Download Radiographs in Endodontics

Radiographs in Endodontics
 Normal
radiographic anatomy
 Interpretation
 Application
 Importance of endodontic
radiography
 Specialized radiographic
techniques
Normal radiographic
anatomy

Radiographic recognition of the
disease requires Sound knowledge of
the radiographic appearance of
normal structures
Teeth
Cervical burn out
Diffuse radiolucent
areas
 Mesial & distal -cervical regions
 Between the edge
of the enamel cap &
crest of alveolar
ridge.

Supporting structures
Lamina Dura
Tooth socket -- thin
radiopaque layer of
dense bone
 X-ray beam passes
tangentially through
many times the
thickness of thin
wall


Thickness and density–the amount of
occlusal stresses

LD--- wider and more dense(heavy
occlusion)

LD--- thin and less dense (not subjected to
occlusal function)

Intact LD indicates vital pulp
Alveolar crest

Gingival margin of
the alveolar
process that
extends between
the teeth ---radiopaque line

Not more than
1.5mm from CEJ of
adjacent teeth
Periodontal ligament
space

Radiolucent space
between tooth root
and LD
Varies in width—
-patient to patient,
- tooth to tooth,
-location to
location around
one tooth.

Maxilla
Intermaxillary suture (median suture)

Thin radiolucent line in the midline between
two portions of premaxilla

Extends from alveolar crest between
central incisors

Continues posteriorly between the
maxillary palatine processes to the
posterior aspect of hard palate
Anterior nasal spine
Periapical radiographs
of max CI
 Midline,radiopaque
 About 1.5 to 2 cm
from the alveolar
crest
 Below the junction of
the inferior end of
nasal septum and
inferior outline of
nasal fossa

Nasal fossa

Lies just above the
oral cavity

Radiolucent
Incisive foramen

Nasopalatine or
anterior palatine
foramen

Lies in the midline
of the palate
behind the central
incisor

Between the roots
of CI
Lateral fossa(incisive fossa)
-- Gentle depression in the maxilla near
the apex of LI
–Appear diffusely radiolucent
Nasolacrimal canal

Formed by nasal
and maxillary bones

Seen on maxillary
occlusal projections
in the region of
molars
Maxillary sinus
 Air containing cavity lined with mucous
membrane

Three sided pyramid

Base--medial wall adjacent to the
nasal cavity

Apex extending laterally into zygomatic
process of maxilla
Three sides are;
Superior wall
forming the floor
of the orbit
2. Anterior wall
extending above
premolars
3. Post wall above
the molar teeth
and max
tuberosity
1.

Roots of molars usually lie in close
apposition to max sinus

Borders of max sinus appears as thin ,
delicate radiopaque line
Zygomatic process

Extension of lateral max surface that
arises in the region of the apices of first
and second molars
on periapical
radiographs–

U shaped
radiopaque line
 Open end directed
superiorly
 Enclosed rounded
end is projected in
the apical region of
first and second
molar
Pterygoid plate

lies immediately posteriorly to
tuberosity of maxilla

radiopaque
Mandible
Symphysis
Infantsradiolucent line
through the midline
of the jaw between
the images of the
forming deciduous
CI
 Suture fuses by the
end of first year of
life

Genialtubercles
(mental spine)
 Lingual surface of
the mand
 Spine shaped
 Well visualized in
mand occlusal
radiographs
 Periapical--radiopaque mass in
the midline below
Incisor roots
Mental ridge

Periapical
radiographs of
Mand CI--seen as 2
radiopaque lines
sweeping bilaterally
forward and
upward toward the
midline
Mental fossa

Radiolucent
depression on the
labial aspect of
mandible between
the alveolar ridge &
the mental ridge
Mental foramen


Anterior limit of inferior dental canal
Round, oblong, slit-like or irregular
Half way between lower border of mand
and crest of alveolar process,
(region of the apex of second premolar)

When mental foramen is projected over
one of the premolar apices it may stimulate
periapical disease
( continuity of lamina dura around the apex—
indicates absence of periapical
abnormality)

Mandibular canal

Dark linear shadow
with thin radiopaque
superior and inferior
borders cast by
lamella of bone that
bounds the canal

Located jus inferior
to apices of
posterior teeth
Application

Diagnosis of hard tissue alterations

Number,location,size,shape and direction
of roots and root canals

Localize hard to find or disclose
unsuspected,pulp canals
 Locate a pulp ---receded or calcified

Position of structures in F-L dimension

Position and adaptation of primary filling
point

Evaluate -- final root canal filling

Examination of lips,cheeks and tongue for
fractured tooth fragments & foreign
bodies

Hard-to-find apex ---periradicular surgery

Confirm foll periradicular surgery and
before suturing ==tooth fragments and
filling materials have been removed

Follow up films ==outcome of treatment
Viewing conditions





Ambient light in viewing room should be
reduced
Mounted in a film holder
Size of the view box should accommodate
the size of the film
Intense light source -- to evaluate dark
regions of the film
Magnifying glass --detailed information of
small regions of the film
Interpretation
Wuehrmann
 review one structure at a time--- -- lamina
dura
 Follow this structure all the way around
the first tooth on the left and then around
the next tooth and the next until the full
film or full mouth survey is scanned
 Findings --normal or changed.


Proceed to next structure ---crowns of
teeth

Each crown is evaluated independently

Radiographic coronal evaluation includes
depth of caries and restoration with
respect to pulp

Crest of alveolar process should then be
followed
--from left to right
--upper to lower
--structures outside the alveolar process
should be evaluated - sinuses ,floor of
nose,foramina and so

Tracing the dark periodontal ligament
space will reveal number, size and shape
of the roots
While observing the root
-periradicular lesions
-root defects --anomalies,fractures and
external resorption


Number,size shape,curvature of all the
canals

Internal resoption, pulp stones, linear
calcification and open apices

Anatomic structures can be mistaken for
pulpoperiradicular lesions

Expoure at Different angulation and by
pulp testing

Radiolucencies not associated with the root
apex --projected away from the apex by
varying the angulation
Importance of
Endodontic Radiography


Radiograph-- paramount importance
Excellent diagnostic films
=before treatment
=during treatment
= after treatment
INITIAL RADIOGRAPHS

Studied carefully

Not only as an aid in diagnosis but also a
“blue print” for what to expect during
treatment

Identifying presence and nature of
pathosis

Size and shape of pulp chamber

Direction and angulation of the canals as
they leave the pulp chamber

Obstructions -pulp stones

Curvature of roots and approximate length
of tooth

Distal or mesial inclination of the roots
CONFIRMATORY RADIOGRAPHS

Second most valuable film

after initial entry into crown ,access
opening appears to be headed away from
the canal orifice ---evaluate alignment
Confirmatory length- of- tooth film

Position of the file tip in relation to root
apex

Shows whether the file is in the canal as
intended or has entered a root perforation
Confirmatory trial point radiograph
 Confirms the visual and tugback
judgement of the fit of initial filling point

Provides the final opportunity to judge the
advancement of instrumentation

Confirmatory post- treatment film

Determines the length, density,
configuration and quality of obturation

Should be made before a coronal
restoration is placed

Imp during surgery-- searching for root
tips, lost filling material, location of root
apexes during trephination or apicoectomy

Post- treatment evaluation
radiograph

Evaluate the changes taking place
periradicularly

Abnormal or unusual findings -----retreat either surgically or non surgically
Re-treatment radiography

Before initiating re-treatment--fresh film

Tooth , perforations, broken instruments,
failure to obturate, ineffective surgery.
RADIOGARPHS FOR TRACING

Supplemental radiographs --chronic
draining sinus

A GP cone (30 size) is placed into the
tract with cotton forceps until solid stop
is felt

Periodontal lesions may also be traced
radiographically --depth and extent

A silver point of size 30 is placed into the
tract until it is stopped by the sulcus depth
or bone and is then radiographed
Helps to

Determine the depth of pocket

Amount of supporting bone on a periodontally
involved tooth

Which root of a multirooted teeth-amputated or treated with periodontal
surgery

Buccal object rule-cone or tube
shift technique, clarks rule or SLOB
rule

visualize the anatomy of superimposed
structures, roots, pulp canals

vary the horizontal angulation of central
ray of x-ray beam

Clarks rule states that -- the most distant
object from the cone (lingual) moves
toward the direction of the cone
Radiographic diagnosisperiradicular lesions

Pulpal inflammation and necrosis -periradicular changes

Widening of PDL space usually at the apex

Apical external resorption

Apex --slightly blunted to gradually
resorbed

It may also be obliquely resorbed or
have a cupped out appearance

chewed appearance of the tree felled
by a beaver

Moth eaten appearance -- tooth by
accident was rippled loose from its
ligament and /or was replanted
Condensing osteitis

Exact opposite of root resorption

Teeth with chronic pulpal infl

Root is blunted by inflammatory
resorption and then this space is filled by
osteosclerotic bone

radiopaque appearance on X-ray films

Foll successful RCT radiopacity slowly
changes back to normal appearance
Asymptomatic apical periodontitis

Well circumscribed osseous lesion

Radiographically-Thickening of PDL and
resorption of lamina dura to destruction of
apical bone



Size varies from few mm to cm or larger in
size
Do not always appear on the periapex.
Occasionally they are seen on the lateral
surfaces of the root associated with
lateral canal
Asymptomatic apical abscess

Larger, more diffuse and irregular
radiolucent lesion

Lesion may drain into mouth thru a sinus
tract or extraorally onto to the neck or
chin
Apical cyst

Lesion appear more circumscribed

Move roots of the teeth laterally-PATHOGNOMONIC feature of cyst
Lesions of non endodontic origin

Pathologic changes may be mistaken for
periradicular lesions of pulpal origin

Non odontogenic cyst-globulomaxillary
cyst, the midline palatal cyst and cyst of
nasopalatine canal

cysts are not associated with the exact
root end ---move away from the root ends -horizontal angulation is varied

To be further considered in D/D of cystsvitality of pulp

Apical cyst-Non vital

Non odontogenic cysts --traumatic injuries
causes pulp death

Periodontal lesion may be mistaken
for periradicular lesion of endodontic
origin

Periodontal probe and pulp testerinvaluable method

Place a silver or GP point in periodontal
probe and take a radiograph

If the lesion is traceable to the apex of the
tooth and pulp responds to pulp testing-10
periodontal involvement
Specialized
radiographic
techniques
Direct digital radiography

Direct replacement of an X-ray film
with an electron image receptor or
sensor and an image is displayed on
the computer
DDR makes use of a

Solid state sensor, typically a CCD,

Complimentary metal oxide silicone or a
charge injection device connected by a
cable to a computer, a monitor and a
printer

DDR sensor is packaged in a hard aluminium
or plastic shell

X-ray --is converted by a screen to green
light transmitted through an optical fiber
to CCD sensor

CCD then converts green light to electrons
that are deposited in electron wells for
subsequent read out ,line by line by the
electronics
Advantage

Instantaneous availability of images after
exposure without removing sensor from the
mouth

Allows multiple angles to be taken
--location of canals
--identification of root curvatures
--verification of working length
--verification of obturation
.
Tangible benefits

No dark room or processing equipment is
needed

Infection control procedures are reduced

Duplicates are instantly made with absolute
no loss in image quality

Sensitivity of the receptors and digital
nature of the image
X- ray exposure

Computers ===store and enhance the image

Radiographic picture on the computer
screen ====treatment
Time savings
Time is saved by not waiting for film
processing
 Retakes
-ease of retakes
-instant
-X-ray head ,patient and sensor are still in
place

Dose
reduction
-- low X-ray dosage
Tooth length measurement
Begin at the apex and advance the cursor
toward the crown with the mouse
 computer --calculate a preoperative length
in mm even around curvatures

Sensor size

small sensor size -comfortable for
the pt,and easier
for the assistance
to place

larger sensors -more difficult to
place(rigidity)
Digital subtraction radiography

Uses a computer to assess, in two or more
radiographs, pathologic changes that have
taken place over a period of time

2 digital images to be compared are
brought into computer software

Stored in a numeric format in the
computer memory

compared mathematically

Background images have not changed
(crowns , fillings etc)--are subtracted
which inturn highlights area that have
changed (lesion size)
Tomography

it is a radiographic technique that
essentially slices the teeth into thin
sections

computers then reassemble the sections
to generate a three dimensional image
Pulp spaces and roots
 B-L curvature,
 Shape of the canal space and location of
the apical foramen

An additional adv–
-- elimination of specialized angled
radiography
-- All angled views will be simultaneously
captured in one exposure

Thank You