1) The document discusses various imaging modalities used in oral implantology such as periapical radiography, panoramic radiography, tomography, cone beam computed tomography, and computed tomography. 2) Key factors in selecting a radiographic technique include evaluating bone quantity and quality, relationship to vital structures, cost, and radiation exposure. 3) Advanced imaging such as cone beam computed tomography provides high resolution cross-sectional views with low radiation exposure and is useful for implant planning and assessment of vital structures.

1. Imaging in oral implantology
Anish Amin

2. Digital
radiography
Cone beam
volumetric
tomography
Imaging of vital
structures
Phases
of imaging
Introduction
Interactive
computed
tomography.
Periapical
radiography
Conclusion
References
Panoramic
radiography
Imaging
modalities.
Tomography
&
computed tomography
Diagnostic
templates
CONTENTS

3. › The widespread use of dental implants in partially and
completely edentulous patients has brought about a need
to preoperatively depict and quantify the accurate bone
height and contour and location of vital anatomic structures
by radiographic examination
› Multiple factors influence the selection of radiographic
technique(s) for a particular case, including cost,
availability, radiation exposure, and case type.
› Diagnostic imaging techniques must always be interpreted
in conjunction with a good clinical examination.
› The decision is a balance between these factors and the
Introduction

4. Phases of imaging

5. 1) Pre-surgical implant imaging
oTo assess the overall status of the
remaining dentition
oTo identify and characterize the
location and nature of the
edentulous regions, particularly to
determine the quantity , quality
and angulations of boneo To determine the relationship of
critical structures to the proposed
implant site
o To detect regional anatomic

6. 2) Surgical & intraoperative implant
imaging
› Evaluates the sites during
and immediately after
surgery
› Assist in the optimal
position and orientation of
dental implants
› To evaluate the healing
and integration phase of
implant surgery

7. 3) Post-prosthetic imaging
› To evaluate the long-term maintenance of
implant rigid fixation and function
› To assess the Crestal bone levels around
each implant
› To evaluate the implant complex

8. Imaging modalities
› The decision to image the patient is based on
the patients clinical needs and its availability.
› Imaging modalities can be:
Analog / Digital
imaging modalities
Two-dimensional /
Three –dimensional
imaging modalities

9. Periapical radiography
Indications:
›Evaluation of small
edentulous spaces ,
Eg: in case of single
tooth replacement
›Alignment and
orientation of implants
during surgery
›Recall/maintenance
evaluations
Intraoral periapical
radiograph displaying the
implant placed at the site of
11, and its relation to

10. oAmount of bone loss and peri-
implantitis can be visualized
oSubtle variations in bone activity is
clearly seen
oMinimal magnification with high
resolution
oThey are easy to obtain in the dental
Advantage

11. Disadvantages
oThey are susceptible to
unpredictable magnification of
anatomic structures, which
does not allow reliable
measurements.
o Distortion is particularly
accentuated in edentulous areas,
where missing teeth and resorption
of the alveolus necessitate film
placement at significant angulation

12. Disadvantages
›Periapical radiographs
are two-dimensional
representations of three-
dimensional objects and
do not provide any
information of the
buccal-lingual dimension
of the alveolar ridge.
Structures that are

13. Disadvantages
› The periapical image is limited by the size of
film being used
› Often, it is not possible to image the entire
height of the remaining alveolar ridge, and
when extensive mesial-distal areas need to
be evaluated, multiple periapical films are
required

14. Digital radiography
› Process wherein the film is replaced by a sensor
that collects the data
› The analog information received is then
interpreted by specialized software and an image
is formulated by a computer monitor

15. › The resultant image can
be modified in terms of
gray scale, brightness,
contrast, inversion and
color enhancement
› Computerised software
programs like
Dexisimplant are
available that allowing for
calibration of magnified
images , ensuring
accurate measurements

16. Advantages
› Less radiation
› Superior resolution
› Instantaneous speed of image
formation is highly useful during
surgical placement of implants and the
prosthetic verification of component
placement
Disadvantage› Size and thickness of the film and position of the
connecting cord sometimes makes film placement difficult
in some sites , such as those adjacent to tori or in case of
tapered arch form in the region of canines

17. Panoramic radiograph
o They display image slices through the jaws by
producing a single image of the maxilla and mandible
and their supporting structures in a frontal plane
o The image receptor is either the radiograph film or
can also be a digital storage phosphor plate or a digital
charge – coupled device receptor

18. Indications:
› Indicated when multiple implant placements
are planned.
› Initial assessment of vertical height of bone
› Evaluation of gross anatomy of the jaws and
any related pathologic findings

19. oThey display anatomic structures like nasal
cavity, maxillary sinus, inferior alveolar canal
and mental foramen.
Advantages:
o Convenience, ease and speed in performance dental office

20. Disadvantages
o The resolution is lesser when compared to intraoral
radiograph.o Cross sectional view is not demonstrated and is of
little use in depicting the spatial relationship between
the structureso A10-20% image magnification occurs, which is non
uniform. This magnification is undesirable for both
implant selection and implant site assessments.
o Geometric distortion and overlapping of images of
teeth can occur.
o Overlapping of anterior region by vertebral
column occurs.

21. Tomography
Tomo= slice ; Graph=picture
o Tomographic units
produce cross-sectional
slices of the jaws that
can be as thin as 1 mm
and are suitable for pre-
and post-implant
assessment
o This technique enables the
visualization of patient’s
anatomy by blurring regions
above and below the section

22. › The basic principle of tomography is that the x-ray tube
and film are connected by a rigid bar called the fulcrum
bar, which pivots on a point called fulcrum.
› When the system is energized, the x-ray tube moves
in one direction with the film plane moving in the
opposite direction and the system pivoting about the
fulcrum
› The fulcrum remains stationary and defines the
section of interest or the tomographic layer

23. › Different patterns of movement, including
linear, circular, spiral or hypocycloidal have
been attempted to reduce blurring artifacts
and provide a sharper and more useful
image.
› Linear tomography is the simplest form ,
which has a one dimensional motion and
produces blurring of adjacent sections and
results in linear steak artifacts in the resulting
image, which may obfuscate the section of

24. ›Circular, spiral and
hypocycloidal are two-
dimensional motions
›Hypocycloidal is
generally accepted as the
most effective blurring
motion
›This technique is difficult

25. tomography
› This technique enables the appreciation of spatial
relationship between the critical structures and the implant
site and quantification of the geometry of the implant site.
The tomographic layers are thick and have
adjacent structures that are blurred and
superimposed on the image, limiting the
usefulness of this technique for individual sites,

26. Advantages
›Cross- sectional
views
›Constant
magnification
Disadvantages:
›Technique-
sensitive
›Blurred images
›High radiation
dose
›Multiple images
needed
›Expensive

27. Computerised Tomography
o CT is a digital imaging technique, which can
generate 3D images using a very narrow “fan beam”
that rotates around the patient, acquiring one thin
slice (image) with each revolution
o It was first applied successfully in
implantology in the 1980s.
The dental CT can be performed with a conventional CT, a
spiral CT or a multislice CT scanner

28. o It allows clinicians to visualize the bony
architecture, nerves, joints, sinuses and other
structures much more completely than traditional flat
radiographs
o CT scans have been shown to be very accurate with
the magnification effect, the same for both the anterior
and posterior area, from a range of 0% to 6% in

29. Advantages
› Negligible magnification
› High contrast image
› 3 dimensional bone models
› Interactive treatment
planning
Disadvantages:
›High dose of
radiation
›Technique –
sensitive
‘FAN BEAM” Geometry

30. Recent advances in CT
Cone Beam Volumetric Tomography
Microtomograph

31. Dentascan
oDentaScan is a computed tomography (CT) software
program that allows the mandible and maxilla to be
imaged in three planes: axial, panoramic and cross-
sectional.
o Data acquisition time for maxilla or mandible is about
15 min.

32. Cone Beam Volumetric
Tomography
› Because of higher radiation exposure, higher cost, huge
footprint and difficulty in accessibility associated with CT, a
new type of CT, CBVT was developed.
NewTom 3G by AFP
MercuRay by Hitachi
3D Accuitomo by J. Morita

33. The images recorded are placed onto
a charge- coupled device chip and is
then converted into axial, sagittal and
coronal slices and permit reformatting
to view traditional radiographic
images as well as 3- dimensional soft
The x- ray tube on these scanners
rotates around 360 degrees and will
capture images of the maxilla and
mandible in 36 seconds , in which
only 5.6 seconds is needed for
exposure
“ Cone beam”
geometry

34. Indications:
CBVT allows precise measurement of distance, area and volume.

35. › Assessment of the positions and states of the
structures critical for adequate implant placement
(e.g., inferior alveolar canal, location of the
neurovascular bundle and the incisive and mental
foramina, pneumatization of the maxillary sinus,
floor of the maxillary sinus, nasal fossa);
Indications:

36. Indications
› Examination after
placement of implants and
bone grafts;
› Evaluation of bone
resorption and root
retention, as well as lesions
of the facial skeleton.

37. › Patients with claustrophobia,
› Parkinson disease
› tremors
› disabling conditions that might cause a
patient to be uncooperative
Contraindications

38. Advantages
o lower cost and more feasible compared to the
computerised tomography
o Radiation dose from a CBVT
scanner is approx. 12.0 mSv ,
which is equivalent to 25 % of
radiation from a typical
panoramic radiograph or to five
D-speed dental x-rays
o Almost 0% magnification
o No
superimposition or
overlapping of
images, hence
minimal distortion

39. Interactive computed tomography
› This technique enables the radiologist to transfer the
imaging study to the practitioner as a computer file and
enables the practitioner to view and interact with the
imaging study on their own computer

40. › It helps to measure the length and the width
of the alveolus, measure bone quality and
change the window and level of the grayscale
of the study to enhance the perception of
critical structures

41.  An important feature of ICT
is that the dentist and
radiologist can perform
electronic surgery (ES) by
selecting and placing arbitrary-
sized cylinders that simulate
root form implants in the
images.
 With an appropriately designed diagnostic
template, ES can be performed to develop
the patient’s treatment plan electronically in
3D

42.  Superimposed on the CBVT
image, electronic implants can be
virtually previewed at arbitrary
positions and orientations with
respect to each other, the alveolus,
critical structures and the
prospective occlusion and
esthetics.
 ES and ICT enable the
development of a 3D treatment
plan that is integrated with the
patient’s anatomy and can be
visualized before surgery.

43. Surgical guides
› Computer generated drilling guides that are
fabricated through the process of stereolithography
using SimPlant software for ideal implant positioning

44. The diameter of the drilling tube is usually 0.2 mm
larger than the corresponding drill, thus making
angle deviation highly unlikely
These successive diameter surgical osteotomy
drill guides may be either bone, teeth or mucosa-
borne
Surgiguides have metal cylindrical tubes that
correspond to the number of desired osteotomy
preparations and specific drill diameters

45. CT based surgical guidance templates and
navigation systems
›These systems allow the transfer of the
pre-surgical plan to the patient , thus
indicating when there is deviation from
the predetermined drilling parameters
›Therefore the depth and trajectory of
drilling sequence is made to the exact
location of the pre-planned position

46. Imaging of vital structures in oral
implantology

47. Mental foramen and mandibular canal
› While using the two-dimensional radiographs for
imaging Mental foramen and mandibular canal ,it is
mainly dependent on the positioning.
› The x-ray beam must be perpendicular to the tangent
of the area in question between the foramen and the
most anterior tooth

48. › If the image is taken from the mesio-oblique
orientation, measurements will be fore-shortened
› If disto-obliquely oriented then measurements
will be elongated
› Always the radiographic density should not
increase above 2.8, after which the foramina
becomes less apparent

49. › In edentulous mandibles,
the risk of error is high
because of the increased
resorption of alveolar
crest
Studies have shown that
the location of mental
foramen on periapical and
panoramic radiograph are
inaccurate and sometimes
on panoramic radiograph
it represents a portion of

50. › Several studies have shown CT to be the most
accurate and highly recommended when
measurements are needed for the inferior
alveolar canal and mental foramen

51. Mandibular lingual concavities
› When there is advanced atrophy
of posterior mandible, lingual
concavities may be present
› Within these concavities
branches of facial artery may be
present
› Over estimation of the amount
of bone may lead to perforation
of lingual plate when drilling with

52. Mandibular ramus
› Donor site for autogenous onlay bone grafting
and is extremely variable in the amount of bone
present . Hence adequate assessment of host
bone present is not possible
› Recommended : CT

53. Mandibular symphysis
› Donor site for autogenous graft
› Panoramic radiographs mostly overestimate the
height of the available bone in the anterior region
› An imaging technique that depicts the true bucco-
lingual amount of bone is recommended
› Recommended: conventional CT

54. Maxillary sinus
› For implant placement detailed information is
needed regarding the position of septa, maxillary
sinus anatomy, sinus pathologies
No radiographic
modality till date
gives more
information on the
above mentioned
features than CT
and hence

55. Intraoperative imaging
› To verify the positioning and location of an osteotomy
site or for identification of a vital structure, processing
of standard radiograph film can take upto 6 minutes
and hence is time- ineffcient
› Current day digital imaging system gives instant
images that can be manipulated, and allows accurate
measurements and maintains aseptic protocol

56. Immediate post operative imaging
› A periapical or panoramic radiograph should be
taken post surgically so that a baseline image can
be used to evaluate against future images
› Additional imaging tools may be used to evaluate
a zone of safety around the vital structures

57. Abutment and prosthetic component
imaging
› When evaluating for transfer of impressions along with
the two- piece implant abutment component placement ,
radiographs should be taken to verify secure adaptation
› Intraoral radiographs are recommended because of their
high geometric resolution to evaluate for any fit
discrepancy
› X-ray beam should be directed at right angle to the
longitudinal axis of the implant. Even a slight angulation
may allow a slight gap to be noticed

58. Post prosthetic imaging
› When investigating complications after implant
placement, a panoramic radiograph is the most
ideal technique
› Whenever Single implant image or a detailed
information of implant viewed on panoramic
image is needed, a periapical radiograph
› A post prosthetic radiograph helps in future
evaluation of component fit verification and also

59. Recall and maintenance imaging
› Follow up or recall radiographs are to be
taken 1 year of functional loading and yearly
for the first 3 years to asses the marginal
bone levels

60. Radiographic sequence for dental implants
imaging
› Pretreatment
› Immediate post surgical (baseline)
› Healing period ( if necessary)
› Second stage surgery
› Post prosthetic surgery ( baseline)
› 1 year postoperatively
› After 1st
year, every 2 years

61. Fabrication of diagnostic templates
› The surfaces of the proposed restorations and the
exact position and orientation of each dental implant
should be incorporated into the diagnostic CT
templates
The design may vary from a vaccuformed reproduction
of the wax-up - to one processed from acrylic
reproduction of the diagnostic wax-up – to a

62. › The processed acrylic template may be modified by
coating the proposed restorations with a thin film of
barium sulfate and filling a hole drilled through the
occlusal surface of the restoration with a gutta-percha
› While radiographic examination GP point will be seen
as radiopaque and will help in determining the position
and orientation of the proposed implant

63. The next design modifies the previous design by drilling a 2 mm hole
through the occlusal surface of the proposed restoration at the ideal
position and orientation of the proposed implant site with a twist drill
The vaccuform templates involve either coating of
the proposed restorations with a thin film of
barium sulfate. This does not depict the ideal
position and orientation of the proposed implant
Another method is to blend 10% barium
sulfate and 90% cold cure acrylic , which
makes the proposed restoration
radiopaque and evident but again does
not give idea about the position and
orientation

64. › Recently radiographic teeth specifically
designed for the fabrication of diagnostic
templates have been introduced .
› These are time saving, placed easily, provide
consistently high radiopacity, have molds
corresponding to prosthetic teeth used in the
final restoration and are bonded easily with
the template-based material

65. Conclusion
› Although many modalities are available for
imaging the implant site, the correct and required
technique should be adopted depending on the
case and the clinician’s judgment to interpret the
image acquired.
› The choice of pre-implant imaging must be
considered carefully due to the radiation dose,
the cost of each examination and the anticipated
information that may be provided by the imaging

66. References
› Misch CE. Contemporary implant dentistry. 3rd ed. St.
Louis: Mosby Elsevier; 2008.Diagnostic imaging and
techniques; p.38-67.
› White SC, Pharoah MJ. Oral Radiology:
Principles and Interpretation. 6th
ed. St. Louis:
Mosby Elsevier; 2009.
› Mi les DA. The future of dental and maxillofacial
imaging. Dent Clin North Am 2008; 52: 917-28.
› Frederiksen NL. Diagnostic imaging in dental
implantology. Oral Surgery Oral Medicine Oral

67. References
› Ganz SD. Presurgical planning with CT-derived fabrication of
surgical guides. J Oral Maxillofac Surg 2005; 63: 59-71.
› Reiskin AB. Implant imaging. DCNA 1998; 42: 47-56.
› Rashedi B, DMD, Tyndall DA. Tuned aperture computed
tomography for cross-sectional implant site assessment in the
posterior mandible. J Prosthodont 2003; 12: 176.
› Vercruyssen M, Jacobs R, Van Assche N, van Steenberghe D.
The use of CT scan based planning for oral rehabilitation by
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68. References
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70. Imaging in oral implantology
Anish Amin