This document provides an overview of radiographic techniques and interpretations in endodontic diagnosis. It discusses the history of dental radiography and various radiographic techniques including intraoral periapical, bitewing, occlusal, tomography, computed tomography, cone beam computed tomography, scanography, stereography, magnetic resonance imaging, digital subtraction radiography and direct digital radiography. It also covers interpreting dental caries, trauma, pulpal and periapical lesions, restorations and dental materials, and root canal anatomy on radiographs. The document emphasizes that cone beam computed tomography is more accurate than conventional radiography for detecting vertical root fractures in teeth with metallic posts.

2. RADIOGRAPHIC
INTERPRETATIONS IN
ENDODONTIC
DIAGNOSIS
Liya Alice Thomas

3. CONTENTS
Introduction
History
Terminology
Radiographic techniques
Interpretation of dental caries
Interpretation of trauma, pulpal & periapical lesions
Interpretation of restorations & dental materials
Interpretation of root canal anatomy
Conclusion
References

4. INTRODUCTION

5. HISTORY
•Feb 1895 – discovery of cathode rays by Prof. Wilhelm Roentgen
•14 days later – Dr.Otto Walkoff took the first dental X-ray in his own mouth
•3 months later – Dr.C. Edmund Kells installed the first X-ray machine in his clinic
•1899 – Dr. C.Edmund Kells used X-rays for working length determination (FATHER
OF DENTAL RADIOLOGY)
•1900 – Dr. Weston Price used radiographs to detect inadequately filled root canals.
developed bisecting angle technique.

6. TERMINOLOGY
•IMAGE INTERPRETATION – An explanation of what is viewed on a dental
image <or> the ability to read what is revealed by a dental image
•DIAGNOSIS – The identification of a disease by examination or analysis

7. APPLICATION OF
RADIOGRAPHY IN
ENDODONTICS1. Diagnosis of hard tissue alterations of teeth & periradicular structures
2. Determine the number,location,shape,size & direction of roots & root canals
3. Estimate & confirm length of canals
4. Localize hard-to-find pulp canals by examining the position of an instrument within the root
5. Determine relative position of structures in the facial-lingual dimension
6. Confirm position & adaptation of master cones
7. Aid in evaluation of obturation
8. Facilitate the examination of soft tissues for tooth fragments & other foreign bodies
following trauma
9. Evaluate, in follow up films, the outcome of treatment

8. LIMITATIONS OF
RADIOGRAPHS1. Can be easily distorted through improper technique, anatomic limitations or processing errors
2. Buccal-lingual dimension is absent on a single film
3. Various states of pulpal pathosis are indistingushable.Neither healthy nor necrotic pulps cast
an unusual image
4. The bacterial status of hard or soft tissue is not detectable-microbiological inference
5. Periradicular soft tissue lesions cannot be diagnosed accurately-histological inference
6. C/c inflammatory tissue cannot be distinguished from healed, fibrous scar tissue
Goldman M,Pearson A,Darzenta N.Endodontic success-who’s reading the radiograph? Oral Surg Oral Med Oral
Pathol Oral Radiol Endod 1972;23:432

9. TYPES OF IMAGING TECHNIQUES
CONVENTIONAL SPECIALIZED
1. Intraoral periapical
radiograph
2. Bitewing radiographs
3. Occlusal radiographs
1. Tomography
a)Conventional
b)Computed
c)Three dimensional
2. Scanography
3. Stereoscopy
4. Magnetic resonance imaging
5. Digital subtraction radiography
6. Digital radiography
7. Xeroradiography
8. CBCT

10. INTRAORAL
PERIAPICAL
RADIOGRAPH
A periapical X-ray is a specific type of intraoral X-ray that
is used to investigate the structural integrity of an individual
tooth. A periapical X-ray provides an image of a tooth from
the tooth’s crown to the tip of its root.
Periapical X-rays provide a more highly focused, finely
detailed image than the bitewing radiograph
CONVENTIONAL RADIOGRAPHS

11. BITEWING RADIOGRAPH
They show the crowns of maxillary and mandibular
teeth along with the alveolar crests
Mainly used in the detection of proximal caries and
to check the cervical margins of restorations

12. OCCLUSAL RADIOGRAPHS
designed to provide a more extensive view of
the maxilla and mandible.
USES :
1.determining the buccolingual extension of
pathologic conditions
2.provides additional information as to the extent
and displacement of fractures of the mandible and
maxilla.
3.localizing unerupted teeth, retained roots, foreign
bodies, and calculi in the submandibular and
sublingual salivary glands and ducts

13. SPECIALIZED RADIOGRAPHS
CONVENTIONAL TOMOGRAPHY
Synchronized movement of the film & tube in
opposite directions about a fulcrum ( ie the
plane of interest in the patient’s body)
Objects close to the film are clear.objects
further away are blurred
USES :
1.Precise evaluation of sinus pathologies
2.Used to study facial fractures
3.Evaluation of dental implants
4.In diseases of the TMJ

14. COMPUTED TOMOGRAPHY
Uses x-rays to produce sectional images
but the radiographic film is replaced by
sensitive crystal or gas detectors which
measure the intensity of x-ray beam and
convert it into digital data
USES :
1)Assessment of maxillofacial fractures
and tumors
2)Assessment of TMJ
3)Detecting salivary gland pathosis
4)Preoperative assessment of alveolar
bone height & thickness before placing
implants

15. THREE DIMENSIONAL CT
Computer program that reformats
the acquired data from axial CT
scans and converts it into a three
dimensional image
USES:
1)Craniofacial reconstructive
surgery
2)Evaluation of maxillofacial tumors
3)Proper implant design &
placement

16. CONE BEAM COMPUTED
TOMOGRAPHY
•more efficient and economical than
either conventional tomography or
computed tomography
•CBCT uses a round or rectangular
cone shaped x ray beam centered on a
2-dimentional x ray sensor to scan a
360 degree rotation about the patients
head
•The radiation dose delivered to the
patient as a result of one CBCT IS 20%
LESS that of conventional CT scan
Comparison of periapical radiography with cone beam
computed tomography in the diagnosis of vertical root
fractures in teeth with metallic post
Journal of conservative dentistry Year : 2014 Volume :
17 Issue : 3 Page : 225-229

17. Comparison of periapical radiography with cone beam computed tomography in the
diagnosis of vertical root fractures in teeth with metallic post
Aim: To compare the diagnostic accuracy of conventional periapical radiography and cone
beam computed tomography (CBCT) in detecting vertical root fracture (VRF) in tooth with
metallic post (MP).
Materials and Methods: Twenty endodontically-treated teeth received MPs, artificial
fractures were created in 10 teeth, and they were all examined with tomography and
radiography. The sample consisted of periapical radiography with post and without post,
and tomography with post and without post; each group with five fractured and five non-
fractured teeth. The images were evaluated by three dental/maxillofacial radiologists and
statistical validations were carried out using receiver operating characteristic (ROC)
analysis.
Results: Sensitivity and specificity of the area under the ROC (Az) of tomography with post
(Az = 0.953) and without post (Az = 0.956) were significantly higher than those of
periapical radiography with post (Az = 0.753) and without post (Az = 0.778).
Conclusion: CBCT was more accurate than conventional periapical radiography in
detecting VRF.

18. SCANOGRAPHY
 Uses a narrowly collimated fan
shaped beam of radiation to scan an
area of interest sequentially
projecting image data relative to this
area onto a moving film
 Higher contrast & better details

19. STEREOGRAPHY
Requires the exposure of two films
one for each eye as the tube is
shifted to 10% of focal film distance
Then they are viewed with
stereoscope that uses either mirrors
or prisms to coordinate the
accommodation
USES :
1.Evaluation of bony pockets in
periodontal diseases
2.TMJ evaluation
3.Status of dental implants
4.Root configurations

20. Stereographic assessment vs.clinical assessment of mandibularcanal in
relation to the roots of impacted lowerthird molar
The position of the mandibular canal in relation to the superimposed roots of
173 impacted lower 3rd molars was evaluated radiologically. Stereography
technique recently developed for oral radiography was applied in this study.
The mandibular canal was located buccally to the roots of 105 (61%) teeth,
lingually to the roots of 57 (33%) teeth, and between the roots of 6 (3%)
teeth. The relationship of canal to roots of 5 (3%) teeth was not possible to
determine.
Disagreement between radiological assessment and clinical observation was
found in 4 (5%) of 80 operated teeth. The canal was visible at operation in 23
(29%) cases, which was predicted at stereographic examination in 21(91%)
cases.
The stereographic technique is a useful method with high sensitivity (0.83)
for evaluating the bucco-lingual relationship of the mandibular canal to the
roots of a 3rd molar.
International Journal of Oral and Maxillofacial Surgery Volume 21, Issue 2, April 1992, Pages

21. MAGNETIC RESONANCE
IMAGING
• Relies on the phenomenon of
nuclear magnetic resonance to
produce a signal that can be used
to construct an image
• Uses nonionizing radiation
• USES :
1. Assessment of intracanal lesions
2. Tumor staging in salivary
glands,pharynx & larynx
3. Investigations of TMJ

22. XERORADIOGRAPHY
• Based on an electrostatic process
similar to that used for Xeroxing
• Image is captured on an aluminium
plate coated with selenium particles
• The various features that make it an
attractive diagnostic aid are-
1.Better edge enhancement
2.High contast
3.Positive & negative displays
• USES :
1. Determine height of alveolar ridge
2. Detection of caries
3. endodontics

23. DIRECT DIGITAL RADIOGRAPHY
In this digital image is formed
which is represented by
spatially distributed set of
discrete sensors & pixels
PHOSPHOR IMAGING SYSTEM :-
•Image is captured on a phosphor plate as
analogue information & converted into digital
format when plate is processed

24. RVG :-

25. DIRECT SUBTRACTION
RADIOGRAPHY
• Images which are not of
diagnostic value in a radiograph
are reduced so that the changes
in the radiograph can be
detected.
• two standardized radiographs
are produced.first-REFERENCE
IMAGE & the second is taken
for comparison after a period of
time.
• Both images are superimposed
and difference is detected
• USES :
1.Assess progression/regression
Subtraction radiography. The image to the right is the
result of the subtraction of the second image from the
first image. Note the dark area indicating bone loss (red
arrow) that was not visible on the original image.

26. INTERPRETATION OF DENTAL
CARIES
Cariosus (LATIN) - rottenness

27. CLASSIFICATION OF CARIES ON DENTAL RADIOGRAPHS
INTERPROXIMAL
CARIES

28. INCIPIENT INTERPROXIMAL
CARIES
MODERATE INTERPROXIMAL
CARIES
ADVANCED INTERPROXIMAL
CARIES
SEVERE INTERPROXIMAL
CARIES

29. OCCLUSAL CARIES
INCIPIENT CARIES MODERATE CARIES SEVERE CARIES

30. BUCCAL & LINGUAL
CARIES
ROOT SURFACE
CARIES

31. CERVICAL BURNOUT
 Root
configuration
 Shape of
cemento-
enamel junction
 Exposure
factors

32. MACH BANDS
• Mach bands is an optical illusion
• Exaggerates the differences between
neighbouring areas of slightly differing shades of
gray along the boundaries, thus enhancing edge-
detection by the human visual system.
• A false-positive radiological diagnosis of dental
caries can easily arise if the practitioner does not
take into account the likelihood of this illusion. Not
only do Mach bands manifest adjacent to metal
restorations or appliances, but they can also
present at the boundary between enamel
and dentin .
• Mach bands may also result in the misdiagnosis
of horizontal root fractures because of the
differing radiographic intensities of tooth and
bone

33. RECURRENT CARIES
RAMPANT CARIES

34. INTERPRETATION OF TRAUMA, PULPAL AND PERIAPICAL LESIONS

35. FRACTURES
CROWN FRACTURES
TRAUMA
Enamel fracture
Enamel-dentin
fracture
Enamel-dentin-pulp
fracture

36. Crown-root fracture without pulpal
involvement
Crown-root fracture with pulpal involvement

37. ROOT FRACTURES
HORIZONTAL ROOT
FRACTURE
VERTICAL ROOT
FRACTURE
A)At one year recall there is no
evidence of any radiographic changes
which are suggestive of a problem
B)Two years later there is widening of
the periodontal ligament space & the
appearance of a large periapical
lesion.the fracture is seen as a space
which has developed on the distal side
of the filling due to slight separation of
the fragments
Moule AJ, Kahler B. Diagnosis and management of teeth with vertical root fractures Australian Dental Journal 1999; 44(2): 75-87

38. ALVEOLAR FRACTURE

39. LUXATION
INTRUSIVE LUXATION EXTRUSIVE LUXATION SUBLUXATION

40. AVULSION CONCUSSION

41. RESORPTION
PHYSIOLOGIC PATHOLOGIC
INTERNAL EXTERNAL
Root canal replacement
Internal inflammatory
External surface resorption
External inflammatory
Apical replacement

42. PHYSIOLOGIC RESORPTION

43. PATHOLOGIC RESORPTION
EXTERNAL RESORPTION
A ) EXTERNAL SURFACE RESORPTION
LEAST DESTRUCTIVE
TYPE OF RESORPTION
MAIN CAUSE IS TRAUMA
NOT SEEN
RADIOGRAPHICALLY
CAN BE SEEN ONLY
HISTOLOGICALLY
NOTREATMENT
TRANSIENT
OR
PROGRESSIVE

44. B ) EXTERNAL INFLAMMATORY RESORPTION
MOST COMMON &
DESTRUCTIVE
ETIOLOGY :
1)Injury orirritation of
periodontal tissues
2)Trauma leading to pulp
necrosis
3)Excess orthodontic
forces
4)Trauma fromocclusion
5)Pressure
resorption(cyst,tumors)
RADIOGRAPHIC
FEATURES :
Bowl like radiolucency with
ragged irregularareas seen
along with loss of tooth
structure & bone

45. CAUSE -
•caries extending to the pulp
• traumatic intrusive luxation,
oravulsion with re-
implantation resulting in
necrosis of the root canal
systemand development of
periapical periodontitis/cyst
RADIOGRAPHIC CHANGES :
•PDL space widens and loss of
the surrounding lamina dura
occurs.
•The apical root surface becomes
irregularand ragged at eitherthe
mesial ordistal surfaces .
•As the apical periodontitis
becomes more progressive, the
apical root resorption becomes
extensive, causing shortening of
the apical one third of the
involved root

46. CAUSES :
•bacteria fromperiodontal
disease
• periodontal treatment
• trauma
•intracoronal bleaching
• orthodontics
• bruxism
RADIOGRAPHICALLY :
moth-eaten, irregular
radiolucency superimposed
overa root canal in the
cervical one third with
extension to the surface or
PDL space

47. C ) APICAL REPLACEMENT RESORPTION/DENTOALVEOLAR ANKYLOSIS
RADIOGRAPHIC
APPEARANCE :
•Moth eaten
appearance with
irregularborder
•Absence of
periodontal ligament
space & lamina dura
CAUSE :
Occurs as a result
of complications
following avulsion
in which
periodontal
ligament dries &
loses its vitality
SERIOUS
CONDITION-teeth
becomes a part of the
bone

48. INTERNAL
RESORPTION
A) ROOT CANAL REPLACEMENT / METAPLASTIC RESORPTION
RADIOGRAPHIC
FEATURES :
Enlarged canal space
Resorption of dentine followed
by deposition of hard tissue that
resembles bone orcementum
CAUSE :
Low grade irritation of pulpal
tissue

49. B) INTERNAL INFLAMMATORY RESORPTION
RADIOGRAPHIC
FEATURES :
Round orovoid
radiolucent area
in the central
portion of the
tooth –
BALLOONING
AREA
Progressive loss of dentine
is present without
deposition of hard tissue in
the resorption cavity
CAUSES :
1)Longstanding injury
causing c/c pulp
inflammation &
circulatory changes
2)Sudden trauma leading
to intrapulpal
haemorrage-clot-
granulation tissue-
odontoclast-resorption

50. PULPAL LESIONS
PULPAL SCLEROSIS PULPAL OBLITERATION PULP STONES

51. PERIAPICAL LESIONS

52. PERIAPICAL
GRANULOMA
PERIAPICAL CYST/
RADICULAR CYST
PERIAPICAL
ABSCESS
RADIOLUCENT LESIONS

53. APICAL PERIODONTITIS
Localized inflammation of
periodontal ligament in the apical
region
Main feature-tooth is tender on
percussion
RADIOGRAPGICALLY – thickening
of pdl space
Preceeded by SAP or an apical
abscess
No subjective signs & symptoms
RADIOGRAPHICALLY –
“smoldering” lesion-periradicular
bone resorption
SYMPTOMATIC APICAL PERIODONTITIS ASYMPTOMATIC APICAL PERIODONTITIS

54. • Mental foramen may be directly
superimposed over apex of mandibular
premolars
• Shadows may be shifted far to mesial or
distal merely by shifting horizontal
angle of cone of the x-ray machine
• Nasopalatine foramen may be superimposed on
apex of maxillary central incisors.
• if radiolucent area in the radiograph is actually a
lesion truly associated with tooth periapex, its
shadow will remain “attached” to root end

55. CONDENSING OSTEITIS/
CHRONIC FOCAL
SCLEROSING
OSTEOMYELITIS
SCLEROTIC BONE/
IDIOPATHIC PERIAPICAL
OSTEOSCLEROSIS
HYPERCEMENTOSIS
RADIOPAQUE LESIONS

56. INTERPRETATION OF RESTORATIONS & DENTAL MATERIALS
AMALGAM
RESTORATIONS
ONE SURFACE
AMALGAM
RESTORATIONS
AMALGAM OVERHANGS AMALGAM FRAGMENTS

57. GOLD RESTORATIONS
GOLD FOIL RESTORATIONS GOLD CROWNS AND BRIDGES

58. STAINLESS STEEL
CROWNS

59. CAST METAL
POST
FIBRE POST
PREFABRICAT
ED TITANIUM
POST

60. PORCELAIN
RESTORATIONS
ALL – PORCELAIN CROWNS
PORCELAIN FUSED TO METAL
CROWNS

61. COMPOSITE
RESTORATIONS
ACRYLIC
RESTORATIONS

62. BASE MATERIALS
ZINC PHOSPHATE(Cemento LS) > CONVENTIONAL GLASS IONOMER(KetacBond) > RESIN MODIFIED
GIC(Fugi II LC) > RESIN CEMENT(Rely X ARC) > ENAMEL
Radiodensity of base, liner and luting dental materials Clin Oral Invest DOI 10.1007/s00784-005-0030-3

63. GUTTA PERCHA SILVER POINTS

64. INTERPRETATION OF ROOT CANAL ANATOMY
FAST BREAK
Sudden change in radiolucency within a canal; this change in
density probably signals the beginning of an additional canal
(Slowey)
Slowey RR. Radiographic aids in the detection of extra root canals. Oral Surg 1974;37:762-72

65. WALTON’s PROJECTION
Simple technique
Anatomy of superimposed structures,root & pulp
chambers may be well defined
TECHNIQUE :
1. vary the horizontal angulation of the central beam (overlapping
canals maybe separated)
2. The apply Clark’s rule (SLOB) or Ingle’s MBD rule to identify the
canals

66. TARGET OR BULL’s–EYE PHENOMENON OR
SCORPION TOOTH

67. DENS INVAGINATUS / DENS IN DENTE
A developmental anomaly resulting in a deepening orinvagination
of the enamel organ into the dental papilla priorto calcification of
dental tissues
RADIOGRAPHICA
LLY – tooth within
a tooth appearance

68. OTHER DEVELOPMENTAL ANOMALIES
GEMINATION : Attempt at division of a single tooth
germ by an invagination with resultant incomplete
formation of two teeth
FUSION : Occurs through union of two
normally separated tooth germs
CONCRESCENCE : form of fusion
which occurs after root formation is
complete.here teeth are united by
cementum only

69. TAURODONTISM : condition whereby the body of the tooth and pulp chamber
is enlarged vertically at the expense of the roots. As a result, the floor of the
pulp and the furcation of the tooth is moved apically down the root.
AMELOGENESIS IMPERFECTA : rare abnormal formation of
the enamel. due to the malfunction of the proteins in the
enamel : ameloblastin , enamelin, tuftelin and amelogenin.
RADIOGRAPHICALLY – SQUARE shaped crowns with thin layer of
enamel
DENTINOGENESIS IMPERFECTA : genetic disorder of tooth development.
This condition is a type of dentin dysplasia that causes teeth to be discolored
(most often a blue-gray or yellow-brown color) and translucent giving teeth an
opalescent sheen. Teeth are also weaker than normal, making them prone to
rapid wear, breakage, and loss. These problems can affect both primary
(deciduous) teeth and permanent teeth
RADIOGRAPHICALLY-constricted cervical portion.SHELL TEETH & pulpal
obliteration

71. REFERENCES
Dental radiology, Principles & Techniques – Joen M Iannucci, Laura Howerton
Oral Radiology,7th
edition – Stuart C White , Michael Pharoah
Textbook of dental & maxillofacial radiology – R. Karjodkar
Endodontics – Ingle
Endodontics-principles & practices- Mahamoud Torabinejad, Richard Walton
Shafer’s textbook of oral pathology,6th
edition – R.Rajendran
Dental Trauma Guide – International association of Dental traumatology
Digital Radiography As A Diagnostic Tool In Dentistry-American association of dental
maxillofacial radiographic technicians
Dental Root Resorption: A Review of the Literature – Compendium - April 2011, Volume 32,
Issue 3