Pulp Vitality Test
Dr- Rasha Al- ShamaaIntroduction
Diagnosis defined as the process whereby the data obtained from questioning, examining and testing are combined by the dentist to identify deviations from the normal Vitality testing is an important aid in the diagnosis of pulp disease and apical periodontitis.Pulpal innervation
Within the coronal pulp, nerve bundles diverge and branch out towards the pulpo-dentine border, and emerge from their myelin sheaths Nerve divergence continues until each bundle looses its integrity and smaller fibers groups travel towards the dentine. This course is relatively straight until the nerve fibers form a loop and a resultant mesh termed the nerve plexus of RashkowDefinition
Pulp Vitality Testing: Assesment of the pulp’s blood supplyPulp Sensibility Testing: assesment of the pulp’s sensory responsePulp Sensitivity : condition of th pulp being very responsive to a stimulusPulp Testing Techniques/Pulp Senibility Testing
Thermal Tests Cold tests: Ice Refrigeant Spray (chlor-etil, dichlor-difluorometane-DDM, tetrafluoro-etane TFE) Carbon-dioxide snow Heat test Warm gutta-percha Touch and heat Electric pulp test Test cavity preparationTwo types of sensory fibres
The myelinated (A fibers) and unmyelinated C fibers A fibres (Dentin)C fibres (Body of the pulp)
Aβ Aδ Aδ
Pulp Vitality Testing
Other: Photoplethysmography : to improve pulse oximetry , by adding a light with a shorter wavelength Spectrophotometry: dual wavelength lights Transmitted Laser Light (TLL): separated sending/receiving probesPulp Vitality Testing
Transillumination: colour changes that may indicate pulp pathosis Ultraviolet light photography: fluoresens patterns Surface temperature measurment (breathing)Thermal Test
The response of the pulp to the heat and cold is noted. The basic princible of the pulp to respond to pulp stimuli is that the patient report sensation but disappear immediately. Any other type of respond i.e painful sensation after removable of stimuli,or no response are considered abnormal.Thermal test-Cold Test
Isolation the tooth with rubber dam, this is mandatory with all types, it recommended when uses ice-sticks due to melting ice run to the adjacent teeth and gingival result false positive result.Thermal test-Cold Test
Commonly used method for performing this test as following: Spraying cold air directed to the isolated tooth. Application of cotton pellete saturated with ethyl-chloride. Spray of ethyl chloride after isolation the tooth with rubber dam.(The ethyl chloride evaporated so rapidly that it absorbs heat and thus , cools the tooth).Thermal test-Cold Test
Thermal test-Cold Test
Application of dry ice on the facial surface of the tooth after isolation of the soft tissue and teeth with the cotton pellete. The frozen carbon dioxide (dry ice) is available in the form of solid sticks having extremely low temperature , it should not come in contact with oral mucosa due to it cause soft tissue burns.Thermal test-Heat Test
The easiest method is to directed the worm air to the exposed surfaces of the tooth and noted the patient response. If the higher temperature is needed to illicit a response , then other option is needed i.e heated stopping sticks , hot burnisher, hot water ect. can be usedThermal test-Heat Test
Heated gutta percha sticks is most commonly used method for heat test. Tooth is coated with a lubricant such as petroleum jelly to prevent gutta percha from adhering to the tooth surface. The heated gutta percha is applied at the junction of cervical and middle third of the facial surfaces of tooth and patient response is noted.The other methods of heat testing frictional heat produced by rotating polishing rubber disk , deliver warm water from syringe (especially useful of teeth with the porcelain or full coverage restoration).
Electric Pulp Testing
This test is used for evaluation of condition of the pulp by electrical excitation of neural element within the pulp. The pulp tester is an instrument which uses the graduation of electrical current to excite a response from the pulp tissue. A positive response indicates the vitality of the pulp, no response indicate pulp necrosis (The probe can be placed in contact with natural teeth )Electric Pulp Testing
The electric pulp tester is a battery-operated instrument, which is connected to a probe that is applied to the tooth under investigation. 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.Electric Pulp Testing
Electric Pulp TestingThe intensity of the electric stimulus is then increased steadilyat a pre-selected rate, and a note is made of the read-out on the digital display when thepatient acknowledges a warm or tinglingsensation.The read-out simply provides evidence that the Aδ fibres are sufficiently healthy to function.
Electric Pulp Testing
The tip of testing probe in contact with the tooth structure ,coated with water or petroleum media (tooth paste ). The coating probe placed on incisal third of buccal or facial area of tested tooth .The requirements of an EPT are:
an adequate stimulus an appropriate application method Careful interpretation of results. Tooth isolation during EPT is essential. Drying the enamel, placement of an interproximal plastic strip, and use of rubber dam can prevent the spread of electrical impulses to adjacent teeth or gingival tissue Electric current can also be transferred between adjacent teeth through contacting metallic restorationsTest Cavity Preparation
This test may serve as a last resort in testing for pulp vitality. It is only considered when the results of all other tests have proved inconclusivedrilling through the enamel–dentine junction of an un anaesthetized tooth with good isolation. This may be achieved under rubber dam with a small round diamond bur in a high-speed hand piece with adequate coolant.Local anaesthetic test
In special clinical situations, the use of intraligamentary anesthesia is an effective diagnostic tool. For example, If the patient continues to have vague, diffuse, strong pain, and prior testing has been inconclusive patients may not even able to specify whether the symptoms are from the maxillary or mandibular archLocal anaesthetic test
Local anaesthetic testinferior alveolar nerve block injection is given; cessation of pain indicates involvement of a mandibular tooth.
Limitations of sensitivity testing False-positive
A false positive response is where a non-vital tooth appears to respond positively to testing . anxious or young patients who may report a premature response because they are anticipating an unpleasant sensation. Necrotic breakdown products in one part of a root canal system can conduct electric currents to viable nerve tissue in adjacent areas. Contact with metal restorations may also result in conduction of the current to the periodontium. inadequately dried teeth.False negative
A false negative result means that a vital tooth has not responded positively to testing. teeth with incomplete root development, which have a higher threshold to testing, and require a stronger stimulation than normal to elicit a response. Following injury, traumatized teeth may not respond to thermal or EPT due to nerve rupture. orthodontic tooth. Patients with psychotic disorders.Recent advances in pulp vitality testing
Pulse Oximetry Dual Wavelength (Spectrophotometry) Laser doppler flowmetryLaser Doppler Flowmetry
Laser Doppler Flowmetry (LDF) is a noninvasive, electro optical technique, measures blood flow in the very small blood vessels of the microvasculature . The technique depends on the Doppler principle whereby light from a laser diode incident on the tissue is scattered by moving RBC's and as a consequence, the frequency broadened.Laser Doppler Flowmetry
The frequency broadened light, together with laser light scattered from static tissue is photo detected and the resulting photocurrent processed to provide a blood flow measurement. The Doppler shifted laser light, back- scattered out of the tooth is detected by a photocell on the tooth surface. The output is proportionate to the number and velocity of the blood cells.Laser Doppler Flowmetry
Laser Doppler FlowmetryPulse Oximetry
Another non invasive method, that has been investigated as a method to determined pulpal blood flow uses a pulse oximeter, which is designed to measure the oxygen concentration of blood and pulse rate . It work on the principle that two wave length of the light transmitted by photoelectric diode detected oxygenated and deoxygenated hemoglobin as they pass through a body part to a receptor.Pulse Oximetry
The difference between light emitted and light received is calculated by microprocessor to provide the pulse rate and oxygen concentration in the blood . The system consists of a probe containing a diode that emits light in two wavelengths: Red light of approximately 660 nm Infra-red light of approximately 850 nmPulse Oximetry
The probe is placed on the labial surface of the tooth crown and the sensor on the palatal surface. Ideal placement of the probe is in the middle third of the crown .Dual Wavelength Spectrophotometer
Dual wavelength spectrophotometry (DWLS) is a method independent of a pulsatile circulation. The presence of arterioles rather than arteries in the pulp and its rigid encapsulation by surrounding dentine and enamel make it difficult to detect a pulse in the pulp space. This method measures oxygenation changes in the capillary bed rather than in the supply vessels and hence does not depend on a pulsatile blood flow.Dual Wavelength Spectrophotometer
DWLS detects the presence or absence of oxygenated blood at 760 nm and 850nm. senses the oxygenated blood because of the greater absorption at 850 nm as compared to 760 nm. DWLS was able to differentiate with reproducible readings between a pulp chamber of a vital and non-vital toothDual Wavelength Spectrophotometer
Bite testsymptoms associated with incomplete fractures of posterior teeth. Bite tests can be performed using orange wood sticks, cotton wool rolls, rubber abrasive wheels such as Berlew wheels, or the head of number 10 round bur in a handle of cellophane tape. When using orange wood sticks to determine cracks, the patient is asked to bite on individual cusps separately. This helps to isolate the fractured cusp.
Bite test
Transmitted light photoplethysmography (TLP)TLP is a non-invasive technique used to monitor pulpal blood flow, and has been successfully applied in animal and human studies . It has been suggested that TLP incurs less signal contamination from the periodontal blood flow than is the case for LDF.