Use of the EPT & the Apex Flashcards
– Sensibility
(2)
- Does the tooth respond to a stimulus
- Example: Hot, Cold, EPT
– Vitality
(2)
- Does the tooth have pulpal blood flow
- Example: Laser Doppler Flow, Pulse Oximetery
– Specificity
- Ability of a test to identify people WITHOUT disease
– Sensitivity
- Ability of a test to identify people WITH disease
Do we use EPT as part of routine
clinical testing?
no
Do we use EPT as part of routine
clinical testing?
NO!
(2)
- EPT is NOT a
primary or routine
clinical testing
instrument. - Thermal testing is
inconclusive, use the
EPT.
EPT is an ADJUNCT to
thermal sensitivity testing.
(2)
– If we do not get a definitive
or reproducible result with
thermal testing, incorporate
EPT.
– If thermal testing provides
a result in accordance with
clinical signs and
symptoms, do not
incorporate EPT.
– (2) used in conjunction resulted in a
more accurate method for diagnostic testing.
Cold test and EPT
– If tests positive to EPT and cold, –% chance it is
vital.
97
– If tests negative (=80) to EPT and cold, –% chance
it is necrotic.
90
Electric Pulp Tester
- Deliver current
sufficient to stimulate
A-delta fibers
EPT
– If sharp sensation felt,
– If no sensation felt,
some functioning
nerve fibers are
present in the pulp
fibers not functioning
EPT reveals
response of fibers
as current increases
on a scale from
0-
80.
Is a tooth with a reading of 20 more or less
vital than a tooth with a reading of 40 or 60?
Neither!!!
* Do not attempt to differentiate “vitality” based on
the magnitude of the numbers (20 vs. 40 vs. 60)
* EPT does not give an accurate indication of the
histological health or disease state of the pulp.
Simple Rule:
Reading < 80:
Reading = 80:
Tooth likely “vital” (intact nerve fibers
present)
Tooth likely necrotic (intact nerve fibers
not present)
EPT
How to Use
(7)
Dry the tooth
Isolate tooth with cotton roll
Place conductor on tooth
Patient and Dentist hold wand
Patient releases when sensation felt
Record number
Start with healthy teeth
(Test 2-3 to establish baseline)
CONDUCTOR?
(3)
- Toothpaste
- Electrode Gel
- Water
WHERE?
* Anteriors:
* Premolars:
* Molars:
Facial surface or incisal edge
Buccal cusp tip
Mesiobuccal cusp tip
False Positives
(7)
– Poor isolation
– Conductor in contact with adjacent teeth
– Touched gingiva
– Patient comprehension
– Patient anxiety
– Conduction via interproximal restorations
– Putrescence of pulp tissue communicating with
adjacent teeth
False Negatives
(7)
– Failed to achieve adequate contact with tooth
– Patient finger does not achieve adequate contact
– High pain threshold
– Battery low
– Machine not working
– Sedative medication
– Orthodontic activation
Unreliable with …
* Trauma
(2)
– Loss of normal response for period of time
– 1-3 months
Unreliable with …
* Immature Pulp
(3)
– May yield no response (80)
– Fewer A-delta fibers
– Nerves have not reached maximal depth of
penetration
Length Determination
Methods?
(3)
- Electronic apex locator
- Radiographic determination
- Paper point
- Feel
Electronic apex locator
Basic Principles
* Human tissues have characteristics that
can be modelled by a combination of…
* (2) are insulators
* At apex, conductive — are present
* Apical constriction approximately —
short of root tip
electrical components
Dentin and cementum
fluids
1 mm
In the Canal
* Apex locator
will display bars
as you
approach the —
* Intermittent
“—”
* No — lines
apex
Beep
red
What we want to see
(3)
- Apex locator
will display a
red bar - Constant
“Beeeeeeeeep” - Red line =
patency
What does the apex locator tell us?
(3)
We are in the canal (blue)
We are at the PDL (red)
We use this measurement to determine our working length. Subtract 1 mm
from RED length to establish working length
What do the numbers 3, 2, and 1
on the apex locator mean?
Nothing
The numbers indicate you are within
the canal, not the distance from the
apex
ELA
How to Use
Educate patient on procedure
and expectationsAssemble, turn on, and check
battery meter (70% or >)
Assemble, turn on, and check
battery meter (70% or >)Connect lip clip and file holder
(Fig 1.)
*If continuous beep present, apex locator
is working
Connect lip clip and file holder
(Fig 1.)
*If continuous beep present, apex locator
is workingPlace lip clip on corner of mouth
(Fig 2.)
*Do not remove rubber dam
Place lip clip on corner of mouth
(Fig 2.)
*Do not remove rubber dam
Insert Size 10 file into canalClip file holder to file
(Fig 3)
Clip file holder to file
(Fig 3)Slowly negotiate canal to
get controlled swing of bars
* Proceed until 1st solid tone
Slowly negotiate canal to
get controlled swing of bars
* Proceed until 1st solid toneMove rubber stopper to
reference point or note
reference mark on file
Move rubber stopper to
reference point or note
reference mark on fil
Remove clip and fileMeasure file length
from rubber stopper
Measure file length
from rubber stopperSubtract 1 mm to
establish WL
Subtract 1 mm to
establish WLRepeat for all canals
Repeat for all canals
WL Radiograph
* Use a #15 file
(3)
– Able to identify tip
on radiograph
– Ensure placed 1
mm short of
patency length
– Do not spend more
than 5 minutes
(call for faculty if
not working)
Detecting Perforations
“Procedural Misadventure”
* Perforations happen
* Early detection and repair,
better long-term prognosis
* Apex locator identifies when
we have reached —
* Perforation is direct
communication with —
* Apex locator immediately
goes to — upon entrance
to perforation
PDL
PDL
RED
Root Canals Not Suitable for EAL
(5)
Exceptionally large apical
foramen
Fluid overflowing orifice
Broken crown w/ gingival
intrusion
Small access with metallic
restoration
Caries touching gingiva
