RADIOGRAPHIC INTERPRETATIONS IN

ENDODONTIC DIAGNOSIS

Liya Alice Thomas

CONTENTSIntroduction

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

INTRODUCTION

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.

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

APPLICATION OF RADIOGRAPHY IN ENDODONTICS

1. 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

LIMITATIONS OF RADIOGRAPHS

1. 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

TYPES OF IMAGING TECHNIQUES

CONVENTIONAL SPECIALIZED

1. Intraoral periapical radiograph

2. Bitewing radiographs3. Occlusal radiographs

1. Tomography a)Conventional b)Computed c)Three dimensional2. Scanography3. Stereoscopy4. Magnetic resonance imaging5. Digital subtraction radiography6. Digital radiography7. Xeroradiography8. CBCT

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

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

OCCLUSAL RADIOGRAPHS

designed to provide a more extensive view of the maxilla and mandible.

USES : 1.determining the buccolingual extension of pathologic conditions2.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

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 fractures3.Evaluation of dental implants

4.In diseases of the TMJ

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 tumors2)Assessment of TMJ

3)Detecting salivary gland pathosis4)Preoperative assessment of

alveolar bone height & thickness before placing implants

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

surgery2)Evaluation of maxillofacial

tumors 3)Proper implant design &

placement

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

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.

Journal of conservative dentistry Year : 2014 Volume : 17 Issue : 3 Page : 225-229

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

STEREOGRAPHY

Requires the exposure of two films one for each eye as the tube is shifted to 10% of focal

film distanceThen they are viewed with

stereoscope that uses either mirrors or prisms to coordinate

the accommodation

USES :1.Evaluation of bony pockets in periodontal diseases2.TMJ evaluation3.Status of dental implants4.Root configurations

Stereographic assessment vs.clinical assessment of mandibular canal in relation to the roots of impacted lower third 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 85–89

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

lesions2. Tumor staging in salivary

glands,pharynx & larynx3. Investigations of TMJ

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 enhancement2.High contast3.Positive & negative displays

• USES :1. Determine height of alveolar

ridge2. Detection of caries3. endodontics

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

RVG :-

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 of carious lesions

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.

INTERPRETATION OF DENTAL CARIESCariosus (LATIN) - rottenness

CLASSIFICATION OF CARIES ON DENTAL RADIOGRAPHS

INTERPROXIMAL CARIES

INCIPIENT INTERPROXIMAL CARIES

MODERATE INTERPROXIMAL CARIES

ADVANCED INTERPROXIMAL CARIES

SEVERE INTERPROXIMAL CARIES

OCCLUSAL CARIES

INCIPIENT CARIES MODERATE CARIES SEVERE CARIES

BUCCAL & LINGUAL CARIES

ROOT SURFACE CARIES

CERVICAL BURNOUT

Root configuration

Shape of cemento-enamel junction

Exposure factors

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

RECURRENT CARIES

RAMPANT CARIES

INTERPRETATION OF TRAUMA, PULPAL AND PERIAPICAL LESIONS

FRACTURES

CROWN FRACTURES

TRAUMA

Enamel fractureEnamel-dentin

fractureEnamel-dentin-pulp

fracture

Crown-root fracture without pulpal involvement

Crown-root fracture with pulpal involvement

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

ALVEOLAR FRACTURE

LUXATION

INTRUSIVE LUXATION EXTRUSIVE LUXATION SUBLUXATION

AVULSION CONCUSSION

RESORPTION

PHYSIOLOGIC PATHOLOGIC

INTERNAL EXTERNAL

Root canal replacement

Internal inflammatory

External surface resorption

External inflammatory

Apical replacement

PHYSIOLOGIC RESORPTION

PATHOLOGIC RESORPTION

EXTERNAL RESORPTION

A ) EXTERNAL SURFACE RESORPTION

LEAST DESTRUCTIVE TYPE OF RESORPTION

MAIN CAUSE IS TRAUMA

NOT SEEN RADIOGRAPHICALLYCAN BE SEEN ONLY HISTOLOGICALLY

NO TREATMENT

TRANSIENTOR

PROGRESSIVE

B ) EXTERNAL INFLAMMATORY RESORPTION

MOST COMMON & DESTRUCTIVE

ETIOLOGY :1)Injury or irritation

of periodontal tissues

2)Trauma leading to pulp necrosis

3)Excess orthodontic forces

4)Trauma from occlusion

5)Pressure resorption(cyst,tumo

rs)

RADIOGRAPHIC FEATURES :

Bowl like radiolucency with ragged irregular areas seen along with loss of tooth structure

& bone

CAUSE -•caries extending to

the pulp• traumatic intrusive luxation, or avulsion with re-implantation

resulting in necrosis of the root canal system and development of

periapical periodontitis/cyst

RADIOGRAPHIC CHANGES :

•PDL space widens and loss of the surrounding

lamina dura occurs.•The apical root surface becomes irregular and ragged at either the

mesial or distal 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

CAUSES :•bacteria from periodontal disease• periodontal treatment• trauma •intracoronal bleaching• orthodontics• bruxism

RADIOGRAPHICALLY :moth-eaten, irregular

radiolucency superimposed over a

root canal in the cervical one third with

extension to the surface or PDL space

C ) APICAL REPLACEMENT RESORPTION/DENTOALVEOLAR ANKYLOSIS

RADIOGRAPHIC APPEARANCE :

•Moth eaten appearance with irregular border

•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

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 or

cementum

CAUSE :Low grade irritation of

pulpal tissue

B) INTERNAL INFLAMMATORY RESORPTION

RADIOGRAPHIC FEATURES :

Round or ovoid

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 changes2)Sudden trauma

leading to intrapulpal

haemorrage-clot-granulation tissue-

odontoclast-resorption

PULPAL LESIONS

PULPAL SCLEROSIS PULPAL OBLITERATION PULP STONES

PERIAPICAL LESIONS

PERIAPICAL GRANULOMA

PERIAPICAL CYST/ RADICULAR CYST

PERIAPICAL ABSCESS

RADIOLUCENT LESIONS

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

• 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

CONDENSING OSTEITIS/ CHRONIC FOCAL

SCLEROSING OSTEOMYELITIS

SCLEROTIC BONE/ IDIOPATHIC PERIAPICAL

OSTEOSCLEROSISHYPERCEMENTOSIS

RADIOPAQUE LESIONS

INTERPRETATION OF RESTORATIONS & DENTAL MATERIALS

AMALGAM RESTORATIONS

ONE SURFACE AMALGAM

RESTORATIONSAMALGAM OVERHANGS AMALGAM FRAGMENTS

GOLD RESTORATIONS

GOLD FOIL RESTORATIONS GOLD CROWNS AND BRIDGES

STAINLESS STEEL CROWNS

CAST METAL POST

FIBRE POST

PREFABRICATED TITANIUM

POST

PORCELAIN RESTORATIONS

ALL – PORCELAIN CROWNSPORCELAIN FUSED TO METAL

CROWNS

COMPOSITE RESTORATIONS

ACRYLIC RESTORATIONS

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

GUTTA PERCHA SILVER POINTS

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

WALTON’s PROJECTION

Simple techniqueAnatomy 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

TARGET OR BULL’s–EYE PHENOMENON OR SCORPION TOOTH

DENS INVAGINATUS / DENS IN DENTE

A developmental anomaly resulting in a deepening or invagination of the enamel organ into the dental

papilla prior to calcification of dental tissues

RADIOGRAPHICALLY – tooth

within a tooth appearance

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

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 teethRADIOGRAPHICALLY-constricted cervical portion.SHELL TEETH & pulpal obliteration

REFERENCESDental 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