in prosthodontics

1. Presented by:-
Dr. Richa Sahai
II MDS
Guided by:
Dr. U.M. Radke Dr. N.A. Pande Dr. S Deshmukh
HOD & Guide Professor Reader
Dr. T.K. Mowade Dr. R. Banerjee Dr. A. Chandak
Reader Reader Reader
Radiographic Considerations in Implants

2. CONTENTS
1. Introduction
2. Imaging Objectives
3. Imaging Modalities
4. Pre-surgical Imaging
5. Imaging of vital structures
6. Intra-operative Imaging
7. Fabrication of Diagnostic template
8. Radiographic signs associated with failing endosseous implants
9. Conclusion
10. References

3. • In the present era when it comes to oral rehabilitation, a wide range of options are
available to restore the missing teeth using fixed or removable prosthesis.
• The advent of implants in the field of dentistry has given dental professionals a viable
option to provide the patients with early third set of dentition.
INTRODUCTION

4. Diagnostic Options range from
1) Standard projections (routinely available)
• Intraoral (periapical, occlusal)
• Extraoral (panoramic, lateral cephalometric) r/g’s
2) More complex imaging techniques in the dental office
• Conventional x-ray tomography
• Computed tomography (CT), and
• Cone-beam CT (CBCT)
***Diagnostic imaging techniques must always be interpreted in conjunction with a good
clinical examination.
To

5. PHASES OF IMAGING
Phase- II
Surgical &
intraoperative
implant
imaging
Phase- III
Post-prosthetic
imaging
Phase- I
Pre-surgical
implant
imaging

6.  Involves all past and new R/G examinations to determine the patient's final treatment
plan.
Objectives
1. To assess the overall status of the remaining dentition.
2. To identify and characterize the location and nature of the edentulous regions,
particularly to determine the quantity , quality and angulations of bone.
3. To determine the relationship of critical structures to the implant site.
4. To detect regional anatomic structures.
5. To determine the presence or absence of disease at the implant site.
1) Pre-surgical implant imaging

7. • Assists in the surgical and prosthetic intervention of the patient.
Objectives
1. To evaluate the surgical site during & immediately after surgery.
2. Assist in the optimal position and orientation of dental implants.
3. To evaluate the healing and integration phase of implant surgery.
4. To ensure that abutment position and prosthesis fabrication are correct.
2) Surgical & intra-operative implant imaging

8. • Commences just after the prosthesis placement and continues as long as the implant
remains.
Objectives
1. To evaluate the long-term maintenance of implant rigid fixation and function.
2. To assess the Crestal bone levels around each implant.
3) Post-prosthetic imaging

9. IMAGING MODALITIES
Can be:
 Analog imaging - 2-D systems  uses radiograph films or
intensifying screens
 A digital 2-D image - is an image matrix with individual picture
elements (pixels)
 A digital 3-D image - is an image matrix with individual volume
elements (voxels)
- is described not only by its width &
height but also by its depth/ thickness
Analog / Digital 2-D/ 3-D

10. Analog 3-D
1. Periapical Radiography
2. Panoramic Radiography
3. Occlusal Radiography
4. Cephalometric Radiography
1. Tomographic Radiography
2. Computed Tomography
3. Magnetic Resonance Imaging
4. Interactive Computed
Tomography

11. S no. TYPES EXAMPLES FUNCTION
1. PLANAR 2-
DIMENSIONAL
Periapical, Bite-wing, Occlusal
and Cephalometric imaging
Gives a 2-d projection of
patient's anatomy
2. QUASI-3-
DIMENSIONAL
X-ray tomography, Cross-
sectional Panoramic imaging
Gives a 3-d perspective of
patient's anatomy
3. 3-DIMENSIONAL CT and MRI Gives the dentist to view
the volume of the patient's
anatomy.

12. 1. Direct systems: CCD (charged coupled device) & CMOS (complementary metal
oxide semi-conductor) solid-state sensors contain silicon crystals converting photons to
electrons.
2.Indirect systems: Photostimulable storage phosphor (PSP) plates resemble the thin &
small intraoral films.
 can be designed into similar formats of occlusal sizes, and therefore better tolerated
by patients.
CCD CMOS
pixel charges are transferred to a common
output source.
conversion takes place at each pixel.
IMAGE RECEPTOR

13. PRESURGICAL IMAGING
Recommended principle  ALARA Principle.
“As Low As Reasonably Achievable”

14. 1. PERIAPICAL RADIOGRAPHY
• Film is placed parallel to the body of the alveolus.
• The central ray of the x-ray device - perpendicular to the alveolus at the site .
• Produces a lateral view of the alveolus, but no cross-sectional information

15. • Low radiation dose
• Minimal magnification (with proper alignment and positioning)
• High resolution
• Inexpensive
ADVANTAGES
• Distortion and magnification (compared with 3-D)
• Minimal site evaluation, 2-D representation
• Difficulty in film placement, BL width assesment—not possible
• Technique sensitive
LIMITATIONS
• Evaluation of a small area
• Alignment and orientation during surgery
• For recall and maintenance therapy
INDICATIONS

16. PARALLELING TECHNIQUE
• Less magnification when there is a
greater distance between the x-ray
source and the film with the film being
as close to the tooth as possible.
BISECTING ANGLE TECHNIQUE
• . This technique results in decreased
exposure time.

17. Increasing image quality -
• Use smallest focal spot possible
• Increase the distance between the x-ray source and the film.
• Place the film- as close & parallel to the object as possible (e.g. tooth).
• X-rays  perpendicular to the film.

18. BUCCAL OBJECT RULE:
• Used to determine the buccolingual relationship of an object in relation to a second
object i.e to determine if the object (e.g. artifact) lies buccal or lingual to the second
object (e.g tooth)
• The protocol is to take two separate images at two different angles.

19. • The first image is made straight on, while the second image- at an angle more toward the
mesial or distal.
• By comparing the two images, you can decipher the relationship using this simple rule:
SLOB = Same Lingual, Opposite Buccal
• If you take the second image from a more mesial angle, if the object moves more mesial as
well (or in the Same direction), then the object is buccal to the second object.

20. DIGITAL RADIOGRAPHY(RVG)
• 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:
1. Charge-coupled device (CCD)
2. Complementary metal oxide semiconductor / active pixel sensor (CMOS/APS)
3. Charge injection device (CID)
Digital
radiographic
system that
includes digital
sensor and
computer.

21. • Less radiation because the sensors are more sensitive (exposure times 50-
90% less).
• Immediate result
• Ability to enhance the images (which can lead to more effective diagnoses)
• Patient education is better because the dentist is able to show things easier
• You don’t need a processor, chemicals, special rooms, film, etc.
Advantages
• High initial start-up costs
• Learning curve (the staff and the doctor must be trained on how to take,
view, and manipulate the radiographs)
• 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)
Disadvantages

22. • Maxillary occlusal view  is oblique and so distorted that they are of no
quantitative use for implant dentistry for determining the geometry or the degree of
mineralization of the implant site.
• Mandibular occlusal radiograph is an orthogonal projection, it is less
distorted projection than the maxillary occlusal r/g.
OCCLUSAL RADIOGRAPHY

23. Maxillary occlusal view Mandibular occlusal view
ADVANTAGE
• Evaluation for pathology
LIMITATIONS
• Does not reveal true
buccolingual width in
mandible

24. • The skull is oriented to the x-ray device using a cephalometer.
• Fixes the position of the skull with the projections into the external auditory canal.
• Mid-sagittal plane oriented parallel to the image receptor.
• Helps to determine The width of bone in the symphysis region and the relationship
between the buccal cortex and the roots of the anterior teeth before harvesting this bone
for ridge augmentation
CEPHALOMETRIC RADIOGRAPHY
Not useful for demonstrating bone quality and only demonstrates a cross sectional
image of the alveolus

25. ADVANTAGES
• Height/width in anterior region
• Low magnification
• Skeletal relationship
LIMITATIONS
• Technique sensitive
• Image information is limited to ant.
region.
INDICATIONS
• Used in combination with other techniques
for anterior implants.
• Symphysis bone graft evaluation.

26. PANORAMIC RADIOGRAPHY
• A curved plane tomographic technique used to depict the body of the mandible, the
maxilla, and the lower half of the maxillary sinuses in a single image.
• Image receptor: radiographic film/ digital storage phosphor plate/ digital CCD
• Equipment horizontal rotating arm which holds an X-ray source and a
moving film mechanism (carrying a film) arranged at opposed extremities.
 The patient's skull sits between the X-ray generator and the film.
 The X-ray source is collimated toward the film, to give a vertical
blade beam shaped (width of 4-7mm when arriving on the film, after crossing the
patient's skull)

27. • Height of that beam covers the mandible and the maxilla regions.
• The arm  rotates around an instant center which shifts on a dedicated trajectory.
• The posterior maxillary regions  the least distorted regions in OPG
• The tomographic section thickness of panaromic radiograph or trough of focus is thick,
approximately 20mm, in the posterior regions and thin 6mm, in the anterior regions.
All panoramic beam angles
are approximately at 8
degrees, which gives the image
inherent magnification
Because of the curvature of the
arch, panoramic machines have
changing rotational centers.

28. LIMITATIONS
Distortions
Errors in
patient
positioning
Does not
demonstrate
bone quality.
Misleading quantitate
because of
magnification and no
third dimension
No spatial
relationship
between
structures
ADVANTAGES
Easy
identification
of opposing
landmarks.
Initial assessment
of vertical height
of bone.
Convenience, ease,
and speed in
performance in most
dental offices.
Evaluation of gross
anatomy of the jaws
and any related
pathological findings.

29. FOCAL TROUGH
• Invisible area (3D curved zone) in which structures are clearly
demonstrated on a panoramic radiograph.
• Also called – plane of acceptable detail or image layer.
• Structures  within the focal trough  well defined
 outside focal trough.  blurred.
• Narrow anterior region and
• Wide posterior region.

30. 0

31. PROBLEM CAUSE CORRECTION
Blurred Magnified Patient positioned too far
posterior
Make sure anterior teeth
are properly in the holder
Blurred Narrow anterior region Patient positioned too far
anterior
Make sure anterior teeth
are in holder
Flattened curve of Spee; Hard palate
superimposed
Patient chin tipped too far
upward
Correctly align ala-tragus
Radiopaque shadow over anterior
region
Patient slumped too far
forward
Straighten neck
Ramus larger on one side uneven
pattern of blurring
Patient head rotated in
machine
Patient midsagittal plane
should be perpendicular to
the floor
Large radiolucency over maxilla Patient tongue not in floor of
mouth
Patient place tongue on
roof of mouth, swallows

32. TOMOGRAPHY
• Greek word  Tomo (slice) and graph(picture)
• X-ray and the film are connected by a rigid bar called the fulcrum bar, which pivots on a
fulcrum point.
• 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 tomographic layer.
PRINCIPLE

33. CONVENTIONAL TOMOGRAPHIC IMAGES
Indications-
• Single-site
evaluation
• Vital structures
evaluation
Advantages-
• Cross-sectional
views
• Constant
Magnification
Limitations-
• Availability
• Cost
• Multiple Images
• Technique
sensitive
• Blurred images
• High radiation

34. COMPUTED TOMOGRAPHY
• Non-invasive Digital & mathematical imaging that creates tomographic sections
• Enables differentiation of soft & hard tissues.
• Invented by Hounsfield (1972).
• Produces axial images perpendicular to long axis of body.

35. The x-ray source is attached to a fan-beam geometry detector
array, which rotates 360 degrees around the patient.
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 first to produce CT images.
CT images are inherently three-dimensional digital images,
typically 512X512 pixels with a thickness described by the slice
spacing of the imaging technique.
The original imaging computer can create secondary images from
almost any perspective by reprojecting or reformatting the original
3D voxel data

36. • The individual element of the CT image is called a voxel, which has a value, referred to in
Hounsfield units, that describes the density of the CT image.
• The density of structures within the image is absolute and quantitative and can be used to
differentiate tissues in the region and characterize bone quality.
Muscle 35–70 HU
Fibrous tissue 60–90 HU
Cartilage 80–130 HU
Bone 150–1800 HU
D1 bone >1250 HU
D2 bone 750–1250 HU
D3 bone 375–750 HU
D4 bone <375 HU

37. COMPUTED TOMOGRAPHY
INDICATIONS
• Interactive treatment
planning
• Determination of bone
density
• Vital structure location
• Determination of
pathology
• Preplanning for bone
augmentation
ADVANTAGES
• Negligible
magnification
• Relatively high-contrast
image
• Various views
• Three-dimensional bone
models
• Interactive treatment
planning
LIMITATIONS
• Cost
• Technique sensitive

38. CONE BEAM VOLUMERIC TOMOGRAPHY
CBVT
• The first CBVT scanner in dentistry NewTom QR-DVT 9000 and NewTom 3G.
(latest version)
• The x-ray tube rotates 360 degrees capture images of the maxilla and mandible in 36
seconds, requiring only 5.6 seconds for exposure.
• The images recorded are placed onto a CCD chip with a matrix of 752 x 582 pixels then
converted into axial, sagittal, and coronal slices permit reformatting to view traditional r/g
images & 3-D soft tissue/ osseous images.

39. CONE-BEAM COMPUTED TOMOGRAPHY
CBCT
• Introduced to dentistry in the late 1990’s.
• The difference between CBCT and CT is the shape of radiation beams and the
mode of motion.
• CT - fan-beam and CBCT- a cone-shaped x-ray beam (which images a larger area
 Thus, at the end of a single complete rotation, 180 to 500 images of the area are
generated).
• The computer uses these images to generate a digital, 3-D map of the face.

41. CS 3D Imaging software

43. INTERACTIVE COMPUTED TOMOGRAPHY
• Enables a) the radiologist to transfer the imaging study in a computer file &
b) the practitioner to view with the imaging study on a personal computer.
Interactive computer guided implantology using NobelGuide software system

44. The first step  impressions for study casts.
a diagnostic wax-up
Fabrication of a radiopaque template
• will allow the transfer of the ideal positioning of the
teeth.
Acrylic template along with the plaster
model.
Arrows indicate the radiopaque
markers of the proposed implant area.

45. • For conventional and CT the positioning of the teeth is integrated into a scanning template
by way of a radiopaque material.
• Accomplished by way of an acrylic template coated with barium sulfate, gutta percha
markers or radiopaque denture teeth.
• These radiopaque templates may then be modified into use for surgical templates

46. Implant placement in relation to the mandibular canal and mental foramen; all images
are cross-referenced with each other.
Three dimensional analysis for the evaluation of proximity to vital structures may be
generated from the same computed tomography images

47. CT-BASED SURGICAL GUIDANCE
TEMPLATES AND NAVIGATION SYSTEMS
• Advanced technology has introduced guidance systems to facilitate dental implant
placement procedures during surgery.
• 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 the drilling sequence is made to the exact location of
the preplanned position.

48. MAGNETIC RESONANCE IMAGING
• Introduced by Lauterbur
• Produces images of thin slices with excellent spatial resolution
• Uses combination of magnetic fields to generate images without
the use of ionizing radiation.
• Adv.  flexibility in the positioning & angulation of image
sections
 can produce multiple slices simultaneously

49. • The images created by MRI are the result of signals created by hydrogen protons in water
or fat such that :
1. Cortical bone  appear black (radiolucent)/ as having no signal
2. Cancellous bone  will generate a signal & will appear white (fatty marrow)
• Metal restorations do not produce scattering  thus appear black images.
• Advantages  quantitatively accurate technique with exact tomographic sections & no
distortion

50. • In cases where the inferior alveolar canal cannot be differentiated by conventional or
computed tomography, MRI would be a viable alternative as the trabecular bone is
easily differentiated with the inferior alveolar canal
• In cases of nerve impairment or infection, MRI may be used because of added
advantages including differentiation of soft tissue with respect to CT
• secondary imaging technique when primary imaging techniques (such as complex
tomography or CT) fail
Uses:-

51. Advantages
• No radiation
• Vital structures are
easily seen
Uses
• Evaluation of vital
structures when
computed tomography
is not conclusive
• Evaluation of infection
Limitations
• Cost
• Technique sensitive
• No reformatting
technique
• Availability
• Non-signal for cortical
bone
• Not useful in
characterizing bone
mineralization or as a
high-yield technique
for identifying bone or
dental disease

52. ADVANTAGES AND DISADVANTAGES OF THE VARIOUS
RADIOGRAPHIC PROJECTIONS
Modality Advantages Disadvantages
Periapical and occlusal
radiography
- High resolution and detail
- easy acquisition,
- low exposure
- inexpensive.
-Unpredictable magnification
-small imaged area,
-2D representation of
anatomy
Panoramic radiography
-Easy to acquire, images
whole ridge
-low exposure,
-inexpensive.
-Unpredictable magnification
-2D representation of
anatomy, not detailed

53. Modality Advantages Disadvantages
Lateral cephalometric
radiography
-Easy to acquire,
-predictable magnification
-low exposure
-inexpensive.
-Limited use in area of
midline
-2D representation of
anatomy
Tomography
-3D representation,
-predictable magnification,
-sufficient detail,
-low exposure,
-images area of interest only.
-Requires special equipment,
-for evaluation of multiple
sites can be a lengthy
procedure because the
patient must be repositioned
for each site,
-expensive

54. Modality Advantages Disadvantages
Computed tomography (CT)
-3D representation,
-predictable magnification,
-sufficient detail,
-digital format,
-images whole arch.
-Requires special equipment,
-expensive,
-high-exposure dose
Cone-beam computed
tomography (CBCT)
-3D representation,
-predictable magnification,
-sufficient detail,
-digital format,
-images whole arch,
-low dose.
-Requires special equipment
-expensive

55. ANATOMIC STRUCTURES PERTINENT TO TREATMENT
PLANNING OF THE IMPLANT PATIENT
Maxilla
1. Maxillary sinus (floor & anterior
wall)
2. Nasal cavity (floor & lateral wall)
3. Incisive foramen
4. Canine fossa
Mandible
1. Mandibular canal
2. Mental foramen
3. Submandibular fossa
4. Lingual inclination of the
alveolar ridge

56. R/G IMAGING OF VITAL STRUCTURES
Mental Foramen And Mandibular Canal
• Identified to avoid trauma to the inferior alveolar nerve & mental nerve
• Because of the curvature of the mandible, care must be given to the angulation of the x-ray
beam for intraoral radiography.

57. • For IOPA’s & OPG- If the image is taken from orientations:-
1. Mesio-oblique foreshortened and
2. Distal-oblique elongated.
• In edentulous mandible, the risk of error increases in resorbed
alveolar crest.
 Most accurate means of identification is with conventional
& computerized tomography.
 Tilting the patient’s head approximately 5 degrees
downward in reference to the Frankfort horizontal plane
allows these anatomical structures to be seen in 91% of
radiographs.(Dharmar S)

58. Mandibular Lingual concavities
• Usually seen in advanced atrophy in posterior mandible.
• Overestimation of the amount of bone perforation of the lingual plate when drilling.
• Lingual bleeding problems - can be life-threatening.
• Technique of choice cross-sectional tomography

59. Mandibular Ramus
• popular donor site for autogenous onlay bone grafting.
• 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.

60. Mandibular Symphysis
• critical anatomical area.
• A common position for implants in mandibular
edentulous patients
• donor site for autogenous grafting.
• With 2-D imaging inherent errors due to lingual
concavities.
• R/g’s  lateral cephalometric and conventional CT,
may be used.
Computed tomography images illustrate
various views of the mandibular anterior
region.

61. Maxillary Sinus
• CT gold standard.
• provides detailed information –
1. Prevalence and position of septa
2. Maxillary sinus anatomy
3. Detection of sinus pathology

62. • With digital radiography technology, instantaneous images are achieved, allowing for
multiple images to be completed in a fraction of the time.
• Additional advantages –
Manipulation of images
Calibration
Accurate positioning
Maintenance of aseptic protocol
INTRAOPERATIVE IMAGING

63. Initial pilot
orientation with
slight mesial
inclination
Angulation
corrected and
verified with final
depth indicator
Implant placement.
Note poor angulation of
radiograph leading to
distorted measurements.
Ideal implant placement
radiograph.
Due to the perpendicular
orientation of x-ray
beam all threads are
seen without distortion

64. IMMEDIATE POSTSURGICAL IMAGING
• A 2-D imaging is done to obtain a baseline image that may be used to evaluate
against future films
• Additional imaging tools may be used to evaluate a zone of safety around vital
structures.
Abutment and Prosthetic Component Imaging
 Transfer impressions with two-piece abutment component placement
radiographs should be taken to verify secure adaptation.
 When positioning is difficult for periapical radiographs, bitewing or panoramic
radiographs may be used.
Verification of
direct transfer
coping
placement
before final
impression.
Note ideal
angulation
from thread
alignment

65. RECALL & MAINTENANCE IMAGING
• Done for-
1. For marginal bone level evaluation.
• For investigating complications after implant placement the image of choice.
Panoramic r/g  multiple implants & Periapical r/g single implants
 Immobility and Radiographic evidence of bone adjacent to the implant are the two most
accurate diagnostic aids in evaluating success.
 Follow-up or recall radiographs  taken after 1 yr of functional loading and yearly for
the first 3 years.
 marginal bone loss and a higher rate of failure are seen - in the first 6 months.
POST-PROSTHETIC IMAGING

66. • R/g-- loss of integration is indicated as a radiolucent line around the implant.
1. false-negative dx- when the soft tissue surrounding an implant is not wide enough
to overcome the resolution of the radiographic modality used.
2. false-positive dx- when a “Mach band effect” results from an area of lower
radiographic density adjacent to an area of high density (implant), which results
in a more radiolucent area than is actually present.
Digital radiography has the advantage of “edge enhancement (ability to detect space
between the implant and the surrounding bone).”
EVALUATION OF ALVEOLAR BONE CHANGES

67. PERIAPICAL RADIOGRAPHS
• In recall IOPA’s the marginal bone level is compared with the immediate post-prosthetic
r/g.
Alveolar bone level evaluation.
A- Ideal positioning showing ideal thread orientation.
B, Improper angulation showing diffuse thread
orientation.
If the implant threads are not clearly seen in the
r/g’s
Modify the beam angle
If diffuse threads are present on the right side of
the implant
beam angle was positioned too much in the
superior direction.
If the threads are diffuse on the left side then the beam angle was from an inferior
angulation

68. BITEWING RADIOGRAPHS
• In cases where the x-ray source cannot be positioned perpendicular to the implant because of
oral anatomy or existing prosthesis, horizontal or vertical bitewings are taken to evaluate the
crestal bone area.
• Limitation  apical portion cannot be seen.
 2 r/g’s taken at different times superimposed on one another gives an image
that exhibits the differences in the bone level.
 ***requires same positioning and imaging technique between the two radiographs
with respect to the x-ray source, patient and film position, exposure, and
processing variables.
DIGITAL SUBTRACTION RADIOGRAPHY

69. PANORAMIC RADIOGRAPHS
• The images are substracted and the resultant image left
depicts the osseous changes between the r/g’s.
• More accurate  accessing bone mineralization and
volume changes
 Not used routinely for evaluation of osseous bone levels
and recall as they use intensifying screens poor
resolution.
 Technique of choice- when multiple implants need to be
evaluated.

70. COMPUTED TOMOGRAPHY
• D/A of 2-D r/g’s do not give buccolingual condition of alveolar bone.
• CT gives 3-D information about the osseous status around an implant.
• Adv  bone density evaluation using Hounsfield unit that helps determine bone
maturation.
• D/A Resolution and scattering overcome with cone beam technology.
• Image of choice for evaluation of sinus infection/ postsurgical sinusitis
complications

71. FABRICATION OF DIAGNOSTIC TEMPLATES
• The purpose  to incorporate the proposed treatment plan into the radiographic
examination.
• Steps:-mounted diagnostic casts a diagnostic wax-up template fabrication.
• The pre-prosthetic imaging enables evaluation of the proposed implant site at the ideal
position and orientation.

72. COMPUTED TOMOGRAPHY TEMPLATE
• Designs for diagnostic CT templates have evolved from
one produced
from a processed
acrylic
reproduction of
the diagnostic
wax-up

73. • The acrylic template is 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 seen as radiopaque in the CT
examination.
A - A vacuum-formed imaging stent with a metal rod to indicate desired axis of
insertion.
B - A processed stent with metal cylinders marking the implant sites. This can also be
used as a surgical stent by inserting the guide bur through the cylinders.
C - A processed stent with insertion axis markers, along with a radiopaque strip
outlining the buccal and lingual contours of the planned restoration. The stent
provides an image of the emergence profile of the restored implant and can also be used
as a surgical guide.

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
• Time saving
• Easily placed
• Provide high radiopacity
• Bond easily with the
template.
Dov , Almog, Romano PR. CT-Based Dental Imaging for Implant Planning and
Surgical Guidance A CASE REPORT. New York state dental journal. 2007

75. TOMOGRAPHY TEMPLATE
• The simplest tomography template is obtained by a vacuform of the patient’s diagnostic
cast with 3-mm ball bearings.
• A number of tomograms of the implant region are produced with the implant site
identified by the one in which the ball bearing is in sharp focus.
• It can also serve as a measure of the magnification of the imaging system.

76. 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

77. RECENT ADVANCES

78. DIGITAL IMAGING
NOBEL PROCERATM

79. TUNED APERTURE COMPUTED TOMOGRAPHY
(TACT)
• In this technique image is produced by
passing a radiographic beam through an
object several different angles.
• Advantages :
 it can accommodate patient movement
during firing with affecting the quality of
the image produced with reduced
radiation dose.
 Localization of bone disease, anatomical
structures and abnormalities at implant
site is much easier with TACT.

80. • A modification of the panoramic x-ray machine for
making cross-sectional images of the jaws.
• The tomographic layer is approx. 5mm.
• For appreciation of spatial relationship between the
critical structures and the implant site.
• Limitations :
Tomographic layers are relatively thick.
Adjacent structures blurring and superimposed.
Not useful for determining the differences in bone
density or for identifying disease at implant site.
ZONOGRAPHY

82. • Provides programmed reformation, organization and
display of the imaging study.
• The curvature of the mandibular or maxillary arch is
selected, & the computer is programmed to generate
referenced cross-sectional and tangential/panoramic
images of the alveolus along with 3-D images of the
arch.
Axial CT view of the mandible
showing the potential
crosssectional slices that can be
reformatted by Dentascan.
Limitations:-
1. not true size images and requires compensation for magnification
2. Determination of bone quality requires workstation
3. Hard-copy only include a limited range of the diagnostic grayscale
4. Tilt of the patient’s head during the examination, which is critical because all the cross-
sectional images are perpendicular to the axial imaging plane.
DENTASCAN

83. SIMPLANTS
• It is an interactive dental implant software package.
• It allows dentists to view and manipulate processed CT images.
• Simplant software can be used to superimpose images of actual size
implants on the CT images for treatment planning.

84. • Radiographs play an important part in the successful planning and execution of
implant treatment.
• They are an important part of the patients records and as such constitute a
significant proportion of the medico-legal documentation of the patient.
• It is important to have an understanding of the different techniques available and
their appropriate application.
• It is the responsibility of the clinician to ensure that radiographs are appropriate,
readable and are retained and repeated at accepted intervals throughout treatment
and follow-up.
CONCLUSION

85. 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
REFERENCES

86. THANK-YOU !