2. dr.ESLAM MOSAAD
X-ray
X-rays were first discovered in
1895 by Wilhelm Conrad Roentgen,
the professor of physics and
director of the physics institute at
the University of Wurzburg in
Bavaria.
Hence the term ROENTGEN
RAYS, often applied to mechanically
generated x-rays. He won a Noble
prize for his discovery of X-ray.
Roentgen called them X-rays
after the mathematical symbol X
for unknown.
History History History
3. dr.ESLAM MOSAAD
History History
History
Roentgen soon found that photographic
plates were sensitive to the newly discovered
rays.
He convinced his wife to participate in an
experiment.
Roentgen placed her hand on a cassette
loaded with a photographic plate. He then
aimed the activated cathode ray tube at her
hand for fifteen minutes.
When the image was developed, the bones
of her hand and the two rings she wore were
clearly visible.
X-ray of Bertha Roentgen's Hand
6. dr.ESLAM MOSAAD
Panoramic radiography
rotational radiography, or curved surface tomography
It is a radiographic technique for
producing a single image of the facial
structures that includes both maxillary and
mandibular arches and their supporting
structures.
8. dr.ESLAM MOSAAD
As Tomographic principles, the x-ray
tube and film cassette rotate in opposite
directions around the patient’s head to
produce a specific curved image of the
maxilla and mandible on the film.
10. dr.ESLAM MOSAAD
• In panoramic technique, during exposure,
the x-ray source moves in one direction
while the film moves in the opposite
direction
• The area of the object in the center of this
movement will appears in focus and very
sharp on the resultant radiograph as its
shadow.
• All other structures will appears blurred or
out of focus
13. Diagnostic imaging and techniques, help develop and
implement a cohesive and comprehensive treatment plan to the
implant patient.
Diagnostic Imaging objectives depend on a number of factors
including :
• The amount and type of information required
• The time period of the treatment rendered.
dr.ESLAM MOSAAD
14. Imaging modalities
• Depend on the patient clinical needs.
• The imaging modality should yield the necessary diagnostic
information versus the least radiologic risk.
• Examinations that are known to produce this result are not
necessarily those that cost the least.
• Basically the dentist should use the modality that provides the
standard of proper care .
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15. Imaging modalities can be described as
1-Analogue
-2 dimensional systems
-use x-ray films or intensifying
screens
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16. 2-Digital
• Two dimensions : described by an image matrix that has an
individual picture elements called (pixels)(width X height)
• Three dimensions: described by an image matrix that has an
individual picture elements called(voxels) (width X height X
depththickness)
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17. The decision of when to image along with which
modality to use depends on the integration of the
previous factors and can be organized into three
phases:
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19. Global objectives
• Develop and implement a treatment plan for
the patient that enables restoration of the
patient’s function and esthetics.
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20. Specific Objectives:
• identify disease.
• determine bone quality.
• determine bone quantity.
• Determine implant position.
• Determine implant orientation.
dr.ESLAM MOSAAD
23. 1-periapical radiographs
These are images of a limited region of the mandibular and
maxillary alveolus.
• Common technique used: long cone paralleling technique,to
eliminate and to limit the magnification distortion to less than
10%.
• Film used :commonly among our clinics is no.2 size dental film
which provides (25-mm X 40-mm)view of the jaws.
dr.ESLAM MOSAAD
24. In terms of objectives of
preprosthetic imaging
• Useful high –yield modality for ruling out local bone and dental
disease.
• Of value in identifying critical structures but of little use in
depicting the relationship between the proposed implant site
and those structures.
• Limited value in determining quantity because the image is
magnified and does not depict the third dimension of bone
width.
dr.ESLAM MOSAAD
25. • Limited value bone density or mineralization(the lateral
cortical plates prevents accurate interpretation and
cannot differentiate the subtrabecular bone changes.
These films most often are used for single-
tooth implants in region of abundant bone
width.
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26. 2-Occlusal radiographs
Common technique used :placing the film
intraorally parallel to the occlusal plane with
the central X-ray beam
1)oblique usually 45degrees for the maxillary
images ,this is why the images are inherently
distorted.
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27. 2) perpendicular to the film for the mandibular image ,which is
usually less distorted than the maxillary image ,but the
mandibular alveolus generally flares anteriorly and
demonstrates lingual inclination in the posterior region,
producing an oblique and a distorted image .
• As a result occlusal radiographs rarely are indicated for
preprosthetic phases in implant patient.
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28. 3-cephalometric radiographs.
• These films usually provide useful information for the 1-cortical
thickness , 2-height and 3-width of the alveolar ridge at the mid
line ,as well as the 4-skeletal relationship between the maxilla
and the mandible and 5-facial profile.
• Their use in implant patient is limited to structures at the mid
line , with minimal usefulness for other areas of the jaws.
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30. 4-panoramic radiography.
Curved plane tomographic radiographic
technique used to depict the body of the
mandible , maxilla and the lower half of the
maxillary sinuses in a single images.
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31. Advantages of panoramic radiographs
• Opposing land marks are easily identified .
• The vertical height of bone initially can be assessed.
• Convenient ,easy and speed procedure that can be
carried in most dental offices.
• Gross anatomy of the jaws and related pathologic
findings can be evaluated.
• Popular and widely available technique in dentistry.
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32. disadvantages
• Does not demonstrate bone quality minerlaization.
• Misleading because of magnification and third
dimensional cross sectional view is abscent.
• Does not depict the spatial relation between the
structures and dimensional quantitation of the implant
site.
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34. • Diagnostic templates that have 5-mm ball bearings or
wires are incorporated around the curvatureof the dental
arch and worn by the patient ,to enable the dentist to
evaluate the magnification in the radiograph.
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35. • Recently a modification of the panoramic x-ray machine
developed that has the ability of making cross sectional image
of the jaws.
• These devices use limited angle linear tomography
(zonography) and means of positioning the patient.
• Tomographic layer of 5mm.
• This technique enables correlation between spatial structures
and implant sites and quantification of the geometry of the
implant site.
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36. 5-Tomgraphy
• This is a generic term formed from greek words tomo
(slice) and graphy (picture).
• It describes all forms of body sectoin radiography.
• It is a special X-ray technique that enables visualization
of a section of the patient anatomy by blurring regions
of the patient’s anatomy.
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37. • In conventional tomography the X-ray source and the
film are connected and rotate around a fixed
point(fulcrum)usually performing simple ( linear )or
complex (elliptic or hypocycloidal)tomographic
motions.
• Structures that are in the plane (focal area)of
rotation do not move in realtion to the tube and the
film and thus are depicted in the sharp focus .
• Structures outside the plane of rotation are blurred
progrssively depending on their distance from the
focal plane.
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38. Advantages :with proper patient seating
• Generates a true cross section of the alveolar ridge.
• Provide diagnostic information of the cortical
thikness , trabecular density , height and width of
the alveolus and location of vital anatomic
structures.
• Imaged structures are predictably magnified , so
measurments made of tomograms can be adjusted
to provide accurate angular and linear assesments.
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39. • Dose is limited as the area of the jaw imaged
is limited
• Useful during the placement of a single or
few implants.
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40. Disadvantages
• Equipment requires familiarity with the image
acquissaton.
• Image interpretation is some times
challenging . especially when the anatomy of
the jaws are altered because of traumatic
extractions , alveolar ridge resorption , and
other conditions.
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41. • The progressive blurring of structures outside the focal
plane does not allow sharply defined tomographic slices ,
the prominent opaque structures can cast ( ghost )
shadows and complicate the images.
• Generated images are created once a time ,so patient
has to be repositioned each time
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42. 6-Computed tomography(CT)
• CT was invented by sir Hounsfield in1972.
• CT enabled differentiation and quantification of
soft and hard tissues.
• The individual element of the CT is called a voxel ,
which has a value referred to in Hounsfield
units,that describes the denisty of the CT image
at each point .
• Each voxel contains 12bits of data and ranges
from -1000 (air) to +3000 (enamel /dental
materials)and 0 for water.
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43. • A thin fan-beam of X-rays rotates around the patient to
generate in one revolution a thin(0.5-1.00mm wide)axial slice
of the area of interest.
• Multiple overlapping axial slices are obtained by several
revolutions of the X-ray beam until the whole area of interest is
covered.
• The image detector is Gaseous or solid state ,producing
electronic signals that serve as input data for a dedicated
computer .
• The computer processes the data using back –projection fourier
algorithm techniques.
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47. • A three dimensional digital map of the jaws are constructed,and
a specialized software can be used to generate approprite
views that can depict the dimensions of the jaws and the
location of the important anatomic structures.
• Typical dental views obtained from a CT scan include axial
,panoramic,and cross- sectionalviews of the jaws.
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50. Advantages
• True cross sections offer a precise and detailed evaluation of
the height and width of the alveolar ridge.
• The images can be adjusted and printed without magnification.
, facilitating measurments directly from the prints or films . with
standard rulers not magnified.
• Anatomic structures can be visualized and analyzed at all three
coordinate axes.
• Bone and soft tissue contrast and resolution are excellent for
the diagnostic task.
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51. Disadvantages
• requires specialized equipment.(expensive)
• High radiation dose compared to other modalities.
• Metallic restorations cause ring artifacts.
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52. Dentascan imaging
• Provides programmed reformation , organization , and
display of the imaging study.
• The radiologist determines the curvatures of the
maxillary or the mandibular arch and the computer is
programmed to determine referenced cross sectional and
tangentialpanoramic images of the alveolus along with
three dimensional images of the arch.
• The cross sectional and panoramic images are spaced
1mm apart and enable accurate pre prosthetic treatment
planning.
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53. Denta scan images of
reformated and
reorganized CT images
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54. Limitations
• May Not be true in size ,and require compensation for
magnification .usually a diagnostic template is required
to take full advantage of the technique.
• The diagnostic template usually contains lead balls of
known diameter ,to calculate the magnification.
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55. 7-Cone beam computed
tomography
• CBCT scanners generates a cone shaped X-ray beam in contrast to the
fan shaped beam produced by CT scanners.
• Images are generated in 1- degree increments, at the end of a single
rotation 360 images are created.
• Computer then uses these images to create a 3-D map of the face.
• Multiplanar reconstructions of sections of variable thickness can be
reconstructed as the CT scan.
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56. • CBCT offers the same advantages and disadvantages of
CT, with only few differences.
The most important difference is that
• CBCT delivers a radiation dose which is similar to full
mouth x-ray, this is 50-100 times less the radiation dose
deliverefor CT.d
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57. Interactive computed tomography
• A technique that was developed to bridge the gap
in information transfer between the radiologist and
the practitioner.
• Dentist’s computer becomes a radiologic workstation
with tools 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 the critical structures.
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58. • Electronic surgery(ES) can be performed by the dentist
and the radiologist .
• By selecting arbitrary –size cylinders that simulates root
form implants in the images .
• With appropriate diagnostic template ,ES can be
performed to develop the patient’s treatment plan
electronically in three dimensions.
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60. Advantages
• Three dimensional treatment plan that is integrated with
the patient’s anatomy and can be visualized before
surgery.
• Enables the determination of bone quality adjacent to
the prospective implant sites.
Limitations
• Refinement and exact orientation (parallelism of the
electronic implants is difficult
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61. 8-Magnetic resonance imaging
Technique :
• Imaging protons of the body using magnetic
field ,radio frequancies,and electromagnetic
detectors and computers .
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64. Usage :
• When complex tomography fails to differentiate inferior
alveolar canal in about 60 % of cases and CT fails to
differentiate the inferior alveolar canal in about 2% of
the cases.
• MRI visualizes the fat in the trabecular bone and
differentiates the inferior alveolar canaland neuro
vascular bundle from adjacent trabecualr bone.
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65. Limitations
• Not useful in characterizing bone
mineralization or as a high-yield technique for
identifying bone or dental disease.
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66. Diagnostic templates
• Purpose :is to incorporate the patient proposed
treatment plan into the radiographic examination
• The pre prosthetic imaging procedure enables
evaluationof the proposed implant site at the ideal
position and orientation identified by radiographic
markers incorporated into the template.
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67. Several types for diagnostic templates to
be effective and more precise
1-clear acryl and radio opaque denture teeth.
2-acryl and the restoration sites is covered by barium
sulfate and filling a hole drilled through the occlusal
plane with guttta percha..
• N.B : do not use metal markers if CT or CBCT is going to
be carried.
dr.ESLAM MOSAAD
70. CAD-CAM STEREOTACTIC SURGICAL
TEMPLATES
• Depends on producing a three dimensional model of
the patient’s alveolar anatomy using a computer
aided manufacturing (CAD-CAM) and rapid proto
typing procedure.
• Derived from the model by aligning cylinders at the
implant sites which just accommodate pilot drill.
• Used to establish pilot drilling up to 10mm then the
template is removed and the osteotomies
Are completed.
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71. Phase two
surgical and interventional implant
imaging
• Involves imaging the patient during and
immediately after surgery.
Purpose:
• Evaluation of depth of implant placement.
• Position and orientation implant osteotomies.
• Evaluation of graft sites.
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72. • This is usually carried at the dentist’s office this is why it
is usually the periapical and the panoramic
radiography.
• Digital radiography software facilitated the process.
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73. Advantages of digital radiography for
the implant surgery.
• Fast
• Low radiation.
• Calibration.
• Magnification.
• Excellent quality.
• Measures depth,density, and neighbouring
structures.
• Patient stays in surgical setting
• Keeps aseptic setting
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74. Phase three
post prosthetic implant imaging
Purpose:
• Evaluate status and prognosis of the dental implants.
• Evaluate bone adjacent to the implant for changes in
mineralization or bone volume.
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76. Bite-wing radiographs
Purpose :
• Evaluate crestal bone loss around the implants.
• In this image the superior third of the implant is the
region of interest.
• A vertical bitewing film is ideal once prosthesis is in
place.
• Quality periapical and bitewing radiographs should be
parallel to the implant body with the central ray of
source oriented perpendicular to the film enable
sequential radiographs for crestal and periimplant bone
loss.
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77. Temporal subtraction radiography:
• (SR) is a radiographic technique that enables two
radiographs made at different points of time and
of the same anatomical region to be subtracted
resulting in an image of the difference of the two
original radiographs.
• Needs to be standardized to account for changes
in exposure and processing between each
radiograph then they can be digitalized registered
and subtracted with a resulting subtraction
image.
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78. a. Immediately after tooth extraction
b. At 12 months after tooth
extraction
Blue region = ROC, Red region = ROI
Blue figures 1-6 = reference points
a. Immediately after tooth extraction b. At 12
months after tooth extraction
Blue region = ROC, Red region = ROI
Blue figures 1-6 = reference points
c. Resulting subtraction image
d. Resulting subtraction image
Blue area in ROI = Bone gain
Red area in ROI = Bone loss
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79. Advantages:
• More accurate than periapical in depicting the changes
in bone mineralization and bone volume.
Limitations :
• Difficulty to obtain a reproducible radiograph.
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80. Computed tomography
• Unlike the conventional imaging techniques the
resolution ,, spatial discrimination ,and three
dimensional imaging capabilities of CT enable
• precise evaluation of the position of the dental
implant relative to critical structures .
• failing implants characterized by trabecular and
crestal demineralization,resorption ofbone
implant interface,cortical plate fenestrations and
perforation of the inferior alveolar canal.
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81. conclusion
• Many radiographic projections are available for the
evaluation of implant placment. each with advantages and
disadvantages . the clinician must follow sequential steps
inpatient evaluation, and radiography is an essential
diagnostic tool for implant patient . selection of appropriate
radiographic modalities will provide the maximum diagnostic
information , help avoid unwanted complications and
maximizes treatment outcome while delivering as low as
reasonably achievable(ALARA) radiation dose to the patient.
dr.ESLAM MOSAAD
