imaging modalities in implants

1. IMAGING MODALITIES IN DENTAL IMPLANTS
-Presented by
Dr Arpita Dutta

2. Contents
INTRODUCTION
HISTORY
CLASSIFCATION OF IMAGING TECHNIQUES
ALARA
EFFECTIVE DOSE
HOW TO INCREASE QUALITY OF R/G
IMAGING MODALITIES
1. Periapical radiography
2. Panoramic radiography
3. Occlusal radiography
4. Cephalometric radiography
5. Tomography
6. Computed tomography
7. CBCT
8. Magnetic resonance imaging
9. Interactive computed tomography
10. Digital Substraction Radiography
FABRICATION OF DIAGNOSTIC TEMPLATES
RADIOGRAPHIC IMAGING OF VITAL STRUCTURES IN ORAL IMPLANTOLOGY
CONCLUSION
REFERENCES

3. “ Successful rehabilitation with implants is highly dependent on accurate imaging as
well as skillful interpretation.
Until the late 1980s conventional radiographic techniques such as intraoral
radiographs, cephalometric and panoramic views were the accepted
standards.
Evolving from there many developments in cross-sectional imaging techniques,
such as spiral tomography and reformatted computerized tomograms
INTRODUCTION
EVOLUTION

4. “
▪ “The surgeons of Vienna and Berlin believe
that the Roentgen photograph is destined to
render inestimable services to surgery. ”
— JAMA, 1896 °
▪ “(Radiation is) the most serious agent of
pollution of the environment and the
greatest threat to man's survival on earth. ”
- E. F. Shumacher, in Small is Beautiful, 1973
TWO SIDES OF THE SAME COIN

5. In 1895 Roentgen discovered X-ray
1896- First intra oral radiograph C. Edmond Kells. New Orleans.
Cephalometrics was introduced in 1922 by Pacini & Carera
1967 Godfrey Hounsfield developed first CT scanner.
1971- CT scanning was introduced into medical scanning.
1972- Walker, Savara &Ricketts made an attempt in the development
of dentofacial imaging in 3-D individually & together with & without
computerization
1990- Tachibana and Matsumoto first reported use of CT in
endodontics.
1997- Quantative Radiology produced the first CBCT, the New Tom
9000, for dental use after the pioneering work of both Arai in Japan and
Mozzo in Italy.
2001 First CBCT licensed for use in USA
Historical Perspective

6. Classification of Imaging modalities
CONVENTIONAL TECHNIQUES-
1. Periapical radiography
2. Digital Radiography
3. Occlusal radiography
4. Cephalometric radiography
5. Panoramic radiography
ADVANCED TECHNIQUES-
1. Tomography
2. Computed tomography
3. CBCT
4. Magnetic resonance imaging
5. Interactive computed tomography.
Can also be
classifed as
ANALOG
DIGITAL
2-DIMENSIONAL
QUASI 3D
3 DIMENSIONAL

7. Planar two dimensional
▪ simple two dimensional projection of the patients anatomy
▪ three dimensional perspective of the patients anatomy with a single image not
possible
▪ With a number of cleverly oriented projections it is possible to develop some
useful three dimensional information
PERIAPICAL BITEWING OCCLUSAL
CEPHALOMETRIC
IMAGING

8. Quasi three dimensional
▪ It includes
▫ X –ray tomography
▫ Cross sectional panoramic imaging techniques.
▪ With these techniques, a number of loosely spaced tomographic images are
produced.
▪ 3-dimensional perspective of the patient anatomy is developed by viewing
each image and mentally filling in the gaps.

9. 3 dimensional imaging
▪ It includes
▫ Computed tomography
▫ CBCT
▫ Magnetic resonance imaging
▪ It enables the clinician to view a volume of the patients anatomy.
▪ These techniques are quantitatively accurate and 3-D models of the patients
anatomy can be derived from the image date and used to produce
stereotactic surgical guides and prosthetic frameworks.

10. Implant imaging can be divided into 3 phases:
Phase1
PRESURGICAL
AND DIAGNOSTIC
IMPLANT IMAGING
PhaseII
SURGICAL AND
INTRAOPERATIVE
IMPLANT IMAGING
PhaseIII
POSTPROSTHETIC
IMPLANT IMAGING

12. Presurgical/pre-prosthetic and diagnostic
Implant Imaging
▪ It involves
a. All past radiologic examinations
b. New radiologic examinations to
assist in final and comprehensive
treatment plan.

13. 1. Identify pathology
2. Determine the bone quantity
3. Determine the bone quality
4. Determine the ideal implant position
5. Determine the ideal implant orientation

14. Effective dose of various imaging modalities
▪ Effective dose-
▪ Panoramic radiograph: 6.3 Sv
▪ Full-mouth intraoral: 150 Sv
▪ Medical CT, both jaws: 2100 Sv
▪ Medical CT, upper jaw: 1400 Sv
▪ *Average natural background radiation
▪ (cosmic radiation, radon, etc.) 3000 Sv per year

15. ALARA – AS LOW AS REASONABLY ACHIEVABLE

16. HOW TO INCREASE IMAGE QUALITY
▪ • Use smallest focal spot possible (a smaller focal spot increases the sharpness of
the image)…this is controlled by the manufacturer
▪ • Increase the distance between the x-ray source and the film
▪ • Place the film as close as possible to the object (e.g. tooth)
▪ • Make the path of the x-rays perpendicular to the film
▪ • Position the film as parallel as possible to the object To reduce radiation
▪ • Stand at least 6 feet away from the unit and/or stand behind a lead shield
▪ • Stand at 90-135 degrees from the path of the x-rays

17. CONTROLLING THE IMAGE QUALITY
• When taking a radiograph, you have control over these three parameters:
1. Kilovoltage
2. Milliamperes
3. Exposure Time
1. Kilovoltage (kVp) - speed at which the electrons move between the cathode and anode of
an x-ray machine.
▪ • Increased kVp, shortens wavelength of xrays and gives them the momentum to travel
through materials better.
▪ • Cause for less contrast in the image (more grey).
▪ • Thus increase kVp is increased only to accomodate a denser object to pass through,
such as a thick mandible.
▪ • kVp range for dentistry is 65-100 kVp.

18. 2. The quantity, or number, of electrons is controlled instead by the temperature
of the filament.
▪ A hotter filament - more electrons. The volume of electrons is measured in
milliamperes (mA).
▪ Affects the intensity of the x-ray.
▪ mA range for dentistry is 7-15 mA.
3.Exposure time refers to how long x-rays are produced or how long the patient
is exposed to them.
▪ • Exposure is often controlled by impulses, with there being 60 impulses in 1
sec.

19. CONVENTIONALTECHNIQUES
Periapical radiography
▪ provide a high resolution planar image
of a limited region
▪ No 2 size dental film provides a 25 by
40 mm view of the jaw with each image.
▪ provide a lateral view of the jaws and no
cross sectional information.

20. ▪ Disadvantages of periapical radiographs
▪ Periapical radiographs suffer from both distortion and magnification.
▪ Grids can be used – but usually provide misleading information.
PARALLELING TECHNIQUE BISECTING ANGLE TECHNIQUE

21. HOW GOOD ARE PERIAPICAL RADIOGRAPHS IN PRE-
PROSTHETIC IMAGING????
▪ It is a useful high –yield modality for ruling out local bone or dental disease.
▪ Is of limited value in determining quantity because the image is magnified,
may be distorted and does not depict the third dimension of bone width.
▪ Of limited value in determining bone density or mineralization (lateral cortical
plates prevent accurate interpretation and cannot differentiate subtle
trabecular bone changes).
▪ Of value in identifying critical structures. But poor in depicting spatial
relationship between the structures and the proposed implant site.
▪ In preprosthetic phase periapical radiographs are often used for single
tooth implants in regions of abundant bone width.

22. Digital radiography
▪ Radiovisiography (rvg) was
invented by Dr Frances Mouyans
▪ The film is replaced by a sensor that
collects the data.
▪ • Data is interpreted by a
specialized software and the image
is formed on a computer screen.
▪ Types of sensors:
• Charge-coupled device (CCD) (commonly used)
• Complementary metal oxide semiconductor /
active pixel sensor (CMOS/APS)
• Charge injection device (CID)

23. ADVANTAGES:
▪ Less radiation because
the sensors are more
sensitive (exposure times
50-90% less).
▪ Immediate result
▪ Ability to enhance the
images
▪ Patient education is better.
DISADVANTAGES:
▪ High cost
▪ Learning curve
▪ Increased thickness of the
sensors & position of the
connecting cord
(Positioning of sensor
difficult in some sites such
as those adjacent to tori or
tapered arch form in region
of canines)

24. Occlusal Radiography
▪ Occlusal radiographs produce
high resolution planar images of
the body of the mandible or the
maxilla.
▪ Placement of film parallel to the
occlusal plane
Central X-ray :--
Mandible: perpendicular to the
film
Maxilla: oblique (usually 45
degrees) to the film.

25. “
Maxillary occlusal radiographs are inherently
oblique and so distorted they are of no quantitative
use for implant dentistry.
Mandibular occlusal radiograph is less distorted
BUT…………
Mandibular alveolus generally flares anteriorly and demonstrates a lingual inclination
posteriorly, producing an oblique and distorted image of the mandibular alveolus
The width at the crest NOT VISUALIZED
Degree of mineralization is not determined
Spatial relationship between critical structures such as mandibular canal and
mental foramen and the proposed implant site is lost.
Occlusal
radiographs
are RARELY
indicated for
diagnostic
preprosthetic
phases in
implant
dentistry

26. Cephalometric radiographs
▪ Oriented planar radiographs of the skull
▪ 10% magnification of the image with a 60 inch focal
object and a 6 inch object to film distance.
▪ Patient’s mid sagittal plane oriented parallel to the
image receptor
▪ With a slight rotation of the Cephalometer, a cross
sectional image of the mandible or maxilla can be
demonstrated in the lateral incisor or in the canine
regions as well.

27. 1. Width of the bone in symphysis region- for ridge
augmentation.
2. Together with regional periapical radiographs
spatial relationships can be visualized.
3. Evaluating loss of vertical dimension
4. Skeletal arch interrelationship
5. Anterior implant crown ratio
6. Anterior tooth position in prosthesis
7. Height and width in anterior region
Uses of the lateral cephalogram
“This technique is
not useful for
demonstrating bone
quality.
Together with regional
periapical radiographs
spatial relationships
can be visualized.”

28. Panoramic radiography/
Orthopantomogram
▪ It is a curved plane tomographic
radiographic technique
▪ Depicts the body of the mandible,
maxilla, and the maxillary sinuses in
a single image.
▪ probably the most utilized
diagnostic modality in implant
dentistry
▪ Not the most diagnostic.
▪ Tomographic section thickness is
approximately 20mm in the
posterior region and 6 mm in
anterior region.

29. ▪ Non uniform magnification of structures
produces images with distortion that cannot
be compensated for in treatment planning
▪ Vertical magnification is approximately 10%.
▪ Horizontal magnification is 20% and varies
according to
▸ anatomic location.
▸ Position of the patient
▸ Focus object distance.
▸ Location of the rotation center
Magnification
in OPG

30. Advantages
Easy identification of
opposing landmarks
Initial assessment of vertical
height of bone
Convenience, ease and speed
Evaluation of gross anatomy
and pathology
Disadvantages
 Distortions
 Does not demonstrate bone
quality.
 Is misleading quantitatively
because of magnification and no
third dimension
 of little use in depicting the
spatial relationship between the
structures and dimensional
quantification of the implant site.
 Dimensions of inclined structures
cannot be relied upon in
panoramic radiographs.

31. ▪ Posterior maxillary regions are generally the least distorted regions of the
panoramic radiographs.
▪ Maxillary edentulous anterior region is often the most difficult area of a
panoramic radiograph to evaluate because of the curvature of the alveolus
and the inclination of the bone.

32. Zonography/ Narrow Angle Tomography
▪ This is a modification of the panoramic x-ray machine with
the capability of making a cross sectional image of the jaws.
▪ Tomographic angle is small- 10degrees
▪ 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.
▪ Has a thick zone of focus 25mm
▪ Useful when subject contrast is low therefore less
difference in physical density of adjacent structures- eg
Lung imaging

33. Conventional Tomography
▪ It is a generic term, formed from the reek words tome(slice ) and
graph(picture).
▪ It was adopted in 1962 by the international commission on radiologic
units and measurements(ICRU) to describe all forms of body section
radiography.

34. PRINCIPLE
▪ X- ray unit and the film are connected by a rigid bar
called the fulcrum bar, which pivots on a point called the
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.
▪ Structures that are in the plane (focal area) of rotation
are depicted in sharp focus, while structures outside the
plane of rotation are blurred
▪ The resulting image is a true cross section of the
structures within the imaged plane, which is
perpendicular to the x-ray beam

35. Indications- • Single-site evaluation
• Vital structures evaluation
▪ Advantages-
▪ • Cross-sectional views
▪ • Constant Magnification
▪ Limitations
▪ • Availability
▪ • Cost
▪ • Multiple Images •
▪ Technique sensitive •
▪ Images
▪ • High radiation dose

36. ▪ Linear tomography
▪ is the simplest form of tomography where the X-ray tube and film move in a straight
line.
▪ Complex motion, high quality tomography is described by two dimensional motion of the
tube and film.
▫ It results in relatively uniform blurring of the regions of the patients anatomy
adjacent to the tomographic section.
▫ Hypocycloidal motion is generally accepted as the most effective blurring motion.

37. Computed tomography
▪ Computed tomography(CT) is a
digital and mathematical
imaging technique that creates
tomographic sections where the
tomographic layer is not
contaminated by blurred
structures from adjacent
anatomy.

38. ▪ It enables differentiation and
quantification of both soft and hard
tissue.
▪ CT was invented by sir Hounsfield
and announced to the imaging world
in1972.
▪ Ct produces axial images of a patients
anatomy .
▪ Axial images are produced
perpendicular to the long axis of the
body.

39. ▪ The X-ray source is attached rigidly to a
fan-beam geometry detector array, which
rotates 360 degrees around the patient and
collects data.
▪ The image detector is either a gaseous or
solid state producing electronic signals that
serve as input data for a dedicated
computer.
▪ The computer processes the data
▪ The individual element of the CT image is
called a voxel, which has a value, referred to
in hounsfield units, that describe the
density of the CT image at that point

40. FOCAL SPOT
▪ The focal spot is the area of the x-ray tube that emits the x-rays.
▪ smaller the focal spot, the sharper the final image quality.
▪ a larger source or focal spot will result in projections of shadows of
the scanned area, which will result in blurring of the object.
▪ This penumbra or blurring of the edges creates a shadow with
resultant poor image quality and clarity.
▪ Current CBCT units have focal spots ranging from 0.15 to 0.7 mm

41. FIELD OF VIEW
The field of view of cone-beam computed
tomography units: small (A), mid (B), and large
(C).
•Cone-beam computed
tomography units vary on
the area of interest or what
is commonly termed the
field of view in radiology.
•The FOV describes the
scan volume, which is
dependent on detector size
and shape, beam projection
geometry, and beam
collimation
•CBCT units are classified
as small, mid, or large
FOVs

42. ▪ Ct scanners are standardized at a hounsfield value of 0 for water.
▪ The CT density scale is quantitative and meaningful in identifying and differentiating
structures and tissues.
▪ The original imaging computer can create secondary images from almost any
perspective by reprojecting or reformatting the original three dimensional voxel data.
▪ The utility of CT for dental implant treatment planning was obvious from the beginning
▪ But the access to these imaging techniques was limited.
▪ This led to development of specific techniques generally referred to as Dentascan
imaging.

43. Tissue Hounsfield
units
Air -1000
Water 0
Muscle 35-70
Fibrous tissue 60-90
Cartilage 80-130
Trabecular
bone
150-900
Corticalbone 900-1800
Dentine 1600-2400
Enamel. 2500-3000
Density Hounsfield
units
D1 >1250
D2 850-1250
D3 350-850
D4 150-350
D5 <150

44. Dentascan
▪ The radiologist simply indicates the
curvature of the mandibular or maxillary
arch.
▪ the computer is programmed to generate
referenced cross sectional and
tangential/panoramic images of the
alveolus along with 3-D images of the
arch.
▪ The cross sectional and panoramic images
are spaced 1mm apart and enable
accurate preprosthetic treatment
planning.

45. ▪ Types of CT Scanners–
▪ These CT scanning units are tomographic machines that are classified as
4-, 8-, 12-, 16-, 32-, and 64-slice machines.
▪ The number of slices corresponds to the number of times the x-ray beam rotates
around the patient’s head
▪ CT spiral slices produce “average” reconstructed images based on multiple x-rays
transversing the scanning area.
▪ With this reconstruction of images, a small gap between each slice is present, which
contributes to an inherent error within medical scanners.

46. DISADVANTAGES:
▪ Because medical scanners were not developed for dental reformatting, there existed
inherent errors such as distortion, magnification, and positioning problems that led to
inaccuracies when reformatted.
▪ Radiation exposure of medical scans has been shown as excessive (equivalent to 20
panoramic radiographs.)
▪ No prosthetic information could be gathered to predict the final prosthetic outcome
▪ This was overcome with the advent of sophisticated scanning appliances,
stereolithographic resin bone models, interactive software, computer generated
surgical guides, and CT-based image-guided navigation systems
Comparison between radiation
dosage of OPG, CT and CBCT
OPG- 6.3Sv
CT- 2100Sv
CT20times OPG
Cbct3-6times OPG

47. ▪ CT enables
▫ Identification of disease
▫ Determination of bone quality
▫ Identification of critical structures
▫ Determines orientation and position of implants
▪ Thus CT is capable of determining all of the radiologic objectives of the
pre-prosthetic implant imaging.
▪ Usually a diagnostic template is necessary to take full advantage of the
technique.

48. CONE BEAM VOLUMERIC TOMOGRAPHY or CONE BEAM
COMPUTED TOMOGRAPHY
▪ • To overcome some of the disadvantages of conventional medical CT
scanners
▪ • The x-ray tube captures images of the maxilla and mandible in 36
seconds, in which only 5.6 seconds is needed for exposure.
▪ The images recorded are placed onto a charge coupled device chip are
then converted into axial, sagittal, and coronal slices, and permit
reformatting to view traditional radiographic images as well as three-
dimensional soft tissue or osseous images

49. CT vs CBVT
▪ Medical versus Cone Beam Technology Radiation Dosages.
▪ CBVT scanner -12.0 mSv (micro sieverts). Medical scanners -40 to 60 times
that of CBVT doses
▪ Image Acquisition of Medical versus Cone Beam Scanners. Medical CT scans
produce images of transaxial planes. However, between each parallel slice
exists a small “gap” that contributes to a built-in error within medical
scanners. CBVT accumulates data from one 360-degree rotation and are void
of any “gaps,” thus eliminating distortion and magnification.

50. ▪ Shape of radiation beams
▪ In contrast to the fan-beam
generated by CT scanners, the
CBCT scanner generates a
cone-shaped x-ray beam,
which images a larger area.
▪ Thus, at the end of a single
complete rotation, 180 to 500
images are generated
▪ The computer uses these
images to generate a digital,
three-dimensional map of the
patient’s anatomy

52. INTERACTIVE COMPUTED TOMOGRAPHY(ICT)
▪ It address many of the limitations of CT.
▪ ICT is a technique that was developed to bridge the gap in information
transfer between the radiologist and the clinician.
▪ The radiologist transfers the imaging study to the clinician as a computer file
for clinician to view and interact with the image in their own computer.

53. ▪ Clinicians computer becomes a diagnostic radiologic workstation with tools to
measure the length and width of the alveolus measure bone quality ,and
change the window and level of gray scale of the study to enhance the
perception of critical structures.
▪ An important feature of the ICT is that the clinician and radiologist can perform
“electronic surgery “ (ES) by selecting and placing arbitrary size cylinders that
simulate root form implants in the images.

54. Limitations of ICT.
▪ Refinement and exact orientation of the implant positions is difficult and
cumbersome.
▪ Executing the plan maybe difficult for the surgical team.

55. SIMPLANT
▪ INDICATIONS:
▪ use as a software interface and image segmentation system for the transfer of imaging information from a medical
scanner such as a CT scanner.
▪ It is also intended as pre-planning software for dental implant placement and surgical treatment.
▪ SIMPLANT 17 software functionality includes:
 • Reading and 3D reconstruction of (CB) CT slice images (*)
 • Implant planning
 • 3D transparency tool for investigation of the position of the nerve and the implants
 • Assessment of bone density
 SIMPLANT Guide for precise transfer of the implant plan to the patient’s mouth

56. HOW DOES THE SOFTWARE WORK?
It is not rocket science!!!!!
•The SIMPLANT software
simply enables the
operator to visualise the
axial cross-sections of the
proposed implant site.
•The virtual implants can
be positioned.
•And a stereolithographic
guide can be fabricated to
aid in the implant surgery

57. Magnetic resonance imaging.
▪ MR is a imaging technique used to image the
protons of the body by employing magnetic
fields, radio frequencies,electro magnetic
detectors,and computers.
▪ The technique was first announced by
Lauterbur in 1972.
▪ It is a 3 dimensional imaging technique with an
electronic image acquisition process and a
resulting digital image.

58. ▪ The body is made of billions of atoms
▪ The nuclei spins on an axis, a bit like a spinning top
▪ The atom that the MRI uses is the hydrogen atom
▪ It has a single proton and is the most strongly affected by the Magnetic field – it is more likely to
line up than other atoms
▪ Inside the magnetic field the protons are lined up and ready to go.
MRI vs CT-
Complex tomography fails to differentiate the inferior alveolar canal in 60% of the implant
cases CT fails to differentiate the inferior alveolar canal in approximately 2% of implant
cases.MRI visualizes and differentiates the inferior alveolar canal and neurovascular
bundle from the adjacent trabecular bone.MR

59. ▪ MR is used in implant imaging as a secondary imaging technique when
primary imaging techniques such as complex tomography,CT or ICT fail.
HOWEVER………..
▪ MR is not useful in characterizing bone mineralization or a high yield
technique for identifying bone of dental disease.

60. SURGICAL AND INTERVENTIONAL IMPLANT IMAGING
▪ It assists in the surgical and prosthetic intervention of the patient.
▪ Objectives
1) Evaluate the surgery sites during and immediately after surgery.
2) Assist in the optimal position and orientation of the dental
implants
3) Evaluate the healing and integration phase of implant surgery.
4) Ensure abutment position and prosthesis fabrication are correct.

61. ▪ As most implant surgeries are performed in the doctors office rather than
in hospital ,the modalities are usually limited to periapical and panoramic
radiography.
▪ The patient can be generally imaged at chair side with periapical
radiography to determine implant/osteotomy depth,position and
orientation.
▪ Disadv : dark room procedure.

62. Postprosthetic implant imaging.
▪ It commences just after the prosthesis placement and continues as long
as the implants remain in the jaws.
▪ Objectives
1. Evaluate the long term maintenance of implant rigid fixation
and function.
2. Evaluate crestal bone levels
3. Evaluate the implant complex

63. Bite wing radiographs
▪ The short and long term evaluation of
crestal bone loss around implants is
best evaluated with Intraoral
radiographs.
▪ In these images ,the superior one third
of the implant is the region of interest.
▪ Threaded implants make
quantification of marginal bone loss
easier to read.

64. Temporal digital subtraction radiography(DSR).
▪ It is a radiographic technique that enables two
radiographs made at different points of time of
the same anatomic region to be subtracted
resulting in an image of the difference between
the two original radiographs.
▪ shows changes in patients anatomy,such as
alveolar mineralization or volume changes.
▪ more accurate at depicting changes in bone
mineralization and bone volume
▪ SR has limited utilization in clinical practice
because of the difficulty in obtaining reproducible
periapical radiographs.

65. RADIOGRAPHIC IMAGING OF VITAL STRUCTURES
IN ORAL IMPLANTOLOGY
Mandibular Lingual Concavities
▪ Advanced atrophy in the posterior mandible is
present, lingual concavities may be present.
▪ branches of the facial artery may be present.
▪ Overestimation of the amount of bone may lead to
perforation of the lingual plate.
▪ Lingual bleeding problems - even be life-
threatening.
▪ Assessment of the posterior mandible - cross-
sectional tomography is recommended.

66. Mandibular Ramus (Donor Site for Autogenous
Grafting)
▪ The mandibular ramus area has become a very
popular donor site for autogenous onlay bone
grafting.
▪ This area of the mandibular jaw is extremely
variable in the amount of bone present.
▪ Usually panoramic images are taken and the
location of the external oblique and the
mandibular canal is noted.
▪ For accurate representation - use of computerized
tomography.
▪ The more prominent the external oblique ridge,
the better candidate for the ramus as a donor
site

67. Mandibular Symphysis
.
▪ A common position for implants in
mandibular edentulous patients and used
as a donor site for autogenous grafting.
▪ When two-dimensional images are used,
inherent errors may occur because of
lingual concavities.
▪ Radiographs including lateral cephalometric
and conventional CT, may be used.

68. Maxillary Sinus
▪ CT, which is the gold standard for viewing
the osseous structures and evaluating
pathology in the sinuses.
▪ It provides detailed information regarding
–
 Prevalence and position of septa
 Maxillary sinus anatomy
 Detection of sinus pathology
The left maxillary sinus has thickened mucosa and
is a contraindication for a sinus graft
without resolution of the sinus pathology.

69. FABRICATION OF DIAGNOSTIC TEMPLATES
▪ • The purpose of diagnostic radiographic
templates is to incorporate the patient’s
proposed treatment plan into the radiographic
examination.
▪ • The preprosthetic imaging procedure enables
evaluation of the proposed implant site at the
ideal position and orientation identified by
radiographic markers incorporated into the
template.

70. FIGURE 7-26. A, Without a radiopaque template, the correct angulation for placement cannot be
determined. B, With a radiopaque template made from diagnostic casts. C and D, The reformatted images
show the exact location for ideal placement.

71. ▪ Computed Tomography
▪ The precision of CT enables use of a
complex and precise diagnostic
template.
▪ the exact position and orientation of
the implant, which many times
determine the actual length and
diameter of the implant, often are
dictated by the prosthesis.
▪ As such, a diagnostic template used
during imaging is most beneficial.

72. CT templates
▪ The surfaces of the proposed restorations and the exact position and
orientation of each dental implant should be incorporated into the diagnostic
CT template.
▪ Designs for diagnostic CT templates have evolved:-
simple vacuform
reproduction of the
wax-up
one produced from a
processed acrylic
reproduction of the
diagnostic wax-up
sophisticated types
fabricated with
specifically designed
radiopaque denture
teeth.

73. ▪ • 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 gutta- percha.
▪ • The surfaces of the proposed restoration then become radiopaque in the CT
examination, and the position and orientation of the proposed implant may be
identified by the radiopaque plug of gutta-percha within the proposed
restoration.

74. ▪ • Radiopaque teeth designed for the fabrication of diagnostic templates for
fixed and removable implant-supported restorations have been introduced.
▪ Advantages –
• The diagnostic template then can be modified into a surgical template
• They are time saving
• Easily placed • Provide high radiopacity
• Bond easily with the template.

75. Zahran MH, Fenton A. A radiopaque implant template for partially edentulous patients.
Journal of Prosthetic Dentistry. 2010 Jun 1;103(6):390-2.
1 Diagnostic arrangement in
edentulous area.
2 Clear vacuum-formed matrix
(template) adapted on diagnostic cast
3 Putty material filling edentulous
area.
4 Pilot holes drilled through
template and putty material
5 Cross-sectional axial CBCT image showing maxillary
alveolar ridge and template.

76. Immediate Loaded Prosthesis- The immediate smile
technique
▪ The newest technological
advancement in CT-guided surgery
▪ After the virtual treatment plan is
created by the implant team,
computer-generated
stereolithographic surgical guides are
fabricated
▪ The lab uses the fabricated surgical
guides and mounted study casts to
fabricate interim or final prostheses
to be inserted immediately after
implant placement.

77. Radiographic signs associated with failing endosseous
implants
▪ Radiographic appearance Clinical implications
▪ Thin radiolucent area that closely follows the entire outline Failure of implant to integrate with adjoining bone.
▪ Radiolucent area around coronal portion Peri-implantitis resulting from poor plaque control,
adverse loading or both
▪ Apical migration of alveolar bone one side of implant Non axial loading resulting from improper angulation
of implant
▪ Widening of periodontal space of the nearest natural abutment Poor stress distribution
▪ Fracture of fixature Unfavorable stress distribution during function

78. ▪ 1. Division A: available bone with no approximate vital structures
o Panoramic radiograph
o Supplemental periapical radiographs if needed
▪ 2. Division A: available bone with approximate vital structures
▪ 3. Division B: available bone
▪ 4. Division C: available bone
▪ 5. Division D: available bone (allografts, autographs, sinus grafts)
o Panoramic radiograph
o Conventional or computed tomography
o Supplemental periapical radiographs
▪ 6. Division A, B, C, D: available bone in which computed tomography
does not clearly distinguish exact location of mandibular canal or mental
foramen
▪ 7. Infection (osteomyelitis)
o Magnetic resonance imaging
AVAILABLE BONE:
Describes the external
architecture or the quantity of
bone present in edentulous area
considered for implants
DIVISION A BONE- Consists of
abundant bone in all directions
DIVISION B BONE- Barely sufficient
bone. Ridge width is reduced.
DIVISION C(COMPROMISED
BONE)- Deficient in one or more
dimensions. Resorption first
occurs in width .The bone is
called C-w Then in height. The
bone is called C-h
DIVISION D (DEFICIENT BONE) -
Characterized by severe atrophy
of alveolar process as well as
basal bone
Recommended Imaging for Implant Treatment Planning

79. • Many radiographic projections are available
for the evaluation of implant placement, each
with advantages and disadvantages
The clinician must follow sequential steps in
patient evaluation, and radiography is an
essential diagnostic tool for implant design
and successful treatment of the implant
patient
CONCLUSION
“The distance between what you want
and what you get is what you do.”

80. REFERENCES
1. • Contemporary Implant Dentistry. Carl E.
Misch – 3rd Edition
2. • Caranza's Clinical Periodontology - 11th
Edition
3. • Swati S Bhosale, P Balaji Raman and Joshua
Mall. Guided implant placement in the
edentulous mandible: A novel approach.
Journal of ICDRO 2010; Vol 2 (1): Page 30 –
34.
4. • Lingeshwar D, Dhanasekar B, Aparna IN.
Diagnostic Imaging in Implant Dentistry.
International Journal of Oral Implantology and
Clinical Research, September-December
2010;1(3):147-153
5. • Bart Vandenberghe Reinhilde Jacobs Hilde
Bosmans, Modern dental imaging: A review of
the current technology and clinical applications
in dental practice. Eur Radiol 2010 20: 2637-
2655

81. Thank You