Endodontic diagnosis
The art of diagnosing a condition and planning the treatment accordingly is first step for a successful outcome of a treatment. Correlation of the clinical and the radiologic findings will help to arrive at a proper diagnosis and this section covers the diagnostic aids, the tests and their possible responses .
1. Why a proper radiographic interpretation is important in endodontics?
Radiographs show areas of resorption, invaginated enamel, fracture lines, extra roots and canals, curvature of the canals and calcifications and all these may create problems during treatment. Also many anatomic structures like mental & incisive foramen and osteolytic lesions like periapical Cemental dysplasia or cementoma may be confused for a periapical lesion and all these need radiographs at different angulations and also pulp testing procedures.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,120
2. Why are periapical x-rays taken during endo treatment of a tooth?
During endodontic treatment , periradicular x- rays are essential to determine the working length , the location of the canals and anatomic landmarks, instrumentation in the canal, master cone adaptation and finally after the treatment completion, to determine the quality of the obturation. Radigraphs taken in the recall visits help to assess the success or failure of the treatment.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,114
3. Why is a post endodontic restoration essential?
For an endodontically treated tooth, a post endodontic restoration is needed but it has to be assessed before endo treatment is performed based on the amount of sound tooth structure that will be available for a restoration to be placed. In other words endo treatment is advised only for teeth that can have a post endo restoration because loss of tooth structure weakens the tooth and makes it more susceptible to fracture. So it has to be protected with a restoration.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,107.
4. Why does an endodontically treated tooth discolor?
If the treatment is done properly, discoloration never occurs. Some of the teeth discolor because of staining of the tooth coloured restorative materials on them or leaching of silver ions from amalgam restorations on endodontically treated teeth. The discoloured fillings are replaced or veneers or crowns are placed.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,107
5. A sensitive tooth requires a careful history and clinical examination – Why?
The sensitivity of a tooth is due to the exposed dentinal tubules. When there are specific causative factors for the sensitivity, such as caries , fracture or defective or recent restorations, the teeth may show symptoms similar to dentinal hypersensitivity, but this is mainly due to a reversible pulpitis in these teeth with vital pulps. So a proper clinical and radiologic examination is essential along with a proper history for a sensitive tooth.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,36
6. What is hyperplastic pulpitis?
It is a reddish growth of the pulp tissue through the carious exposure which is due to a low grade, chronic irritation of the pulp. It is highly vascularised and common in young people. It is also known as pulp polyp. Sometimes there may be pain during mastication and it requires endodontic management.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,27
7. Why does a pink spot on the crown of the tooth needs radiological evaluation?
The pink spot on the crown of the tooth is due to a process called internal resorption. It is a painless condition involving osteoclastic cells, stimulated by trauma, producing destruction of dentin. This is identified by routine radiographs . If it is not detected early, it can perforate the root or the crown. Before perforating the crown, it appears as a pink spot. Endodontic treatment will stop the destruction.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,27
8. Why are angulated x-rays taken in endodontics?
The mesial or distal angulation view shows the presence of additional roots, extra canals and the curvature of the canals and roots . The direct view x- ray is 2 dimensional which may superimpose the additional roots or canals. So angulated x- rays are taken.
Ref: Franklin S.Weine,Endodontic therapy, Mosby , 6th Edn,49.
9. Why are radiographs needed to differentiate between an acute periradicular abscess and a phoenix abscess?
Clinically, acute periradicular abscess and phoenix abscess have the same features like swelling, pain on percussion and palpation & slight mobility of the tooth. But radiographically, acute periradicular abscess may manifest as a slight thickening of the periodontal ligament only, since it is a rapid progress of infection beyond the confines of the cortical plate before demineralization is detected radiographically. Whereas in phoenix abscess , which is an acute exacerbation of a chronic abscess, a periapical radioluscency is evident that is indicative of a chronic disease.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,28
10. Why does a tooth with acute apical periodontitis need pulp testing before commencing endodontic treatment?
Acute apical periodontitis is a painful inflammatory condition occuring around the apex of the root. It can occur as an extension of the pulpal inflammation or by occlusal trauma caused by hyperocclusion or bruxism. Since it occurs around teeth with vital as well as non vital pulp, an electric pulp testing or a thermal test should be performed to confirm the need for endodontic treatment.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,28
11. Why a tooth with necrotic pulp is non responsive to the Electric pulp tester?
Necrosis is the death of the pulp which may be due to an untreated irreversible pulpitis or any other reason which disrupts the blood supply to the pulp and it may be total or partial. Total necrosis is asymptomatic before it affects the periodontal ligament as the nerves in the pulp are not functional. So the tooth does not respond to EPT or other thermal stimuli.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,28
12. Why radiographs are not useful in diagnosing symptomatic irreversible pulpitis at an early stage?
In the early stages of irreversible pulpitis, the inflammation remains confined only to the pulp. It is possible only to find the offending tooth which may be a carious tooth or teeth with extensive restorations. Whereas in the advanced stages, the apical periodontal ligament may be thickened in the radiograph and it is symptomatic clinically also.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,27
13. What are the features that say that the pulp is normal?
The pulp is said to be normal when the tooth is asymptomatic with mild to moderate transient response to thermal and electrical testing and is momentary, no painful response to percussion and palpation. The radiographs show a tapering canal towards the apex. The roots are not resorbed and there is an intact lamina dura.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,26
14. What is a Cracked Tooth syndrome?
It is a hairline incomplete fracture of the tooth, where the patient experiences a sporadic, sharp pain while chewing and an occasional pain from cold food or drink. The pain occurs because of separation of the crown by occlusal forces and exposure of the underlying dentin. The pain is due to the hydrostatic fluid movement. Transillumination locates the tooth.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,25,26
15. Why are radiographs only adjuncts in the diagnosis?
Radiographs have certain limitations like: It is a two dimensional picture of a three dimensional reality. There may be inter observer variations in the interpretations. The status of the health and integrity of the pulp is not determined. Radiographs always tell us about the past status of the pulp and not the present status of the pulp.So other aids have to be used along with radiographs for a proper diagnosis.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,18,19
16. Why does false positive response occur while using an electric pulp tester?
False positive responses can occur in a variety of situations like when the patient is anxious, presence of saliva conducting stimulus to the gingiva, presence of metallic restorations conducting stimuli to the adjacent teeth, liquefaction necrosis that conduct the stimuli to the attachment apparatus, multirooted teeth with a combination of vital and non vital canals, large restorations involving many surfaces and teeth with splints and bridges.
Ref: Franklin S.Weine,Endodontic therapy, Mosby , 4th Edn,58,59. Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,16.
17. Why electric pulp tester is considered as an important diagnostic aid for diagnosing pulpal and periodontal lesions?
Clinically, acute alveolar abscess and acute periodontal abscess have similar features. An evaluation with the Electric pulp tester can identify the origin of the swelling and the problem tooth. Even if it is a periodontal lesion, the pulp is also evaluated as an adjunct to the periodontal treatment, to rule out any pulpal pathology. No response of the pulp with electric pulp tester denotes that the lesion is of pulpal origin, whereas positive response of the pulp with EPT denotes the lesion is probably because of periodontal origin.
Ref: Franklin S.Weine,Endodontic therapy, Mosby , 6th Edn,59
18. Why are the responses to thermal tests recorded to arrive at a diagnosis?
A proper knowledge of the responses to the thermal tests is essential to arrive at a diagnosis because each response is indicative of a particular clinical condition. The pulp is considered non vital, when there is no response. A mild to moderate response is of a normal pulp. There is an exaggerated response,subsiding quickly in a tooth with reversible pulpitis and in irreversible pulpitis, there is a lingering pain even afer the stimulus is removed.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,15
19. Why thermal pulp testing is a valuable diagnostic tool?
Sudden Temperature changes on the teeth may initiate or relieve pain which is helpful for the diagnosis of certain conditions. The patient’s reaction after heat application helps to locate the problem tooth. A sharp non-lingering pain to heat application is a normal response. So thermal pulp tests are valuable in diagnosis.
Ref: Franklin S.Weine,Endodontic therapy, Mosby , 4th Edn,56. Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,13
20. Why reversible pulpitis is not a disease, only a symptom?
In reversible pulpitis , the pain subsides once the stimulus is removed. If the irritant in the tooth with reversible pulpitis is removed,and the tubules are sealed from further insult, the pulp reverts to an asymptomatic uninflamed state. But if the irritant remains and the symptoms persist, an irreversible pulpitis may result.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,27
21. Why the electric pulp tester is not used to check the vitality of the tooth?
The electric pulp tester uses electrical stimulation to the A- delta sensory fibres within the pulp. It fails to provide information whether the vascular supply is intact or not, which truly determines pulp vitality. So a positive response does not mean that the pulp is healthy. It only indicates that vital sensory fibres are present in the pulp.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,15
22. How is the percussion test done during the diagnosis phase?
Percussion is first performed with the right index finger beginning with the least suspect tooth and then to percuss the occlusal, buccal and lingual surfaces with the handle of the mouth mirror.
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 47
23. How does percussion aid the diagnosis of the problem tooth?
Gentle percussion of a tooth affected by inflammatory process causes pain to the patient, which is a sure sign of the lesion involving the periodontal space. On the other hand, a negative response need not be a sign of good health, because chronic inflammation is asymptomatic.
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 47
24. How is the heat test performed to check the vitality of the tooth?
A piece of Gutta percha wrapped around the spatula or an old instrument is heated over a flame to a point at which it is too hot to be touched, not more than about 650 c and placed at the apical third of the buccal surface where the enamel is the thinnest.
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 56
25. Why is the hot GP placed in the thinnest area of enamel?
The heat test assesses the dentinal sensitivity. The enamel is a poor conductor of heat and electricity. So the test is performed at the thinnest area.
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 56
26. How is the heat test performed on a tooth with full gold crowns?
On teeth with full gold crowns, heat test is performed with a polishing rubber disc in a rotary handpiece revolving at a low speed, generating frictional heat against the metal. Or the tooth can be irrigated with very hot water after rubber dam isolation.
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 57
27. Why is percussion test done in diagnosing the diseased tooth?
Percussion stimulates the proprioceptors of the PDL. It determines the presence of inflammation in the PDL. But it does not give any information about the state of health of pulp.
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 47
28. Why radiographs are not the sole diagnostic tools in endodontics?
Radiography is a 2 dimensional representation of an object existing in 3 dimensions. For multirooted teeth, overlapping may occur and it is necessary to take with different angulations. Moreover, radiographs cannot assess the vitality of the pulp. In other words, all periapical lesions are not visible radiographically. The lesion must involve the cortical bone to be visible radiographically. For all these reasons, radiographs cannot be taken as the sole diagnostic tool
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 49
29. Why radiographs are not the sole diagnostic tools in endodontics?
Radiography is a 2 dimensional representation of an object existing in 3 dimensions. For multirooted teeth, overlapping may occur and it is necessary to take with different angulations. Moreover, radiographs cannot assess the vitality of the pulp. In other words, all periapical lesions are not visible radiographically. The lesion must involve the cortical bone to be visible radiographically. For all these reasons, radiographs cannot be taken as the sole diagnostic tool
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 49
30. What are the points to be kept in mind while taking a radiograph in endodontics?
The radiographic film should show the entire tooth, from the crowns to the alveolar bone surrounding the root apex, the entire periphery of the lesion and the tooth examined should always be centered. The film should be positioned with appropriate holders
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 49
31. What is the difference in response of a normal pulp and a necrotic pulp to thermal stimuli?
Healthy pulp is normally sensitive to hot or cold stimuli and this sensitivity disappears shortly after the stimulus is removed. A necrotic or inflamed pulp either does not respond or responds in an exaggerated and prolonged manner
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 56
32. Why does the thermal test usually done in the least suspect tooth first?
The test should be begun from the least suspect tooth because the patient’s anxiety should be reduced and should experience the response of a normal pulp before proceeding to test the diseased tooth
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 56
33. How does a normal pulp respond in cold stimulus?
The normal pulp responds to cold in a similar way as hot stimulus. The pulp has no specific receptors and the neural fibers in the pulp transmit only the sensation of pain. The patient should not feel pain, but only a moderate sensation, that recedes immediately after removal of the stimulus
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 58
34. What does a response that deviates from a simple moderate response indicate?
Responses to thermal tests, when they deviate from the simple moderate response, in other words, pain persisting even after the stimulus, severe pain or no response at all, indicate that the tested pulp is not healthy but variably inflamed
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 58
35. What is the significance of lack of response to thermal testing?
Lack of response to thermal testing is suggestive of either a necrotic pulp or a false negative response that can occur in excessive calcification, immature apex, recent trauma or patient premedication
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 58
36. Why is the electric pulp test not useful to know the pulp vitality?
The electric pulp testing is done with an instrument that can stimulate the neural elements in the pulp. So the test gives information about the presence or absence of the neural fibers only and does not tell the status of blood supply to the pulp, which actually determines pulp vitality
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 59
37. Why care is taken when the instrument tip is placed in the cervical area while performing EPT?
The instrument tip is placed in the cervical area only since the enamel is thinnest in that area. Care should be taken to avoid contact of the instrument with gingival tissue or with any restoration since that could create a false response
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 60
38. Why does a tooth that had a recent trauma give false negative response?
A tooth that has had a recent trauma may give a false negative response because the fibres are in a shock and the normal response will not return for 30-60 days
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 60
39. How is the cavity test performed to determine pulp vitality?
A small cavity is prepared on the occlusal surface of the posterior teeth or on the palatal surface of the anterior teeth using a small round bur mounted on a high speed handpiece, without anesthesia. If the pulp is vital, the patient will experience a sudden slight pain
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 62
40. Why is medical history important before starting the endodontic treatment?
Endodontic therapy has no systemic contra indications. But a medical history is important because antibiotic prophylaxis is required when the patient had a prosthetic valve replacement, any H/o rheumatic fever or malignancy requiring chemotherapy/ radiotherapy. For Patients with hepatitis, herpes/ AIDS, the patient, the operator and the assistant have to be protected from infection. The operator and the assistants have to use rubber gloves, face mask and protective eye shields
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 44
41. In the dental history, when the patient has pain, what are the points to be noted?
When there is pain, its location (localized or diffused), its origin (spontaneous/ provoked), reproducibility, character (sharp, dull, lingering / throbbing), duration (continuous / intermittent) and postural variations have to be recorded
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 44
42. What is the inference of doing a percussion test?
Gentle percussion of the affected tooth causes pain to the patient. So a positive response indicates that an inflammatory process involves the periodontal space which is of an endodontic origin. A negative response is not a definitive sign of good health because the lesion may be chronic which is asymptomatic or the pathology is limited to the pulp
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 47
43. How and why is palpation of soft tissues performed?
A light application of digital pressure on the soft tissues of the oral cavity is performed to identify the painful areas due to the spread of inflammation from the periodontal ligament to the overlying periosteum. Usually palpation is done with right index finger and is done simultaneously on the contralateral tooth also for comparison
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 47,48
44. What information does palpation provide before arriving at a diagnosis?
Apical periodontitis can be revealed at an earlier stage. The limits of the inflamed and the swollen areas can be delineated which aids in insertion of the scalpel during drainage of an abscess. When there is an abscess, palpation assesses whether the underlying swelling is soft or fluctuant. The condition of the sub mandibular / cervical lymph nodes can be assessed. Also the mobility of the teeth or the presence of an alveolar fracture can be checked
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 48
45. Why does a necrotic tooth need not show radiographic changes?
A necrotic tooth need not have radiologic abnormalities because changes are visible in the radiograph only when the periapical pathology destroys the osseous trabeculae at the point of union with the cortical bone.
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 48
46. Why is the radiograph considered to be a very informative diagnostic aid?
The radiograph is considered very informative since it shows the presence or extent of carious lesions, the closeness of old restorations to the pulp, presence of pulp therapies, calcifications, root resorption, presence of periradicular radioluscensies, fractures, thickness of PDL, periodontal disease, number of roots and their width and length, dentinal wall thickness and the degree of root curvature, all of these will help for the success of endodontic therapy.
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 48,49
47. Why should radiographs be combined with other diagnostic aids always?
Since radiographs are two dimensional representation of a three dimensional object, it can be erroneously interpretated. So it is always advised to combine with other diagnostic aids.
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 48
48. How does the necrotic pulp differ from a healthy pulp in responding to a thermal test?
Healthy pulp is normally sensitive to hot/ cold stimuli which disappear shortly after the stimulus is removed. A necrotic or inflamed either does not respond or responds in an exaggerated or prolonged manner.
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 56
49. What responses to thermal test suggest that the pulp is not healthy?
Responses like pain that resolves slowly even after the removal of the stimulus, very acute pain and no response at all suggest that the pulp tested is not healthy but variably inflamed.
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 58
50. How does a multi rooted tooth respond to electric test when the pulp is necrotic in one canal and vital in others?
Diseases of the pulp proceed in a corono apical direction with the pathological process beginning in a pulp horn, propagating to the pulp chamber and then the root canal. When electric pulp test is performed, the pulp of the pulp chamber is only tested. In a multi rooted tooth, even if only one canal is necrotic, all the pulp in the pulp chamber would also be necrotic. So the tooth will respond negative to EPT and will be considered as a necrotic tooth only.
Ref: Endodontics,Arnaldo Castelluci,IL Tridente, vol 1; 61