Assessment of pulp vitality

Neural sensitivity test

1. Assessment of Pulp Vitality Neural Sensitivity Test Submitted by: Anup Ojha BDS 141 4 th Batch Submitted to: Department of Conservative and Endodontics Dr Sanjeev Chaudhary Dr Archana Gharti Dr Bhawana Adhikari

2. Assesement of Pulp Vitality Neural Sensitivity Test Thermal Test Electric Pulp Test Anesthetic Test Test Cavity Pulp vascularity test Pulse oximeter Laser Doopler flowmeter Recent technologies Dual wave spectrophotometry Thermography Crown Surface temprature Transmitted light photoplethysmography

3. Pulp Vitality : Assessment of pulp blood supply. Pulp Sensibility : Assessment of pulp sensory response. Pulp Sensitivity : Condition of pulp being very responsive to a stimulus.

4. Content Indication and Limitation Thermal Test Anesthetic Test Test cavity Summary Past question

5. Neural Sensitivity Test Indicate neural response from pulp. Neural sensitivity also does not indicate the vitality of pulp.

6. Indication Referred pain in trigeminal area to assess the status of pulp of individual teeth. Trauma to teeth, predict the state of pulp, if no response indicate pulp has gone necrosis. Before restoration to determine if pulp is healthy or not.

7. Limitation It only measures pulp nerve response not pulp blood flow. Not effective in older patient because of closed dentinal tubules and secondary dentine formation. Extensive restoration, pulp recession and extensive calcification creates limitation . Not reliable in children.

8. Thermal Test It involves the application of heat or cold to tooth surface to determine the sensitivity on thermal change. Material use Heat Test Cold Test Electrical Heat Carrier Endo ice (-50 ° C) Hot Gutta Percha stick (>65.5 ◦ C) CO 2 ice (-72 ◦ C) Other : Hot water Under rubber dam Pencil of ice (0 ° C) Hot burnisher Ice cold water under rubber dam isolation Dry rubber polishing wheel Ethyl chloride (-4 ◦ C ) Hot Compound

9. Principle Two types of sensory fibers are present in the pulp: the myelinated (A fibers) and unmyelinated C fibres . Approximately 90% of A fibres are Aδ fibres . Aδ fibers mediate acute, sharp pain and are excited by hydro mechanical events in dentinal tubules such as drilling or air-drying. The C fibers mediate a dull, burning, and poorly located pain , and are activated only by stimuli reaching the pulp proper.

10. Thermal test activate hydrodynamic fluid movement with in the dentinal tubules which activates Aδ fibres . C fibers are activated unless there is injury. On application of heat there is stimulation of fluid movement within the dentinal tubules that stimulates the odontoblast and its associated fast conducting A δ fibers. If continuously heat applied more likely to stimulate slower conducting C fibers.

11. Cold stimulates the fast-conducting A- δ fibres

12. Heat Test Indicated to patient who have pain on eating or drinking hot food. Heat causes the fluid to expand, stimulating the A- δ fibres ; However , when heat is applied to an inflamed pulp, the pressure increase can stimulate the C fibres and produce a long lasting pain.

13. Material used Electric heat test: Lubricant is applied on teeth b efore test. Patient will inform the pain on application. Hot Gutta Percha Stick (> 65.5◦ C) Heated until it becomes soft and glistering Teeth give response within 2 seconds

14. Lubrication is applied over tooth surface. Applied on facial or lingual middle third of crown Hot water under rubber dam (80-85 ◦ C) Individual teeth by applying rubber dam and with the help of syringe with blunt needle bathing is done. Most effective than other method because it covers or bath entire crown portion.

15. Hot burnisher Burnisher is heated over the flame and applied close to the buccal aspect of tooth surface without touching it. Radiant heat is produced.

16. Dry rubber polishing wheel A pplied to the buccal aspect of a tooth without prophylactic paste and rotated within a dental handpiece to produce frictional heat.

17. Heat Test Prolonged heat application will result in bi-phasic stimulation of Aδ fibres initially, followed by the pulpal C fibres . Continuous application of heat results in vasodilation and increase in intrapulpal pressure due to stimulation of C fibers. C fibres may result in a lingering pain, therefore heat tests should be applied for no more than 5 second.

18. Mechanism of Heat Test: Heat application for < 5seconds . Vasodilation Increased in intrapulpal pressure Reduce neural excitation threshold Immediate excruciating pain OR pain lingers even after removal of stimulus. Irreversible pulpitis positive response similar to contralateral control Healthy state of pulp. No response on heat application Non vital tooth.

19. Cold Test Cold test can be applied with several ways. One of the method is cotton pellet applied with 1,1,1,2 tetra fluoroethane . Wrap a silver of ice in wet gauge and place it in facial surface of tooth and compare it. Pencils of ice can be made by discarded anesthetic capsule with water and freezing them in anesthetic solution. Carbon di oxide snow can be placed.

20. Cold thermal testing causes contraction of the dentinal fluid within the dentinal tubules, resulting in a rapid outward flow of fluid within the patent tubules. This rapid movement of dentinal fluid results in ‘hydrodynamic forces’ acting on the Aδ nerve fibres within the pulp–dentine complex, leading to a sharp sensation lasting for the duration of the thermal test.

21. Ice Stick Ice sticks can be formed by freezing water in the plastic covers. Placed in gauze to prevent warmth from the operator’s Fingers The use of ice appears to be of limited value when testing teeth under crowns and splint. It has been indicated that the application of an ice stick for a period of 5 s is a reliable.

22. Ethyl Chloride Chloroethane , with a temprature of -21 °C. It is colourless , flammable gas with sweet odour , available in compressed spray. The use of ethyl chloride in pulp testing is no longer recommended because it has been found to be less effective than dry ice or DDM

23. Endo Ice The most convenient and easiest to use. They are based on dichlorodifluoromethane (DDM ), tetrafluoroethane (TFE), or a propane–butane mixture (PBM) Ranges from -20 to -50 ° C.

24. Use with cotton pellet , Endo Ice is sprayed in cotton pellet and applied over individual tooth. DDM produced the greatest reduction in intrapulpal temperature when applied by a saturated cotton pellet rather than via a cotton tip.

25. Carbon di oxide snow: Temprature -78 ° C The sensory response to the application of dry ice is rapid, usually being <2 s. Mechanism Depends upon hydrodynamic theory , application of cold to a tooth results in rapid movement of dentinal fluid that mechanically stimulates the sensory terminals located in the region of the PDJ .

26. Technique: It is compacted with a plugger and the ‘ pencil’ or ‘stick’ of dry ice is expressed slightly from the tube and then applied immediately to middle-third of facial surface of crown for 2-5 s until patient feels pain.

27. Advantages Complete dentition can be tested without isolation of teeth. More accurate response than ice, penetrates restoration ,splints and reach the deeper area. No false reading in pulp necrosis. Disadvantages Not effective with calcified pulp. More expensive.

28. Cold water Bath A tooth or a group of teeth can be isolated with a rubber dam, and iced water can be syringed onto each tooth. This method is effective for evaluating teeth with full coverage restorations, either metal or porcelain. The sensory response of teeth is refractory to repeated thermal stimulation. Another benefit of this method is that it needs no armamentarium except for rubber dam

29. Mechanism of cold test Cold application for 15 seconds.   A postive response similar to contralateral control tooth Healthy pulp Short sharp pain that disappear rapidly once stimulus is removed. Reversible pulpitis An excruciating painful response that lingers on even after the stimulus is removed Irreversible pulpitis If no response to this test tooth is non vital.

30. Anesthetic Test Objective is to anesthetize one tooth at a time until the pain disappears and localized to a specific tooth. Most posterior tooth in area of suspected pain is anesthetized either by intra ligamentary or infiltration . If the pain persists when the tooth is fully anesthetized, next tooth mesial to it is anesthetized and continue until pain disappear.

31. If the pain cannot be identified Inferior alveolar block is given. Cessation of pain naturally indicated involvement of mandibular tooth , localization of specific tooth is done by intraligament injection.

32. Test Cavity It determine pulp vitality. Drilling with high speed and water coolant through enamel dentin junction of an unanaesthetized tooth. Sensitivity or pain is felt by patient indicates pulp vitality, no endodontic treatment is indicated. If no pain is felt during cavity preparation until pulp chamber is reached .

33. If pulp is completely necrotic endodontic treatment is continue without anesthesia.

34. Clinical Consideration Normal Pulp: A symptomatic and produces a mild to moderate transient response to cold and does not response to heat test. Reversible Pulpitis : Thermal Stimuli causes sharp pain that subside as soon as stimuli is removed . Cold test is usually preferred.

35. Irreversible pulpitis Symptomatic irreversible pulpitis: After thermal stimulus is applied, patient reports pain/discomfort is more pronounced than on adjacent teeth and/or contralateral tooth 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

36. Pulp necrosis : No response will be obtained. Calcified Pulp: No response from thermal test. Teeth which have received root canal treatment will not receive respond from cold test but response to heat test.

37. Multi rooted tooth. Limitation in multi rooted tooth,pulp may be vital in one canal but not in another canal. May response to cold test. T he pulp chamber and other canals might be necrotic and infected.

38. No response to a test might occur when the patient has been pre-medicated with sedative, tranquillizing, analgesic or anti-inflammatory medications, or alcohol Following injury, traumatized teeth may not respond to thermal or EPT due to nerve rupture. The pulps of these teeth, however, may still be vital as their blood vessels remain intact or have revascularized . Cold test appears to be more reliable, recently trauma , hyperactive response.

39. W hen extensive restorations and pulpprotecting bases have been placed unusual high pain threshold. False negative response from the incomplete root development, because it requires high threshold and stronger stimulation to test , due to incomplete neural development.

40. Summary Pulp tests include sensibility and vitality tests. Sensibility tests are the most commonly performed in clinical practice owing to their simplicity and low cost . Accuracy of cold test is 86% and EPT 81% and heat test is 71% hence combination of cold test is followed by EPT is recommended . It is essential that clinicians understand the limitations of these tests and their usefulness . A diagnosis of the state of the pulp can only be reached once all the information has been gathered and assessed .

41. Past question Short notes on Thermal test ( 2061/1)

42. References: International Endodontic Journal , Pulp sensibility tests , Jafarzadeh & Abbott 2010 Grossman Endodontic Practice 12 th Edition.