E.A.O. Guidelines for the use of Diagnostic Imaging in Implant Dentistry. A consensus workshop organized by the European Association for Osseointegration in Trinity College Dublin

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David Harris
Daniel Buser
Karl Dula
Kerstin Gröndahl
David Harris
Reinhilde Jacobs
Ulf Lekholm
Richard Nakielny
Daniel van Steenberghe
Paul van der Stelt
Authors’ affiliations:
Daniel Buser, Department of Oral Surgery,
University of Berne, Freiburgstrasse 7, CH-
30110 Berne, Switzerland
Karl Dula, Dental School, University of Berne,
Freiburgstrasse 7, CH-30110 Berne, Switzerland
Kerstin Gröndahl, Department of Oral and
Maxillo-Facial Radiology, Sahlgrenska Academy,
Göteborg University, PO Box 459,SE40503
Göteborg, Sweden
David Harris, School of Dental Science, Trinity
College Dublin. Lincoln Place, Dublin 2. Ireland
Reinhilde Jacobs, Oral Imaging Cluster, Faculty
of Medicine, Catholic University Leuven,
Kapucijnenvoer 7,B-3000 Leuven Belgium
Ulf Lekholm, Branemark Kliniken, Tandvarden
and Faculty of Dentistry, Goteborgs Universtet,
Medicinaregatan 12,S-413 90 Goteborg, Sweden
Richard Nakielny, Dept of Medical Imaging and
Medijcal Physics (CT/MR scanning), Royal
Hallamshire Hospital, Sheffield, S10 2JJ, UK
Daniel van Steenberghe, Catholic University
Leuven, Department of Periodontology,
Kapucijnenvoer 7,B–3000 Leuven Belgium
Paul van der Stelt, Department of Oral and
Maxillofacial Radiology. ACTA Louwesweg 1,
1066 EA Amsterdam, Netherlands
Date:
Accepted 15 April 2002
To cite this article:
Harris D, Buser D, Dula K, Gröndahl K, Harris D,
Jacobs R, Lekholm U, Nakielny R, van Steenberghe
D, van der Stelt P . E.A.O. Guidelines for the use of
Diagnostic Imaging in Implant Dentistry
Clin. Oral Impl. Res, 13,2002;566–570
Copyright CBlackwell Munksgaard 2002
ISSN 0905-7161
566
E.A.O. Guidelines for the use of
Diagnostic Imaging in Implant
Dentistry
A consensus workshop organized by the European
Association for Osseointegration in Trinity College
Dublin.
Introduction
Diagnostic imaging is an essential compo-
nent of implant treatment planning. Until
the late 1980s, conventional radiographic
techniques such as intraoral, cephalo-
metric and panoramic views have been the
accepted standard.
Since then, developments in cross-sec-
tional imaging techniques, such as spiral
tomography and reformatted computerised
tomograms, have become increasingly
popular in the preoperative assessment and
planning of implant patients. Additionally,
proprietary software has become available
that will allow clinicians to manipulate
digital images on a PC.
The Board of the E.A.O. is concerned that
the rapid adoption of these sophisticated
techniques into routine practice might lead
to a significant increase in the radiatio n bur-
den of patients without a proper risk benefit
analysis. The directive of the council of the
European Communities (97/43 EURA-
TOM, Official Journal of the European
Communities. L 180,9.7.1997,pp22–27)
makes extensive recommendations about
the responsible use of ionizing radiation in
medicine. Article 3of these directives under
Justification 1. states that:
‘’Medical exposure ... shall show a suf-
ficient net benefit, weighing the total po-
tential diagnostic or therapeutic benefits it
produces ... Against the individual detri-
ment that the exposure might cause, tak-
ing into account the efficacy, benefits and
risks of available alternative techniques
having the same objective but involving no
or less exposure to ionizing radiation.
The Board felt it would be timely to for-
mulate guidelines that would help its
members ensure a responsible and ethical
application of these sophisticated tech-
niques to implant dentistry.
A2-day closed workshop was organised
under the auspices of the E.A.O. at Trin-
ity College Dublin, May 12th and 13th
2000.
Expert participants in the clinical and
radiology fields were invited on the bases
of their established scientific contri-
butions to the field, specialist knowledge,
significant clinical experience and rel-
evant activities in their academic insti-
tutions and abilities to express them-
selves in English. Participants were re-
quired to reach a consensus on relevant
questions and guidelines.
The aim of these guidelines is to pro-
vide recommendations in various clinical
situations that will ensure essential diag-
nostic information is obtained with as
low as reasonably achievable (ALARA
principle) radiation exposure. They also
draw attention to the special responsibil-
ities and knowledge that is a prerequisite
for the application of these techniques
Dr David Harris
Chairman
A. Clinical Considerations
1. What radiological information does a surgeon
require when planning for implant surgery and
at what stage should it be obtained?
In investigating an implant site, a surgeon
requires information on bone volume and

Harris . EAO Guidelines
quality, topography and the relationship to
important anatomical structures, such as
nerves, vessels, roots, nasal floor, and sinus
cavities.
This information is obtained with a clin-
ical examination and appropriate conven-
tional radiographs. The decision to proceed
to cross-sectional imaging must be based
on clearly identified needs and the clinical
requirements of the clinicians involved.
Implant failure may be related to poor
bone quality at the implant site. Infor-
mation about bone quality can be obtained
preoperatively based on radiographic im-
ages and partly during the surgical per-
formance (Bahat et al.1993; Bassi et al.
1999; Ulm et al.1999).
2. What type of clinical situations might
potentially benefit from cross-sectional
imaging?
1. When reference to such images can help
minimize the risk of damage to import-
ant anatomical structures.
2. To provide more information in border-
line clinical situations where there is
limited bone height and/or bone width
available for successful implant treat-
ment.
3. To improve implant positioning and ax-
ial direction that will optimize bio-
mechanical, functional and aesthetic
treatment results. The diagnostic infor-
mation can be enhanced by the use of
appropriate radiopaque markers or re-
storative templates. However, this infor-
mation cannot be transferred exactly to
the surgical site as long as no intraopera-
tive navigation is used (Naitoh et al.
2000).
3. Who should decide whether a patient
requires cross-sectional imaging?
Clinicians should decide on the basis of the
clinical examination and treatment re-
quirements, and on information obtained
from conventional radiographs whether or
not cross-sectional imaging will be of
benefit.
If the patient is to be referred then a radi-
ologist with specialised knowledge in the
field should decide on the appropriate cross-
sectional imaging techniques based on the
information provided by the clinician.
Circumstances may dictate that it is the
clinician who must decide. Clinicians must
clearly indicate the reasons for requesting
567 |Clin. Oral Impl. Res. 13,2002 /566–570
the investigations and provide the radiol-
ogist with sufficient information to allow
the production of accurate and relevant im-
ages of good quality. It is the duty of the cli-
nician to understand the fundamental prin-
ciples of cross-sectional imaging and to be
capable of interpreting the images.
The technique chosen should provide
the required diagnostic information with
the least radiation exposure to the patient.
B. Radiological Considerations
1. What imaging modalities are available for
investigation of potential implant sites?
Standard radiographic imaging techniques
are intraoral, panoramic and profile (lat-
eral) radiographs. In certain special indi-
cations, cross-sectional imaging [i.e. spiral
tomography and multiplanar reformatted
computed tomography (CT)] may be
necessary.
2. What is the recommended technique
performing these imaging modalities, and what
is the resulting radiation dose?
Tab le 1delineates the recommended tech-
nique for each imaging modality together
with the resulting maximum radiation
dose acceptable. It is essential that the AL-
ARA (as low as reasonably achievable)
principle is adhered at all times. This may
result in significantly lower doses in cer-
tain circumstances.
Digital radiography might reduce the
dose even further.
3. What is the biological risk from the dose
incurred in each of the techniques?
The use of radiation involves a certain
amount of risk. To assess the significance of
this risk it is important to set it in context
with other commonly encountered risk fac-
tors (NRPB 1998). A few examples are:
A: Annual risk of death in the UK
Smoking 10 cigarettes 1:200
per day
Heart disease 1:300
Accident in the home 1:15,000
Accident on the road 1:17,000
B: Radiation exposure in context
The annual dose averaged over the whole
European population, is about 3mSv per
person. However, 85%ofthisisdueto
natural background radiation, and only
14% from medical and dental radiation.
The International Commission on
Radiological Protection (ICRP) has esti-
mated the risk per mSv as 1in 20 000.
For younger age groups the risk is esti-
mated to be twice as high.
Based on the above estimated values,
the risk for the various imaging modalities
is as follows:
Intraoral radiography
Frontal 1:10,000,000
Premolar 1:5,000,000
Molar 1:3,000,000
Full mouth survey 1:476000
Panoramic imaging 1:667000
Cephalometric lateral skull
With wedge form
collimation ⬍1:2,000,000
Computed
tomography ⬍1:40,000/jaw
Spiral tomography
Maxilla ⬍1:2,000,000/cut
Mandible ⬍1:4,000,000/cut
4. What is the recommended imaging modality
for different clinical situations
Tab le 2a provides an overview of the rec-
ommended standard imaging modalities to
be used.
Tab le 2b shows the options of additional
cross-sectional imaging. This applies to
those cases where more information is re-
quired after appropriate clinical examina-
tion and standard radiographic techniques
have been performed
The choice of techniques is based on the
lowest dose giving the required diagnostic
information. For example, the assessment
of a single tooth gap requires approximate-
ly 25 times less radiation using one spiral
cross-sectionals tomogram as compared to
a CT examination.
If the suggested cross-sectional imaging
modality is not available, the alternate
cross-sectional modality may be used, but
this may result in a higher dose and/or
lower diagnostic quality.
5. What are the mechanisms of ensuring on-
going quality assurance?
Proper training of staff performing these
procedures is required. In addition, they
must also receive continuing education at
regular intervals to maintain the quality of
the images produced.
Adherence to recommended equipment-

Harris . EAO Guidelines
Tab le 1 . Recommended techniques and associated effective doses (E)
Modality Recommended Technique E (mSv)
Intraoral radiography F-speed film Frontal 0.002/radiograph
Rectangular collimation Premolar
Paralleling technique 0.004/radiograph
Upper jaw: palate horizontally Molar 0.006/radiograph
Lower jaw: occlusal plane horizontally Full mouth survey (20 films): .04/survey
Panoramic Proper collimation ⬍0.003
imaging Rare earth screen
Proper patient positioning:
Meato-orbital plane horizontal
Head symmetrical
Lower jaw protruding
Lower and upper incisors inside the image l ayer
Neck extended
Dorsum of tongue in contact with hard palate during exposure
Cephalometric Proper collimation ⬍0.01
lateral skull Rare earth screen
Median plane of head vertical
Computed KV: 120 ⬍0.5/jaw
tomography mAs: ⬍100
Slice thickness: 1 mm
Pitch: 1–1.5
Suggested window: 1250; level: 250
Maxilla: slices parallel with hard palate f rom alveolar
crest up to/including hard palate.
Mandible: slices parallel with mandibular base
in region of interest.
Dose reduction possible by reducing number of slices,
increasing pitch and/or lowering mAs.
Conventional Rare earth screen *Maxilla ⬍0.03/cut
tomography** As few cuts as possible.
Proper positioning: *Mandible ⬍0.02/cut
The tomographic plane perpendicular to the hard
palate (maxilla) and the mandibular canal ( mandible)
and at the same time perpendicular to the tan gent of
the alveolar process in the region of intere st.
*14 cuts per jaw ΩE (mSv) 0.52/jaw
**Table 1. Information derived from the following sources: British O rthodontics Standards Working Party 1994, Dula et al. 19 96, 2001; Ekestubbe et al. 1999; Price 1995;
Syriopoulos et al. 2001, Velders et al. 2000, White 1992
Table 2a. Recommended standard radiographic techniques
Intra-oral radiography Panoramic imaging **Cephalo-metric lateral skull
MAXILLA
Single tooth X
Partially dentate X X
Edentulous X X
MANDIBLE
Single tooth X
Partially dentate X X
Edentulous Axial, X X
occlusal view*
*For Brånemark Novum cases only.
**Cephalo-metric Wedge form collimation
The Brånemark Novum Protocol for Same-Day Teeth; a global perspectiv e.
Edited by Per-Ingvar Brånemark for Quintessence books in 2001.
maintenance policies and regular quality
assurance procedures is also required to en-
sure the equipment produces the best poss-
ible images.
An effective method of identifying weak-
568 |Clin. Oral Impl. Res. 13,2002 /566–570
points in image production is film-reject
analysis.
Finally, an equipment replacement pol-
icy should be in place to ensure that equip-
ment is up to standard.
C. Diagnostic benefits
What are the potential diagnostic benefits of
cross-sectional imaging?
(a) Pre-operative assessment to identify
bone volume, jaw topography, bone
structures, location of important ana-
tomical landmarks, etc.
(b) Treatment planning to identify optimal
locations of implant sites in relation to
available anatomical conditions for best
aesthetics, function and loading con-
ditions. The techniques can also be
helpful as part of the pre-operative plan-
ning for various augmentation proto-
cols.
(c) Post-operative monitoring cross-sec-
tional imaging is not a part of the rou-
tine protocol of post-operative examina-
tions, unless there is a need for assess-
ments in situations where some kind

Harris . EAO Guidelines
Table 2b. Recommended cross-sectional imaging modalities; special indications
Spiral tomography Computed tomography
MAXILLA
Single tooth
a. incisive canal 1–2 2-mm cuts
b. descent of maxillary sinus 1 2-mm cut
c. clinical doubt about shape of alveolar r idge 1 2-mm cut
Partially dentate
a. descent of maxillary sinus Small areas
(ⱕ4 4-mm cuts per quadrant) Multiple regions
b. clinical doubt about shape of alveolar r idge
Edentulous
a. descent of maxillary sinus Specific sites targeted
(ⱕ4 4-mm cuts per quadrant) Multiple regions
b. clinical doubt about shape of alveolar r idge
MANDIBLE
Single tooth
a. clinical doubt about position of mandib ular canal 1 2-mm cut
b. clinical doubt about shape of alveolar r idge
Partially dentate
a. clinical doubt about position of mandib ular canal or mental foramen 1–4 4-mm cuts per quadrant Multiple regions
b. clinical doubt about shape of alveolar r idge
Edentulous
a. severe resorption 1–2 4-mm cuts per sextant Multiple regions
b. clinical doubt about shape of alveolar r idge
c. clinical doubt about position of mandib ular canal if posterior
implants are to be placed
of complications have occurred, such as
nerve damage, postoperative infections
in relation to nasal and/or sinus cavities
close to implants.
D. Recommendations for the use
of cross-sectional imaging in
implant dentistry
Single Tooth Implant Sites
If the clinical examination indicates there
is sufficient bone width and recommended
standard radiographic examination reveals
adequate bone height and space, no ad-
ditional imaging is required.
Additional cross-sectional imaging may
be required when an implant site lies in
close relationship to nerve canals as occurs
in the posterior mandible and the maxil-
lary central incisors. It also may be of bene-
fit in investigating defect sites to allow for
more precise treatment planning.
Edentulous Maxilla
In many cases, clinical examination in con-
junction with recommended standard
radiographs will provide sufficient infor-
mation on the available bone volume.
Additional cross-sectional imaging
569 |Clin. Oral Impl. Res. 13,2002 /566–570
may be required to determine the adequacy
of the available bone volume and the
need for bone augmentation/grafting pro-
cedures.
Cross-sectional images can also help in
the planning and predictability of pros-
thetic results that involve a fixed pros-
thesis and in the transfer of this infor-
mation to guide the surgeon in implant po-
sitioning.
Special techniques such as zygomatic
implants may also dictate the need for ad-
ditional imaging.
Partially Edentulous Maxilla
Clinical examination in conjunction with
recommended standard radiographs will
form the basis for treatment planning and
indicate if further cross-sectional imaging
is required.
Assessment of bone volume and top-
ography, the position of adjacent anatomi-
cal structures and the need for restorative
planning particularly in the aesthetic
zone may indicate a need for additional
imaging.
Edentulous Mandible
In almost all cases, clinical examination in
conjunction with recommended standard
radiographs will provide sufficient infor-
mation for treatment planning. In certain
circumstances, involving extreme atrophy
or unusual anatomy, additional imaging
may be beneficial.
Partially Edentulous Mandible
Clinical examination in conjunction with
recommended standard radiographs will
form the basis for treatment planning and
indicate if further cross-sectional imaging
is required.
When implants are to be placed in prox-
imity to the inferior alveolar nerve, cross-
sectional images can provide useful ad-
ditional information on the available bone
volume and shape in relation to the posi-
tion of the nerve canal.
Future developments
There is an urgent need enhance and im-
prove the knowledge and skills of dento-
maxillofacial radiology in undergraduate,
postgraduate and continuing education
programmes. Radiation protection aspects
should be emphasized.
It is also of great importance that clini-
cians are aware of the need for communi-
cation between them and the radiologist
before any radiographic examination is per-

Harris . EAO Guidelines
formed and that the clinician clearly state
which diagnostic information is required.
Communication among clinicians and
experts for second opinion and/or interac-
tion during planning of oral implants could
also benefit from data transfer through any
type of network.
Clinicians in the oral field should ideally
always choose the optimal imaging tech-
nique rather than the one available in their
own practice/centre.
Considering the presumed relationship
between implant failure and poor bone
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