Dental Pulp status
DEPT OF PEDODONTICS AND
– DIAGNOSTIC OBJECTIVES
– PULP VITALITY TESTS
– THERMAL TESTING
– ELECTRICAL TEST
– SPECIAL TESTS
– BITE TEST
– STAINING AND TRANSILLUMINATION
– SELECTIVE ANAESTHESIA
– TEST CAVITY
– LASER DOPPLER FLOW METRY
– PULSE OXIMETRY
– NEWER TECHNIQUES
– DISEASES OF PULP
Dental pulp tests are investigations that provide valuable
diagnostics and rx planning information to the dental
clinician. If pathosis is present, pulp testing combined
with information taken from the history, examination and
other investigations such as radiographs leads to
diagnosis of underlying disease which can be used
From the late 1970’s until 90’s, application of pulp tests
in different areas of clinical dentistry were met with
varying degree of success. This could be interpreted
that, to date the notion of ideal diagnostic test is still to
be realized. From a technical prespective, all current
Pulpal tests have shortcomings interms of accuracy,
reliability and reproducibility in a given diagnostic
challenge. In addition the correct application of pulp test
in the appropirate clinical situations.
Diagnostic objective of pulp testing
As an investigation , pulp testing can have several aims
1. Assessment of pulp health based on qualitative
This is commonly done:
-prior to restorative , endodontic, and orthodontic
-as a follow up and monitoring the pulp after trauma to
-in differential diagnosis such as excluding periapical
pathosis of pulp origin.
• The most accurate way of evaluating the pulp status is by
examination of histological sections of the tissue specimen
involved to assess the extend of inflammation or presence
of necrosis as a mean of gauging pulp health. Unfortunately
in the clinical scenario. These are both impractical and not
feasible;hence clinicians must use investigations such as
pulp tests to provide additional diagnostic information.
PULP VITALITY TESTING, PULP SENSIBILTY TESTING
AND PULP SENSTIVITY
Pulp vitality testing- Assessment of pulp’s blood supply
Pulp tissue may have an adequate vascular supply, but
is not necessarily innervated. Hence, most of the
current pulp testing modalities do not directly assess
the pulp vascularity. Examlpe is tooth with fresh
trauma can have no response to cold for a period of
time stimulus following injury., newly errupted tooth,
• PULP SENSIBILITY TEST: Assessment of the pulp
• Sensibility test is defined as a ability to respond to
stimulus, and hence this is a accurate and appropriate
term for typical and common clinical pulp tests such as
thermal and electrical tests given that they do not
detect or measure the blood supply of the dental pulp.
• PULP SENSITIVITY: Condition of pulp being very
responsive to a stimulus.
• Thermal and electrical pulp tests are not sensitivity
tests though they can be used as sensitivity tests
when attempting diagnosis a tooth with pulpitis since
such teeth are more responsive than others
Pulp testing techniques and
Thermal Pulp Test
•Various methods and materials have been used to test the pulp ‘s
response to thermal stimuli.
•The baseline or normal response to either hot or cold is a patient’s report
that a sensation is felt but disappear immediately upon removal of the
thermal stimulus .
•Heat testing is most useful when a patients complaint is intense dental
pain upon contact with any hot liquid or food.in instances where a
patients is unable to identify which tooth is sensitive ,a heat test is
•Starting with the most posterior tooth in that area of the mouth , each
tooth is individually isolated with the rubber dam.
•An irrigating syringe is filled with a liquid that has a temperature similar
to that which would cause the painful sensation.42 C
•The liquid is then express from the syringe onto the isolated tooth to
determine whether the response is normal or abnormal.
•The tooth will exhibit an immediate , intense painful responds to the
Heat with the heat testing a delayed response may occur ,so waiting 1o
seconds between each heat test will allow sufficient for any onset or
symptoms ,another method for heat testing is applied heated gutta –
purcha or compound stick to the surface of the tooth.
•If this method is used, a light layer of lubricant should be placed onto the
tooth surface prior to applying the heated material to prevent the hot
gutta purcha 78 C TO 150 C By ZACH ET AL or compound from adhering
to the dry tooth surface.
•Cold is the primary pulp testing method for many practitioners today.
•Cold testing should be used in conjunction with the electric pulp tester so
that results from one test will verify the findings of the other test.
• It can be accomplished similarly to heat testing by individually
teeth with a rubber dam.Dachi n associate recommended use of ¼” ice cone
Placed against the tooth for 5 sec to quantify cold test.
-Max of 15 sec can be used for detection of pulpal vitality
•Another benefit of this technique for cold testing is that it requires no
armamentarium except for a rubber dam.
•If a clinician choose to perform this test with sticks of ice , then the
use of the rubber dam is recommended because melting ice will run
onto adjacent teeth and gingiva, yielding potentially false positive
•Frozen carbon dioxide (co2)also known as dry ice or carbon dioxide
snow, has been found to very reliable in eliciting a positive response if
vital pulp tissue is present in the tooth by EHRMANN. Carbon dioxide
has also been found to be effective in evaluating the pulp response in
teeth with full coverage crowns for which electric pulp testing is not
possible. In contrast, Fulling and Andreasen61 found that thermal
testing with carbon dioxide snow gave consistently positive responses
irrespective of the stage of dental development.
•For testing purposes a solid stick of co2 gas into a specially design
Is believed that cold testing cause contraction of dentinal
fluids, this results in outward flow of fluids with in patent
tubules. This rapid flow results in hydrodynamic forces
acting on A delta fibers in dentino pulpal complex leading
to sharp sensation for few seconds in sound tooth.
• Refrigeant Spray , dichlor-difluoromethane-DDM, O C
• Ethyl chloride- -41 C
• Carbon-dioxide snow -72 C
• Recently ozone free non fluorocarbons sprays
• TETRA FLUORO ETHANE- 30 C
•The resulting co2 is stick is applied to the facial surface of either natural
tooth structure or crown.several tooth can be tested with single stick.
•The tooth should be isolated with a 2*2gauze or cotton.so co2 will not
come into contact with these structures.
•The most popular method of testing is with a refrigerant spray.
•It is readily available and easy to use,and provides test result that are
reproducible, reliable and equivalent to that co2 .(ODONTOTEST)
•The current product contain 1,1,1,2-tetrafluroethane,which has zero
ozone depletion potential and is environmentally safe.
•It has temperature -26.2c .
•The spray is most effective or testing purpose when it is applied to the
tooth on large #2 cotton pellete.
•The sprayed cotton pellete should be applied to the midfacial of the Crown.
•The sensitivity which is the ability of a test to identify teeth that are
diseased , was 0.83 for cold and 0.86 for heat and 0.72 for the electric test.
•This means the cold test correctly identified 83% of the teeth that had
A necrotic pulp while heat test where correct 86% of the time and
electric pulp test were correct only 72% of the time.
REFRIGERATOR SPRAY CONTAINER
A COTTON ROLL CAN BE USED TO FORM A LARGE COTTON PELLET
Electric Pulp Test
•Assessment of the pulp vitality test is most frequently accomplished
by electric pulp testing or cold testing.
•The vitality of the pulp is determined by the intactness and health of the
the vascular supply, not the status of the pulpal nerve fibres.
•Even though advances are being made with regard to determine the
vitality of the pulp regard to the blood supply, this technology is not
accurate enough to be used on a routine basis in clinical setting
•The electric pulp tester has limitations in providing information about the pulp.
ELECTRI PULP TESTER WITH PROBE
•The response of the pulp to electric testing is not reflecting the histologic
health status of the pulp.
•A response by the pulp to the electric current only denotes that some
viable nerve fibres are present in the pulp and are capable of responding.
•The lack of response has been found most frequently when an electric
pulp is present.
•The electric pulp tester will not work unless the probe can be placed in
contact with the natural tooth.
•With the advent of universal precautions for infection control, the patient
may be required to place a finger on the tester probe to complete the
electric circuit for the models, however lip clips are an alternative to
having patients hold the tester.
•The use of rubber gloves prevents the clinician from completing the
•proper use of the electric pulp tester requires that the tooth to be
evaluated be isolated and dried.
•A control tooth of similar tooth type and location in the arch should be
tested first in order to establish a base line response and to inform the
patients with a normal sensations.
•The suspected tooth should be tested at least twice to confirm the results.
•The tip of the testing probe that will be placed in contact with the tooth
structure must be coated with the electric conducting based media.
• The most commonly used media is toothpaste.
•The coated probe tip is placed in the incisal third of buccal or facial area
of the tooth to be tested.
•once the probe is contact with the tooth the patient is asked to touch the
•This completes the circuit and initiates the delivery of electric current to
•The patient is instructed to remove his or her finger from the probe when
a tingling or warming sensation is felt in the tooth.
•The readings from the pulp tester are recorded and will be evaluated once
all the appropriate teeth have been tested and the result obtained from
other pulp testing methods..
•The tip of the endodontic explorer is coated with tooth paste or other
appropriate media and placed in contact with the natural tooth.
•The tip of the electric pulp tester probe is coated with a small amount of
tooth paste and placed in contact with the side of the explorer.
•However, unlike electric pulp testing, cold testing can reveal the health
and integrity of pulp tissue response.
•Until such time that testing method used to assess the vascular supply of
the pulp become less time consuming and technique sensitive to thermal
and electric pulp testing will continue to be the primary methods for
determining pulp vitality.
PULP NERVE TESTER
•Identifying cracked tooth or fractured cusp.
•It also helpful in diagnosing cases where in pulpal pathosis is
extended to periradicular region causing apical periodontitis
•Tooth slooth & Frac Finder are available devices for bite test
•Pain on biting -- apical periodontitis
•Pain on release of bite force - cracked tooth
To determine which tooth is sensitive to mastication and which part of the tooth is
sensitive,having the patients bite on a specialy designed bite stick often helpful.
•For the bite test to be meaningful a device should be used that will
allow practitioners to apply pressure to individual cusp or areas of tooth.
•Variety of devices have been used for the bite test including cotton
applicators , tooth picks, orange wood sticks, rubber polishing
• As with all the pulp test, adjacent teeth should be use as controls
so that the patient is aware of the normal response to these test.
•The small cupped out areas on the instruments is placed in contact
with the cusp to be tested.
•The patient is then asked to apply biting pressure with opposing
teeth to the flat surface on the opposing side of the device.
•The biting pressure should be applied slowly until full closure is
•The firm pressure should be applied for few seconds, the patient is
then asked to release the pressure quickly.
•Each individual pressure on a tooth can be tested in a like manner.
•The practitioner should note if the pain is elicited during the
pressure phase or upon quick release of pressure.
•A common finding is with fractured cusp or cracked tooth is
frequent presence pain upon release of biting pressure.
Staining and transillumination
•In order to determine the presence of crack in the surface of the
tooth, the application of a stain to the area is often of great
•Shining a bright light on the surface of the tooth is also very
•When symptoms are non localized or refered, the diagnosed may be
•Sometimes the patients may not even able to specify whether the
symptoms are emanating from the maxillary or mandibular arch.
•This test is restricted to the patient who are in pain at the
time of the test when the usual tests have failed to identify
•The objective is to anesthetize one tooth at a time until the pain.
disappears and is localized to a specific tooth
•Using either infiltration or intraligament injection, inject the
most posterior tooth in the area suspected of being the cause
•If the pain persist anesthetize the next tooth mesial to it and
continue to do so until the pain disappears
•If the pain cannot be identified as from maxillary or
mandibular origin ,an inferior alveolar block is given
•Cessation of pain naturally indicates involvement of mandibular tooth
•This test is obviously a last resort and has an advantage over
the ‘test cavity’ during which iatrogenic damage is possible
•This method is used only when all other test methods are deamed
impossible or the result of the other test are inconclusive .
•This test allows one to determine the pulp vitality
•It is performed when other methods of diagnosis have failed
•The test cavity is made by drilling through the enamel-dentin
junction of an un-anesthetized tooth
•The drilling should be done at slow speed and without a
•Sensitivity or the pain felt by the patient is an indication of
•No endodontic treatment is indicated
•Sedative cement is then placed in the cavity ,search for
source of pain continues
•If no pain is felt -cavity preparation may be continued until
the pulp chamber is reached ,If pulp is completely necrotic-
endodontic treatment can be continued.
Problems with current devices/assessing pulp status
At present the techniques that are commonly used in everyday practice
(i.e. thermal and electric pulp testing) assess whether the nerve supply
within the tooth is intact. A positive result conﬁrms that the Ad nerves in
this region of the pulp chamber are responsive; the inference is that
this can be interpreted as there being an intact blood supply within the
tooth. However, the only true means of assessing the health of the pulp
is to determine that there is a normal ﬂow of blood within the tooth
.Thermal tests are highly subjective as they are wholly dependent on
the patient’s response to testing. There is no accurate or objective
method of assessing how responsive the tooth under investigation is to
testing, nor of comparing with a previous measurement. In contrast,
electric pulp testers have numerical digital displays, which allow the
operator to note down the reading, and compare with a previous
False responses from pulp testing
Contact with metal restorations
Vital tissue still present in partially necrotic
root canal system
Incomplete root development
Recently traumatized teeth
Recent orthodontic activation
Patients with psychotic disorders
Ideal features of a pulp vitality tester
-Assesses pulp blood ﬂow
-Free from error
-Effective for heavily restored teeth
-Effective when the pulp size is
-Quick and easy to use
RECENT PULP VITALITY ASSESSMEMT
Crown surface temperature/heat registration
The evaluation of tooth-surface temperature as a means of assessing the vitality
of teeth has been reported. Cholesteric liquid crystals, which exhibit different
colors when heated, have been used in one study to determine pulp vitality . It
was based on the principle that teeth with an intact pulp blood supply (vital/healthy
pulp status) had a warmer tooth-surface temperature compared with teeth that
had no blood supply.
Surface temperature of teeth has been measured over a period of time at 15-s
intervals using an electric thermometer attached to a surface probe, which was
placed in contact with the tooth .These studies showed that after teeth were
cooled, there was only a rise in the temperature of vital teeth.
The detection of blood ﬂow within the pulp by passing light through the tooth has been
reported . Hemoglobin absorbs certain wavelengths of light, while the remaining light
passes through the tooth and is detected by a receptor. Photoplethysmography has
been compared with LDF in experiments on skin, and found to be of similar value . The
technique has not been successfully developed further for dental application apart
from one recent investigation .
LDF 1st in dentistry by GAZELIUS ET AL IN 1986
LDF is a non-invasive method of assessing and measuring the blood ﬂow of pulp tissue.
Laser light wavelengths 633 and 780 nm is directed onto the tooth under investigation
by securing a ﬁber-optic probe against the tooth surface. The laser light from the probe
passes along the enamel prisms to the enamel–dentine junction and theS-shaped
dentinal tubules, which act as light guides, to the pulp .Light absorbed by red blood cells
in the capillary plexus is scattered and undergoes a shift in frequency according to the
Doppler principle; light absorbed by stationary objects does not undergo a shift in
frequency. A signal is produced which measures the ﬂux of the blood cells (number of
red blood cells times mean velocity). The proportion of Doppler-shifted light is detected
by a photodetector. The detected signal is weak and there- fore highly ampliﬁed; a
mathematical calculation using Fourier analysis can be used to gain more meaningful
information. A trace of signals from vital and non- vital teeth. Fourier analysis of the
traces has revealed a heart beat frequency in the vital tooth, but not in the non-vital tooth
and is therefore an effective discriminator.
•.This technique is accurate ,reliable and reproducible method of
assessing pulpal blood flow.
• Even with this positive findings ,the technology is not advanced
enough for this method to be used on a routine basis in a dental
• If technology can be developed whereby the testing with the LDF
can be accomplished in minutes ,it will likely replace the thermal
and electric pulp testing methods
A LDF probe showing laser light
A LDF probe applied to a sectioned
showing the passage of light via the
enamel prisms and
dentinal tubules to the pulp.
A LDF trace showing signals from two teeth; the
upper is from a vital tooth while the lower is from a non-
A study by MIWA ETAL suggested that the transmitted light technique can
Detect pulpal blood flow in young permanent teeth and is thus applicable assess
•Another non-invasive method[4,5] that has been investigated as a method to
determine pulpal blood flow uses a pulse oximeter ,which is designed to
measure the oxygen concentration of the blood and the pulse rate.
•It works on the principle that two wavelengths 660 nm and 940 nm.of light
transmitted by a he ne source and photoelectric diode detect oxygenated and
deoxygenated haemoglobin as they pass through a body part to a receptor.
•The diffrences between the light emitted and the light received is
calculated by a microprocessor to provide the pulse rate and oxygen
concentrations in the blood.
•Attempts to use the pulse oximeter to diagnose pulp vitality have met
mixed results .
•The device used for pulp testing are too cumbersome and complicated to
be used on a basis in a dental practice.
Meanism of dental pulp oximeter: (a).light emitting diode emitting red light at 660nm.(b).light – emitting diode
emitting infra red light at .940nm.(c)photo etector.(d)pulse oximeter monitor.(e)pulse oximeter sensor.(f).custom made
pulse oximeter sensor holder.HbO2 ,oxygenated haemoglobin.HbR,deoxygenated haemoglobin ;SpO2, oxygen saturation
of arterial blood.
-Use dual wavelength light in an effort to asertain the content of
closed chamber like pulp, has been tested with optimist.
Only initial experimental results r obtained.
TRANSMITTED LASER LIGHT
-Experimental variation of LDF, aimed to eliminate non pulpal
signals. No better results were found.
-Utilize strong light source which identifies color changes that may
indicate pulp changes. Not useful in posterior teeth n teeth with
restorations. Use as an adjunct to conventional technique.
ULTRAVIOLET LIGHT PHOTOGRAPHY
-Examine different fluorescence pattern allows additional contrast
of otherwise difficult to observe in visible light. This also an
adjunct to conventional tests.
VARIOUS CONDITIONS AND PULPAL RESPONSE TO TESTS
Reversible pulpitis / Pulpal hyperemia
•Reversible pulpitis[2,4] is a mild to moderate inflammatory condition of
the pulp caused by the noxious stimuli in which the pulp caused by
capable of returning to the uninflamed state following removal of the
•Symptomatic reversible pulpitis is characterised by sharp pain lasting for a
moment,and generally disappears when the stimulus is removed
•Cold , sweet, or sour usually causes it
•Pain may become chronic.
•The pulp may recover completely or the pain may last longer each time
and intervals of relief may become shorter ,until the pulp finally succumbs
•The pulp is sensitive to temperature changes, particularly cold, application
of cold is an excellent method of locating and diagnosing the involved
•A tooth with reversible pulpitis reacts normally to percussion, palpation
•Thermal test are useful in locating the affected tooth if unknown.
•The electric pulp test, using less current than on a control tooth, is an
excellent corroborating test.
•Irreversible pulpitis[2,4] is a persistant inflammatory condition of the pulp,
symptomatic or asymptomatic caused by a noxious stimulus.
•A tooth with symptomatic irreversible pulpitis exhibit intermittent or
spontaneous pain, whereby rapid exposure to dramatic temperature
changes (especially to cold stimuli) will elicit heightened and prolong
episodes of pain even after the source of the pain is removed.
•The pain may be sharp or dull localised or referred.
•In the early stages the thermal test may elicit pain that persists after
removal of the thermal stimulus.
•In the late stages when the pulp is exposed ,it may respond normally to
the thermal stimulus.
•The electric pulp test induces a response with a marked variation in
current form of normal.
•Result of examination for mobility and perussion and palpation tests are
Chronic Hyperplasic Pulpitis
•Chronic hyperplastic pulpitis[2,4] or ”pulp polyp” is a productive pulpal
inflammation due to an extensive carious of a young pulp
•Slow , progressive carious exposure of the pulp is the cause.
•Mechanical irritation from chewing and bacterial infection often provide the
•The tooth may respond feebly or not at all to the thermal test, unless one use
extreme cold, as from an methyl chloride spray.
•More current than normal may be required to elicit a response by means of
the electric pulp tester.
•Internal resorption[2,4] is an idiopathic slow or fast progressive
resorptive process occurring in the dentin of the pulp chamber or root
canals of the teeth
•The cause of internal resorption is not known,but such patients often
have a history of trauma.
•Internal resorption in the root of a tooth is asymptomatic.
•In the crown of the tooth ,internal resorption may be manifested as a
reddish area called”pink spot”.
•Resorptive defect is more extensive in pulpal wall than on the root
•The defect is usually is recognised by means of a radiograph.
Necrosis of pulp
•Necrosis is death of the pulp.
•It may be partial or total, depending on whether part or the entire
pulp is removed.
•It can be caused by any noxious insult to the pulp , such as
bacteria, trauma ,and chemical irritation.
•A normal tooth with a nerotic pulp cause no painful symptoms.
•The presence of necrotic pulp may be discovered only by chance
because such tooth is asymptomatic ,and the and the radiograph is
•The teeth with partial necrosis can respond to thermal changes
,owing to the presence of vital nerve fibers passing through the
adjacent inflamed tissue.
Tooth with necrotic pulp does not respond to cold ,the electric
pulp test ,or the test cavity
Normal Patient reports a thermal sensation and stops
feeling it when the stimulus is removed
Reversible pulpitis Thermal sensation causes discomfort/pain and
the magnitude of response is different from
adjacent and/or contralateral teeth;sensation
may linger briefly
Symptomatic irreversible pulpitis After thermal stimulus is applied, patient reports
pain/discomfort is more pronounced than on
adjacent teeth and/or contralateral
Asymptomatic irreversible pulpitis Same response as normal or reversible pulpitis,
except the patient has a
history of pulpal inflammation such as caries,
carious exposure, or trauma
Necrosis Patient reports feeling no sensation when
thermal stimulus is applied for more than 15
seconds in case of cold test n more than 5 sec in
case of hot test.
Possible Diagnoses, based on patient responses to thermal stimuli.
Types of Nerve Fibres and their
distribution inside the dental pulp
• Dental pulp is a highly innervated tissue that
contains sensory trigeminal afferent axons
• N trigeminal sensory nerve fibers
– 90% of A fibres are A –delta fibres , which are located at
the pulp-dentin border in the coronal portion of the pulp
and concentrated in the pulp horns
– C fibres are located in the core of the pulp and extend into
the cell –free zone underneath the odontoblastic layer
• Sympathetic efferent fibres regulate the blood
Pulp tests and innervation
• Electric current simulates Aδ-fibres, but not the C-fibres,
because their high threshold.
• Cold stimuli produce stronger response than hot stimuli,
because of the outward flow of fluid.
• Repeated application of cold will reduce the displacement of
fluid – less painful.
• Aδ-fibres are more affected by the reduction of blood flow
than C-fibres, because they more sensitive to hypoxia.
• Uncontrolled heat can injure pulp release mediators that
affect the C-fibres.
Comparison of pulp tests
sensitivity 0,83 0,86 0,72
specificity 0,93 0,41 0,93
Recovery of traumatic teeth function
Test 0. day 28. day 2 month 3 month
100% 100% 100% 100%
Electric test 0 29.4% 82,35% 94,11%
Heat test 0 29,4% 82,35% 94,11%
Differentiation of reversible/irreverisible
The diagnosis of the state of the dental pulp is frequently
given insufﬁcient attention by many den- tists, and where
doubt exists root canal treatment is too often performed,
even though it is a costly procedure, and may reduce the
prognosis for the restored tooth. The profession needs to
re-evaluate its attitude to diagnosis of pulpal and
periapical conditions for the beneﬁts of patients.
Attempts at measuring the pulpal blood flow clinically
have mixed success, with LDF being one of the popular
technique applied in dental traumatology. Currently, no
vitality test have been proven to be superior in all aspects
compared to pulp sensibility test.
Further research is going on to improve all aspects of
diagnostic pulp tests.
1. Eugene Chen and Paul V. Abbott Review Article Dental Pulp Testing Page 2-4
Text of Grossman’s Endodonti practice
Page no 84-75
3. Samraj RV
Recent advances in pulp vitality testing
Page no 3
4. Stephen cohen Kenneth M. Hargreaves
Text book of Pathways of the pulp
5. Velayutham Gopikrishna
Article on Evaluation of Efficacy of a New Custom-Made Pulse Oximeter