandible. ClinOral Implants Res 2002;13:59–64.

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34. Wagner A, Wanschitz F, Birkfellner W, et al. Computer-aidedplacement of endosseous oral implants in patients after abla-tive tumour surgery: Assessment of accuracy. Clin OralImplants Res 2003;14:340–348.

35. Siessegger M, Schneider BT, Mischkowski RA, et al. Use of animage-guided navigation system in dental implant surgery inanatomically complex operation sites. J Craniomaxillofac Surg2001;29:276–281.

36. Wittwer G, Adeyemo WL, Wagner A, Enislidis G. Computer-guided flapless placement and immediate loading of fourconical screw-type implants in the edentulous mandible. ClinOral Implants Res 2007;18:534–539.

37. Wittwer G, Adeyemo WL, Schicho K, Figl M, Enislidis G. Navi-gated flapless transmucosal implant placement in themandible: A pilot study in 20 patients. Int J Oral MaxillofacImplants 2007;22:801–807.

38. van Steenberghe D, Glauser R, Blomback U, et al. A computedtomographic scan-derived customized surgical template andfixed prosthesis for flapless surgery and immediate loading ofimplants in fully edentulous maxillae: A prospective multicenterstudy. Clin Implant Dent Relat Res 2005;7(suppl 1):S111–S120.

39. Fortin T, Isidori M, Blanchet E, Perriat M, Bouchet H, Coudert JL.An image-guided system-drilled surgical template andtrephine guide pin to make treatment of completely edentu-lous patients easier: A clinical report on immediate loading.Clin Implant Dent Relat Res 2004;6:111–119.

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APPENDIX

Review of Systems for Computer-AssistedImplant DentistryFrom information derived from review of the litera-ture, combined with Internet searches and additionalcommercial sources, a compilation of computer-based products for implant surgery was created. It isimportant to clarify and distinguish the types of sys-tems based on very specific definitions published inthe Glossary of Oral and Maxillofacial Implants (GOMI;Chicago: Quintessence, 2007).

• Computer-aided design/Computer-assisted manu-facture (CAD/CAM): Computer technology used todesign and manufacture various components.

• Image guidance: General technique of using pre-operative diagnostic imaging with computer-basedplanning tools to facilitate surgical and restorativeplans and procedures.

• Imaging guide: Scan to determine bone volume,inclination and shape of the alveolar process, andbone height and width, which is used at a surgical lsite.

• Surgical navigation: Computer-aided intraopera-tive navigation of surgical instruments and opera-tion site, using real-time matching to the patients’anatomy. During surgical navigation, deviationsfrom a preoperative plan can be immediatelyobserved on the monitor.

• Computer-aided navigation: Computer systems forintraoperative navigation, which provide the sur-geon with current positions of the instruments andoperation site on a three-dimensional recon-structed image of the patient that is displayed on amonitor in the operating room. The system aims totransfer preoperative planning on radiographs orcomputed tomography scans of the patient, in real-time, and independent of the position of thepatient’s head.

• Surgical template: Laboratory-fabricated guidebased on ideal prosthetic positioning of implantsused during surgery. Also called surgical guide.

• Three-dimensional guidance system for implantplacement: A computed tomography (CT) scan isperformed to provide image data for a three-dimensional guidance construct for implant place-ment. A guide is a structure or marking that directsthe motion or positioning of something, thus inimplant dentistry this term should not be used as asynonym for surgical implant guide. A radiographicguide is rather used as a positioning device in intra-oral radiography.

For the purpose of this consensus review, someGOMI definitions were clarified:

• Computer-guided (static) surgery: Use of a staticsurgical template that reproduces virtual implantposition directly from computerized tomographicdata and does not allow intraoperative modifica-tion of implant position.

• Computer-navigated (dynamic) surgery: Use of asurgical navigation system that reproduces virtualimplant position directly from computerized tomo-graphic data and allows intraoperative changes inimplant position.

All systems incorporate planning of implant posi-tions on a computer, using various software tools.These plans are then converted into surgical guidesor used in other positioning systems in a variety ofmethods. In general, these implant positioningdevices can be categorized into “static” and“dynamic” systems. “Static” systems are those thatcommunicate predetermined sites using “surgicaltemplates” or implant guides in the operating field.Therefore, “static systems” and “template-based sys-tems” are synonymous. Alterations to implant posi-tion or deviations from the prefabricated templatecan be accomplished “free-hand”.

Dynamic systems communicate the selectedimplant positions to the operative field with visualimaging tools on a computer monitor, rather than intra-oral guides.The dynamic systems include “surgical navi-gation” and “computer-aided navigation” technologies.With these, the surgeon may alter the surgical proce-dure and implant position in real time using theanatomical information available from the preoperativeplan and CT scan. Since the surgeon can see an avatarof the drill in a three-dimensional relationship to thepatient’s previously scanned anatomy during surgery,modifications can be accomplished with significantlymore information. In essence, the navigation systemprovides a virtual surgical guide or template that maybe altered when conditions indicate.

Table 8 is a compilation of currently availableimage guidance systems and those that appear to bein development or have some scientific publicationsavailable for review. The commercially available sys-tems have been divided into two categories. The firstsection represents 22 software systems that are avail-able for radiographic diagnosis and also generallyprovide for fabrication of surgical guides. The systemsfall into the category of “three-dimensional guidancesystems for implant placement,” permitting implantplanning from patient CT or CBCT scans. These prod-ucts offer computer-based diagnostic and planningtools that permit enhancement, manipulation, andanalysis of a patient’s digital scan.

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Planning information can remain stored on a com-puter in digital files for visual review or can be sent toa manufacturing facility to create three-dimensionalmodels of the stored images. Most systems generateinformation to fabricate a surgical guide once appro-priate surgical planning has been completed. Thismanufacturing process, generically called CAD/CAM,uses either rapid prototyping technologies such as3D printing and stereolithography or “computer-dri-ven drilling (CDD)” to create anatomical models.41

For surgical planning, implant avatars are posi-tioned into the scanned images using software tosimulate surgical placement. Once a satisfactory planis approved and saved, CAD/CAM technology is usedto produce a customized surgical template or guide.Depending on the manufacturer, guides can beindexed to available surrounding teeth, mucosal con-tours, or bony contours. Some manufacturers addi-tionally offer prosthesis fabrication, combining thedigital information with dental prosthetics.

Table 8 Currently Available Systems in Computer-Assisted Implant Dentistry

Virtual implant Drill guide Application Website Company planning Guide production Notes

Surgical guides (static)3D-Doctor www.ablesw.com Able Software, USA yes Models CDDBiodental Models www.biomodel.com BioMedical Modeling, USA yes Models RPImplant3D www.implant3d.com Media Lab, Italy yes Models RP Create stereolitho-

graphic modelCyrtinaGuide www.cyrtina.nl Oratio, Netherlands yes Surgical guide RPDentalSlice www.bioparts.com.br BioParts, Brazil yes Surgical guide RPEasyGuide www.keystonedental.com Keystone Dental, USA yes Surgical guide CDDGPIS GPI Technology, Germany Simplant/ Surgical guide CDD

IVSILS www.tactile-tech.com Tactile Technologies , Israel yes Surgical guide Custom Under development

drilling tubesILUMA DigiGuide www.imtec.com IMTEC, USA yes Surgical guide RP Specific for MDI

implantsImpla 3D www.sdginnovations.com Schutz Dental Group yes Surgical guide CDDInVivoDental www.anatomage.com Anatomage , USA yes Surgical guide CDD Under developmentAnatoModel www.anatomage.com Anatomage, USA yes Surgical guide CDD See EasyGuideImplant 3D www.med3d.de Med3D, Switzerland yes Surgical guide CDDImplant Master www.ident-surgical.com I-Dent Imaging, USA yes Surgical guide RPScan2Guide www.ident-surgical.com I-Dent Imaging, USA yes Surgical guide RP “Light” version of

Implant MasterOndemand3D www.cybermed.co.kr Cybermed, Korea yes Surgical guideImplantOralim Oral Implant www.medicim.com Medicim, Belgium yes Surgical guide RP Marketed by Planning System Nobel Biocare NobelGuide www.nobelguide.com Nobel Biocare, USA yes Surgical guide CDD Specific for (Medicim Oralim) Nobel Biocare implantsSimplant Master www.materialise.com Materialise Dental, Belgium yes Surgical guide RPSimplant Planner www.materialise.com Materialise Dental, Belgium yes Surgical guide RPSimplant Pro www.materialise.com Materialise Dental, Belgium yes Surgical guide RPVIP www.implantlogic.com Implant Logic Systems, USA yes Surgical guide CDD Marketed by BioHorizons

Navigation systems (dynamic)VoNavix www.codiagnostix.de IVS Solutions, Germany yes Navigation NoneMona-Dent www.imt-web.de IMT, Germany yes Navigation NoneNaviBase,NaviDoc & www.robodent.com Robodent, Germany yes Navigation NoneNaviPadTreon (medical) www.medtronicnavigation.com Medtronic Navigation, USA yes Navigation None Not commercially

availableIGI www.image-navigation.com Image Navigation, Israel yes Navigation None Formerly DenX, IncVISIT University of Vienna, Austria Navigation None not commercially

available

RP = rapid prototyping; CDD = computer-driven drilling.

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Advantages of these systems may include generalfamiliarity with the use of surgical guides based onlong-established procedures. A high degree of preci-sion may be obtained, particularly when guides incor-porate graduated dimensions of drilling sleeves toguide increasing diameters of drills. Some systemsprovide two-dimensional (mesiodistal and buccolin-gual) guidance, while others also incorporate depthcontrol. The precision of the surgical templatesdepends on the accuracy of the scan and the fit ofthe device during use. Some manufacturers requirecasts of the patients’ arches or teeth to insure accu-rate fit, while others create the guides from thescanned images and contours. Difficulties can arisewhen patients have poor edentulous ridge form orloose teeth, or extractions are anticipated, sinceanatomical landmarks required for surgical guide sta-bilization could move or change. Several strategies toovercome these problems have been devised. As pre-viously noted, some manufacturers fabricate provi-sional or final restorations from the digital plans, butthere are too few long-term data to permit consider-ing this a routine or accepted procedure.

The final group of devices includes six surgicalnavigation systems, four of which are commerciallyavailable. Surgical navigation systems require thatsensors be attached to both the patient and the sur-gical handpiece. These sensors transmit three-dimen-sional positional information to a camera or detectorthat allows the computer to instantaneously calculateand display the virtual position of the instrumentsrelative to the stored image of the patient’s anatomy.

An analogous technology is the global positioningsystem used for personal transportation, which simi-larly uses a satellite to track an individual’s movementsagainst a previously stored map. During surgery, thesurgeon typically watches the computer monitor inaddition to, or instead of, the surgical site to monitorpositional accuracy. In medicine, this is similar to endo-scopic or laparoscopic procedures, where the surgicalsites are obscured, requiring viewing on a monitor.

An advantage of navigation systems is that thesurgical plan can be altered or modified while retain-ing the “virtual vision” of the technology. The surgeoncan either move the virtual implant on the plan orignore the plan completely and use the navigationsystem to contemporaneously visualize the patient’sanatomy. This permits the surgeon to steer aroundobstacles, defects, or conditions that were not appar-ent on the presurgical scan. Similar technology hasbeen safely and effectively used in other branches ofmedicine, including neurosurgery, spinal surgery, andcardiac surgery. In addition to the stability problemsnoted for surgical guides, complications and difficul-ties can arise with navigation if the sensors are notprecisely and firmly attached to the patient or hand-piece. To date, restorations have not been CAD/CAMproduced from planning files of the navigation sys-tems. It is possible to do a sham procedure on dentalcasts, so that a dental laboratory could prefabricaterestorations for immediate-loading procedures priorto implant placement. As with restorations plannedfrom computer-generated surgical guides, this tech-nique has not been adequately investigated.

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