Electric pulp testing is a technique used to assess the health of dental pulp. It works by applying a gradating electric current to the tooth to stimulate pulp nerves. If the patient feels sensation, it indicates pulp vitality. However, electric pulp testing has limitations as a response does not necessarily mean healthy pulp, and lack of response does not always mean non-vital pulp. Factors like thickness of enamel, distance of electrode from pulp, and extent of restoration can influence results. While useful, electric pulp testing must be interpreted along with other diagnostic methods and clinical findings.

1. ELECTRIC PULP TESTING
DR DITHYKUMARI K K

2. Introduction
• The ideal pulp test method should provide a simple, objective, standardized,
reproducible, nonpainful, non injurious, accurate and inexpensive way of
assessing the condition of the pulp tissue (chambers 1982). These tests are
also defined as sensibility tests, as they assess whether there is response to a
stimulus
• The use of electricity as an aid in the diagnosis of pulp diseases is older than
the use of radiography in dentistry (reynolds 1966).

3. Electric pulp tester
It is an instrument that uses gradations of electric
current to excite a response from susceptible
elements of the pulpal tissues.

4. Key uses of pulptesting in clinical practice
Prior to operative procedures
Diagnosis of pain
Investigation of radiolucent areas
Post-trauma assessment
Assessment of anaesthesia
Assessment of teeth which have been pulp capped
or required deep restoration

5. Types of EPTs
Two modes of EPTs exist, monopolar (or unipolar)
and bipolar, with each being divided into two
categories: those with a mains power connection and
those that work with batteries (Ehrmann
1977, Närhi et al. 1979).

7. The mid-1950s, most EPTS were bipolar and some had double electrodes that had to
contact the tooth. The electrical current flowed from one electrode to the other through
the tooth, and if the patient felt pain or a tingling sensation then the tooth was considered
to have pulp tissue. However, this method was extremely unreliable (cohen &
hargreaves 2006). In another method, one electrode was applied to the tooth, whilst the
other was held in the hand of the patient (ingle & bakland 2002, cohen & hargreaves
2006). Nowadays, most epts are monopolar with the anode often placed on the lip and
the cathode on the tooth. When the electrode is applied to the tooth surface, the circuit is
completed through the body of the patient via the lip clip.

8. In this situation, it is essential for the dentist to touch the patient with the opposite hand not
holding the EPT. To ensure a suitable contact, the hand should preferably be moistened; it is
possible for the practitioner to feel the current passage through his/her own hands
(matthews et al. 1974a,

9. Monopolar stimulation will excite periodontal nerves at a level of stimulus below threshold
for some pulp nerves, but they cannot be excited with bipolar stimulation even when
intensities 15 times greater than the highest threshold of the pulp nerves are applied
(Greenwood et al. 1972). When bipolar stimulation is used, the current flows from the
cathode to the anode, but the current path is confined to the coronal part of the tooth
(Mumford 1957), which probably explains why the periodontal nerve fibres are not
stimulated.

10. Objective
 to stimulate intact A delta nerves in the pulp–dentine complex by applying
 an electric current on the tooth surface. A positive result stems from an
ionic shift in the dentinal fluid within the tubules
 causing local depolarization and subsequent generation of an action
potential from intact A delta nerves.

11. Mechanism of action
It functions by producing a pulsating electrical stimulus, the initial intensity of which should
be at a very low value to prevent excessive stimulation and discomfort. The intensity of the
electric stimulus is then increased steadily at a pre-selected rate, and a note is made of

12. EPT is technique sensitive and must be performed carefully removal of supragingival calculus may be required,
particularly in mandibular incisors, to gain complete access to the cervical area of the tooth.
After that, the exterior surface of the tooth should be dried; ideally, the teeth should be isolated with a rubber
dam although in practice this is rarely performed (Ingle & Bakland 2002).
If the teeth contain any proximal metallic restorations, these must be insulated from each other by inserting
celluloid strips or pieces of rubber dam through their contact point as a high electrical potential is used, the
current may be conducted to an adjacent tooth or it may flow along wet tooth surfaces to the gingival tissue to
give false positive responses

13. The utmost desired area of valuation in incisor teeth is at the incisal edge, where the enamel is thinnest or
absent.
The pulp tester should be placed on the tooth surface nearby to a pulp horn, as this obtains the highest nerve
concreteness with in the pulp.
This site parallels to the incisal third region of anterior teeth and the mid-third region of posterior teeth.
The threshold for reaction may be influenced by the chunkiness of the enamel and dentine covering the pulp
The response threshold for healthy teeth may be lowest in incisors, some what greater in premolars, and
greatest in molar teeth. have shown that the optimum site for electrode placement on molars was on the tip
of the mesiobuccal cusp.

14. Procedure

15. Commonly used electrolytes are Nichollas-colloidal graphite, Grossman toothpaste.
To have fast response, electrode should be applied at the area of high neural density like incisal one third of
anterior teeth (it’s close to pulp horns) and middle third of posterior teeth
• Precaution should be taken to avoid it contacting adjacent gingival tissue or metallic restorations to avoid
false-positive response.
• Confirm the complete circuit from electrode throught he tooth to the body of the patient and then back to
• the electrode. If gloves are not used, the circuit gets completed when clinician’s finger contact with electrode
• and patient’s cheeks. But with gloved hands, it can be done by placing patient’s finger on metal electrode
handle or by clipping a ground attachment on to thepatient’s lip

16. An electric pulp tester tip and contact medium placed on
sound tooth structure.

17. If a full coverage restoration is present, a
bridging technique can be utilized. A fine tip
of an explorer or file can be used to contact
tooth structure cervical to the crown margin,
and the EPT probe tip contacts the instrument
.
The bridging technique demonstrating an explorer tip contacting the tooth and
the electric pulp tester tip contacting the explorer

18. A lip electrode is placed over the patient's lip.
If the pulp is vital the patient describes feeling a sensation which is variously described as
tingling, vibration, pain, shock.
Before testing the tooth in question, it is important to educate and acclimatize the patient to
the sensation first on a control tooth.
more user-friendly method is to ask the patient to hold the lip electrode. The plastic cable is
held in one hand and the metal electrode between the forefinger and thumb of the other hand
as shown in Figure 4.21c. This method allows the patient to have control by releasing their
finger grip on the metal electrode when they feel the defined (not any) sensation; thus
reducing the element of an anxiety-driven response

19. Testing the reliability of the responses can also be achieved using the
EPT with the current switched off or by changing the sequence of the
teeth being tested to prevent the results from being affected by the
patient’s reaction because of his/her bias and/or anxiety

20. (i)The pulp is deemed normal when there is a response
to the stimulus provided by the sensibility test and this
response is not pronounced or exaggerated, and it
does not linger
(ii)Pulpitis is present when there is an exaggerated
response that produces pain. Pulpitis can be
considered as reversible or irreversible, depending on
the severity of pain and whether the pain lingers or not.
Typically mild pain of short duration is considered to
indicate reversible pulpitis while severe pain that
lingers indicates irreversible pulpitis
iii)The absence of responses to sensibility tests is
usually associated with the likelihood of pulp necrosis,
the tooth is pulpless, or has had previous root canal
therapy

21. Ideal Situations for Electric Pulp Testing
• testing on anterior teeth has a high degree of reliability because these teeth are single
rooted, are easy to isolate.
• Excellent evaluation of teeth involved in traumatic accident.
• The electric pulp test may be an important aid in determining when a problem is
caused by pulpal or by periodontal damage
• The death of a single pulp may produce a radiolucency that involves the apices of
adjacent teeth and suggest endodontic therapy for multiple members of the arch

22. factors that influence EPT result for false
positive or false negative response
• the thickness of enamel and dentine,
• concentration of pulpal neural elements,
• direction of dentinal tubules,
• amount of dentinal fluid
• the distance between the electrode tip and the pulp.

23. Potential Deficiencies of Pulp Testers.
the output of current on a given reading may vary from time to time, or even from tooth to tooth.
Large restorations or bases may prevent the current from reaching dentinal tubules attached to processes extending to the pulp.
Molars may give readings not indicative of the true pulpal condition because some combination of vital and nonvital canals may be present.
If the canal in proximity to the tooth electrode is vital, a relatively normal
reading will be recorded even if the other canals are necrotic.
reactivity of the nerves to electrical stimulation is not synonymous with normalcy
The nerve tissue, being highly resistant to inflammation, might remain reactive long after the surrounding tissues
have degenerated
.

24. Potential Deficiencies of PulpTesters.
False-positive response in
Teeth with acute alveolar abscess because gaseous or liquefied products within the
pulp canal can transmit electric current.
Electrode may contact gingival tissue, thus giving the false-positive response
In multirooted teeth, root canals and necrosed in others pulp may be vital in one or
more canals
reactivity of the nerves to electrical stimulation is not
synonymous with normalcy. The nerve tissue, being highly resistant to
inflammation, might remain reactive long after the surrounding tissues have
degenerated.
False-negative response in
Recently traumatized tooth
Recently erupted teeth with immature apex
Patients with high pain threshold
Calcified canals
Poor battery or electrical deficiency in plug in pulp testers
Teeth with extensive restorations or pulp protecting bases
under restorations
Patients premedicated with analgesics or tranquilizers, etc.
Partial necrosis of pulp sometimes is indicated as totally
necrosis by electric pulp tester

25. Teeth involved in splints or bridges may test positive to electric current by virtue of
transferring the stimulus to adjacent vital abutments for a reaction
temporary stopping may be placed around the pontics or abutments adjacent to the test
tooth to prevent any transference
• older" teeth, despite the patient's age, may be similarly unresponsive. mean teeth in
which deep erosion or abrasion has produced heavy areas of sclerotic dentin.

26. Considerations/limitations regarding use of EPT
• A response to an EPT does not provide any information about the health status of the pulp, its
circulation, or its integrity.
• The EPT is not reliable for testing immature teeth because the myelinated fibres entering the
pulp may not reach their maximum number until 5 years after tooth eruption or until they
have been in function for 4–5 years.
• EPTs for teeth which have full or partial coverage with a metallic restoration can create
difficulty because of the limited access to tooth structure for tip placement and the large size of
many electrode tips.

27. SENSITIVITY
• It is the ability of a test to correctly classify an individual as diseased.
• Probability of being test positive when the disease is present.

28. SPECIFICITY
• It is the ability of a test to correctly classify an individual as disease free.
• Probability of being test negative when disease is absent.

29. Evaluation of threshold response and appropriate electrode
placement site for electric pulp testing in fluorosed anterior
teeth
• The hyper mineralized enamel in fluorosed teeth may influence the fluid
concentration in the dentinal tubules, which is thought to play a vital role in the
conduction of electric impulses.
• In fluorosed enamel, hydroxyapatite crystals are substituted by fluorapatite
crystals
• fluorosed teeth showed high threshold response when compared to
nonfluorosed teeth, possible reasons may be hypermineralized enamel, which
might influence the fluid concentration in the dentinal tubules, which is thought
to play a vital role in the conduction which may result in ionic shift in the
dentinal fluid

30. Diagnostic Accuracy of 5 Dental Pulp Tests:
A Systematic Review and Meta-analysis
• his study is the first systematic review that provides the quantitative analysis of the diagnostic accuracy of 3 pulp sensibility
tests and 2 pulp vitality tests.
• Laser Doppler flowmetry and pulp oximetry were the most accurate diagnostic methods based on their high accuracy (97%).
Electric pulp testing was less likely to correctly identify nonvital teeth but more likely to correctly identify vital teeth based on
its low sensitivity (72%) and high specificity (93
%).
• Cold pulp testing showed generally high diagnostic accuracy values among pulp sensibility tests.

32. • Three types of responses.
The pulp is deemed normal when there is a response to the stimulus provided by the
sensibility test and this response is not pronounced or exaggerated, and it does not
linger
Pulpitis is present when there is an exaggerated response that produces pain. Pulpitis
can be considered as reversible or irreversible, depending on the severity of pain and
whether the pain lingers or not. Typically mild pain of short duration is considered to
indicate reversible pulpitis while severe pain that lingers indicates irreversible pulpitis
The absence of responses to sensibility tests is usually associated with the likelihood
of pulp necrosis, the tooth is pulpless, or has had previous root canal therapy

33. Conclusions
• Electric pulp tests can be a valuable aid to the process when assessing the state of the
dental pulp, although cold pulp sensibility tests are usually more reliable, more useful and much easier
to perform.
• However, in some cases thermal tests are not reliable, and so an EPT should also be used, such as in
teeth with pulp canal calcification, when equivocal results are obtained with thermal tests and when
following up traumatized teeth.
• While EPT is a valuable test in general and specialist endodontic practice, no single
technique can reliably interpret and diagnose all pulpal conditions
• .

34. REFERENCES
• Gopikrishna V, Pradeep G, Venkateshbabu N. Assessment of pulp vitality: a
review. International journal of paediatric dentistry. 2009 Jan;19(1):3-15.
• Chen E, Abbott PV. Dental pulp testing: a review. International journal of
dentistry. 2009 Oct;2009
• . Vemisetty H, Vanapatla A, Ravichandra PV, Reddy SJ, Punna R,
Chandragiri S. Evaluation of threshold response and appropriate electrode
placement site for electric pulp testing in fluorosed anterior teeth: An in vivo
study. Dental Research Journal. 2016 May;13(3):245.