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RADIOLOGYIN

ENDODONTICs

Presented ByJean Michael

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History

• 1895 – Discovery of cathode rays by Roentgen• 1895 – Dr. Otto Walkoff took the 1st dental X ray (of his own teeth)• 1899 – Dr. Edmund Kells used Radiographs to determine the root length during RCT• 1900 – Dr. Weston Price advocated the use of radiographs to check the adequacy of

root canal fillings

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How To Obtain A Good Radiograph

1. Proper placement of film in the patient’s mouth

2. Correct Angulation of the cone in relation to the film and oral structures

3. Correct exposure time4. Proper developing technique

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Relevant Findings For An Endodontist

• Presence of Caries that may involve or threaten to involve the Pulp

• Number, course, shape and length of root canals

• Calcification or obliteration of pulp cavity• Internal and External Resorption• Thickening of Periodontal Ligament• Nature and extend of Periapical and Alveolar

Bone Destruction

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• Diagnose abnormalities like Dilaceration and Taurodontism

• Diagnose fracture of root • To estimate and confirm the length of root

canals before instrumentation (working length determination)

• To confirm the position and adaptation of master cone

• Evaluation of outcome of root canal therapy (post operative radiograph)

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Types of Radiographs

• Intraoral Radiographs– Intraoral Periapical (IOPA)–Occlusal Radiographs–Bitewing Radiographs

• Extraoral Radiographs–Panoramic Radiographs– Lateral Cephalograms

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Intraoral Periapical Radiographs

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Occlusal Radiographs

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Bitewing Radiographs

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Panoramic Radiograph

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Lateral Cephalogram

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Disadvantages of Radiographs

• Radiographs are 2D shadow of a 3D Object• They are only suggestive and not the final

evidence in judging a clinical problem• Bucco-lingual dimension cannot be assessed in

an IOPA• The bacterial status of the hard and soft tissues

cannot be determined • Chronic inflammatory tissues cannot be

differentiated from healed fibrous scar tissue

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• Lesions of the medullary bone are undetected in the radiographs till there is substantial bone loss and the involvement of cortical bone

• For a hard tissue lesion to be evident on a radiograph, there should be at least a mineral loss of 6.6 %

• Even a single error in the procedure can render a radiograph useless

• Over exposure to X rays are harmful to the body and strict precautions are to be maintained for the patient and the operator

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Techniques Employed for IOPA

• Paralleling Technique

• Bisecting Angle Technique

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ParallelingTechnique• Film is placed parallel

to the long axis of the tooth to be radiographed

• The film is exposed using X rays which are perpendicular to its surface

• Requires special film holding devices

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Film Holding Devices

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Bisecting Angle Technique

• The X rays pass perpendicular to the angular bisector of the angle formed by the long axis of the tooth and the X ray film

• No film holding devices are required

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Normal Anatomical Landmarks

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Enamel, Dentin & Pulp

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Cervical Burnout

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Radical Pulp & Apical Foramen

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Radical Pulp

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Lamina Dura

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Lamina Dura (extracted tooth)

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Double Periodontal Ligament and Lamina Dura

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Periodontal Ligament Space

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Periodontal Ligament Space

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Intermaxillary Suture

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Incisive Foramen

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Soft Tissue Shadow of the Nose

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Nasolacrimal Duct

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Inferior Border of Maxillary Sinus

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Neurovascular Canals in the Walls of Maxillary Sinus

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Zygomtic Process of Maxilla

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Shadow of Nasolabial Fold

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Genial Tubercles

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Lingual Foramen

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Mental Foramen

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Mental Foramen

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Mandibular Canal

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Mandibular Canal

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Nutrient Canals

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Nutrient Canals

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Mylohyoid Ridge

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Mylohyoid Ridge

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Coronoid Process of Mandible

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IOPA Radiographs in Endodontic Therapy

• Diagnostic Radiographs

• Working Radiographs

• Post operative Radiographs

• Follow up Radiographs

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Diagnostic Radiographs

• Ideally, these radiographs should be taken using paralleling angle technique

• They should be of high quality without any foreshortening or elongination

• They help for proper diagnosis of the case• These radiographs helps in determining the

prognosis by comparison with post operative and follow up radiographs

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Comparison between Diagnostic and Follow up Radiographs

Periapical Cyst Before RCT Complete Bony repair after RCT

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Working Radiographs• These radiographs are used for determining

the position of instruments – files etc during the procedure

• These radiographs are to be taken without removing the rubber dam as it can cause contamination of the operating field

• Bisecting angle technique can be used• A better alternative is the use of a hemostat as

a film holding device

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Radiograph showing Endodontic Instruments & Rubber Dam Clamp

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Working Radiograph with Master Cone

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Working Radiographs of same tooth using Different Angulations

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Advantages of using a Hemostat

• Film placement is easier when the opening is restricted by the Rubber dam and frame

• In the mandibular posterior area, the closing of mouth relaxes the mylohyoid muscle permitting the film to be placed farther apically

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• The handle of the hemostat is a guide to align the cone in a proper vertical and horizontal angulation

• There is less risk of distortion caused by finger pressure and film displacement as in bisecting angle technique

• Any movement can be detected by the shift of the handle and corrected before the exposure

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Using a Hemostat as a Film Holder

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Film is Perpendicular to X Ray Beam

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View From Above

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Mesial Angulation of X ray Beam

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Distal Angulation of X ray Beam

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Rubber Dam – Is It Necessary ?

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Postoperative Radiographs

• They are used to evaluate the endodontic treatment

• They are taken after removing the rubber dam• Ideally paralleling angle technique should be

used • They can be compared with the diagnostic

radiograph

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Post Operative Radiograph

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Overdenture Abutment

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Overextension into Inferior Alveolar Canal leading to Permanent Paresthesia

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Follow-up Radiographs

• These radiographs are taken to evaluate the prognosis of the endodontically treated tooth

• After obturation, the tooth may have to undergo procedures like core build up, crown fabrication etc

• The follow up radiograph gives the health of the periodontium and the tooth by evaluating the presence of root resorption, other treatment failures etc

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Before Bleaching 2 Years After Bleaching

External Root Resorption

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Follow up Radiographs After RCT

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Recovery from Furcal Bone Loss after RCT

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Endo – Perio Lesion

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Vertical Angulation

• Elongation – Corrected by increasing the vertical angle of the central ray

• Foreshortening – Corrected by decreasing the vertical angle of the central ray

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Horizontal AngulationClarke’s Rule (S.L.O.B Rule)

• The object that moves in the SAME direction as the cone is located toward the LINGUAL

• The object that moves in the OPPOSITE direction as the cone is located toward the BUCCAL

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Central Ray Perpendicular to the Film

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Central Ray directed 20˚ Mesial to film

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Working Radiographs with Instruments inside the Root Canals

Superimposition of Files 4 separate Files in root canals

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X-ray Beam passing through Two Thicknesses of Root Structure

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X-ray Beam aimed 20˚ Mesially through Single Thicknesses of Hourglass Root

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Radiographic Diagnosis Of Pathologic Conditions

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Caries Involving the Pulp

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Pulp Calcification following Avulsion

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Internal Resorption following Trauma

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Internal Resorption

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Internal Resorption following Trauma

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Extensive Internal Resorption

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External Resorption following Trauma

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Fracture of Crown Exposing the Pulp

Crown Fracture After 3 Years

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Fracture of Crown involving Pulp

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Root Fracture at Multiple Sites

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Fracture Healed by Interproximal Bone

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Extensive Wear of Mandibular Incisors

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Luxation

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Apical Condensing Osteitis

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Apical Condensing Osteitis associated with Chronic Pulpitis

Just after RCT 1 Year after Treatment

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Enostosis (Sclerotic Bone)

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Tooth Intruded due to Trauma

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Circumferential Dentigerous Cyst

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Periradicular Cemental Dysplasia

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Radicular Lingual Groove

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Dens Invaginatus with Radicular Lesion

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Hereditary Hypophosphatemia

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Digital Radiography

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• The digital systems relies on an electronic detection of an X ray generated image that is electronically processed and reproduced on a computer screen

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Advantages

• Reduced exposure to radiation• Increased speed of obtaining the image• Possibility for digital enhancement• Storage as digital data in computers• Ease of transmissibility• Elimination of manual processing steps

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Intraoral X ray Sensors

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Digital Image Enhancement

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Inversion

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Contrast

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Measurement of Angle of Root Curvature

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Flash Light

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Magnification

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Pseudocolour

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Linear Measurement

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Conclusion

• Radiograph is a very powerful tool for a dentist, especially an Endodontist with which he are able to examine the status of hard tissue which are beyond the field of his naked eyes

• Application of radiology gives new standards for the diagnosis, treatment and prognosis of a dental problem

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REFERENCE

• Grossman’s Endodontic Practice 12th edition• Endodontics 6th edition – Ingle• Oral Radiology 6th edition – White & Pharoah

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THANK YOU