Use of the EPT & the Apex

Question 1

– Sensibility
(2)

Answer 1

• Does the tooth respond to a stimulus
• Example: Hot, Cold, EPT

Question 2

– Vitality
(2)

Answer 2

• Does the tooth have pulpal blood flow
• Example: Laser Doppler Flow, Pulse Oximetery

Question 3

– Specificity

Answer 3

• Ability of a test to identify people WITHOUT disease

Question 4

– Sensitivity

Answer 4

• Ability of a test to identify people WITH disease

Question 5

Do we use EPT as part of routine
clinical testing?

Answer 5

no

Question 6

Do we use EPT as part of routine
clinical testing?
NO!
(2)

Answer 6

• EPT is NOT a
  primary or routine
  clinical testing
  instrument.
• Thermal testing is
  inconclusive, use the
  EPT.

Question 7

EPT is an ADJUNCT to
thermal sensitivity testing.
(2)

Answer 7

– 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.

Question 8

– (2) used in conjunction resulted in a
more accurate method for diagnostic testing.

Answer 8

Cold test and EPT

Question 9

– If tests positive to EPT and cold, –% chance it is
vital.

Answer 9

97

Question 10

– If tests negative (=80) to EPT and cold, –% chance
it is necrotic.

Answer 10

90

Question 11

Electric Pulp Tester

Answer 11

• Deliver current
  sufficient to stimulate
  A-delta fibers

Question 12

EPT
– If sharp sensation felt,

– If no sensation felt,

Answer 12

some functioning
nerve fibers are
present in the pulp

fibers not functioning

Question 13

EPT reveals
response of fibers
as current increases
on a scale from

Answer 13

0-
80.

Question 14

Is a tooth with a reading of 20 more or less
vital than a tooth with a reading of 40 or 60?

Answer 14

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.

Question 15

Simple Rule:
Reading < 80:
Reading = 80:

Answer 15

Tooth likely “vital” (intact nerve fibers
present)
Tooth likely necrotic (intact nerve fibers
not present)

Question 16

EPT
How to Use
(7)

Answer 16

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)

Question 17

CONDUCTOR?
(3)

Answer 17

• Toothpaste
• Electrode Gel
• Water

Question 18

WHERE?
* Anteriors:
* Premolars:
* Molars:

Answer 18

Facial surface or incisal edge
Buccal cusp tip
Mesiobuccal cusp tip

Question 19

False Positives
(7)

Answer 19

– 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

Question 20

False Negatives
(7)

Answer 20

– 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

Question 21

Unreliable with …
* Trauma
(2)

Answer 21

– Loss of normal response for period of time
– 1-3 months

Question 22

Unreliable with …
* Immature Pulp
(3)

Answer 22

– May yield no response (80)
– Fewer A-delta fibers
– Nerves have not reached maximal depth of
penetration

Question 23

Length Determination
Methods?
(3)

Answer 23

• Electronic apex locator
• Radiographic determination
• Paper point
• Feel

Question 24

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

Answer 24

electrical components
Dentin and cementum
fluids
1 mm

Question 25

In the Canal * Apex locator will display bars as you approach the --- * Intermittent “---” * No --- lines

Answer 25

apex Beep red

Question 26

What we want to see (3)

Answer 26

* Apex locator will display a red bar * Constant “Beeeeeeeeep” * Red line = patency

Question 27

What does the apex locator tell us? (3)

Answer 27

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

Question 28

What do the numbers 3, 2, and 1 on the apex locator mean?

Answer 28

Nothing The numbers indicate you are within the canal, not the distance from the apex

Question 29

ELA How to Use

Answer 29

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

Question 30

WL Radiograph * Use a #15 file (3)

Answer 30

– 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)

Question 31

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

Answer 31

PDL PDL RED

Question 32

Root Canals Not Suitable for EAL (5)

Answer 32

Exceptionally large apical foramen Fluid overflowing orifice Broken crown w/ gingival intrusion Small access with metallic restoration Caries touching gingiva