Endodontic Diagnosis Mystery or Mastery?

Countless articles and recent endodontic textbooks have focused on the science and art of endodontic diagnosis.1-6  Most of this literature is dedicated to pulpal histology and endodontic tests. The distinction of this article is threefold. First, it is designed to enable the restorative dentist to render the first aid of dental pain during a regular schedule. Second, this diagnostic scheme is a clinical approach. It is treatment according to symptomatology and objective tests. Third, the diagnostic treatment protocol is based on listening carefully to the patient in terms of what is occurring right now, an accurate history, testing the tooth, and then diagnosing and completing appropriate treatment. The purpose of this article, however, is to focus on listening to the patients current symptoms, duplicating his or her pulpal/periradicular symptoms, knowing exactly what emergency treatment to perform (if any), and the proper future treatment sequence. It is intended that this simple and effective approach can be used for endodontic diagnostic dilemmas that clinicians encounter every day. This article is divided into 4 parts: principles, distinctions, tests, and summary.

PRINCIPLES

PRINCIPLE NO. 1

Figure 1a. Principle No. 1: Most endodontic diagnosis is easy. Approximately 98% of pulpal problems can be detected by observing deep caries or restorations or by observing and verifying endodontic radiolucencies. Only about 2% of pulpal problems require accurate symptom duplication.

Approximately 90% of all teeth requiring endodontics are (or were) pulp exposures. In addition, approximately 8% of all teeth requiring endodontics are diagnosed by the presence of lesions of endodontic origin on the radiograph (Figure 1a). Furthermore, only approximately 2% of all teeth requiring endodontics require more sophisticated testing. Therefore, pulp exposures are often clear radiographically or can be detected clinically. The 8% of teeth that appear to have lesions of endodontic origin must probe within normal limits and must pulp-test nonvital, or they may involve a periodontic-endodontic diagnosis.7 If the pulp tests vital and the periodontal condition is healthy, then these lesions require a biopsy since they are not lesions of endodontic origin. The 2% of teeth that require further testing can easily be diagnosed using the 6 distinctions found in this article.

PRINCIPLE NO. 2

Figure 1b. Principle No. 2: Pulps typically die from a coronal to apical direction. This means that if a radiolucency is present, the pulp must test nonvital. It also means that if the pulp is pulpitic or thermal-sensitive, there will not be any evidence of radicular radiolucency. Therefore, it would be impossible to make a pulp ache diagnosis from a periapical radiograph since the radiograph would be normal.

Pulps die in a coronal-to-apical direction (Figure 1b). The direction of disease flow is due to the insult occurring in the coronal portion of a tooth. This can be due to caries,  multiple restorations, inadvertent severing of an infrabony lateral canal during curettage, or from traumatic impact.

 

 

 

 

 

 

 

 

 

 

PRINCIPLE NO. 3

Figure 1c. Principle No. 3: Though irreversible pulp inflammation can and does occur after a single restoration, it is more frequently due to 2 or more restorations. As the longevity of the US population increases and as the value of dental health (ie, keeping our teeth) and the value of aesthetics increase, more and more teeth will experience increased numbers of restorations over the lifetime of the patient, and more and more pulps will be challenged.

Pulps die multifactorially (Figure 1c). Since pulps are a microcirculatory system, pulps sometime die when the clinician least expects it. Pulps can become irreversibly inflamed after a buccal pit restoration, for example. This can be due to horizontally broad cervical pulp horns that are in the flat plane of the film and therefore cannot be detected radiographically. The pulp has 3 anatomic disadvantages. First, it is encased in unyielding walls of dentin; it therefore cannot fully benefit from the inflammatory response. Second, the pulp is a large volume of tissue for a relatively small blood supply. Third, the microcirculatory pulp is a terminal circulation, and like the appendix, can have a low recuperative capacity.

Most pulps survive the life of human beings. However, when there are multiple restorative procedures, every procedure adds to the possibility that the pulp will finally experience an irreversible condition. Because patients are living longer and are now requesting increased aesthetic restorative dentistry, pulps will continue to be compromised. It is unknown when the last insult required to create irreversible degradation will occur. The key here is for clinicians to pave their way with words and always inform the patient prior to any restorative procedure that the possibility of pulpal damage exists. This should be true whether the clinician is restoring one tooth or a full mouth.

SIX CLINICAL DISTINCTIONS

No. 1:  Pulp Exposure

Symptom: anything under the sun.

Duplicate: confirm pulp exposure clinically or radiographically.

Figure 2a. Clinical Distinction No. 1: Pulp Exposure. Note the icon suggests patients symptoms literally include anything under the sun.(Courtesy of Dr. Frank Casanova.)
Figure 2b. Periapical radiograph has limited value in evaluating the caries/pulp relationship.
Figure 2c. Bitewing of 2b periapical clearly shows that the caries nearest to the pulp is tooth No. 4. If the patient had a toothache, and since approximately 90% of teeth requiring endodontics are or were pulp exposures, tooth No. 4 is the most likely candidate to be the source of the toothache.

A pulp exposure is an easy diagnosis (Figures 2a through 2c). The symptom of a pulp exposure is not only any symptom under the sun such as hot, cold, bite, percussion, palpation, and just about everything else, but patients often will have a story. It is important to listen to this historical story because it will give clues to what the condition of the pulp is right now. For example, patients will tell you that last week they had a toothache but could not tell where the pain was coming from. Then they will talk about pain to cold and that it radiates down the jaw and that the pain is fleeting but it is intense. Then they might talk about pain to heat and where they were when they drank something hot and the discomfort that they experienced. Then they might talk about the tooth hurting when biting, or swelling or a sinus tract is now present.

The point here is that they had a pulp exposure previously, and the pulp has gone through multiple stages to perhaps necrosis or a more advanced stage of the disease. While the story has value in terms of making the diagnosis, the clinician needs to keep focusing on the final question to the patient, which is, What are you experiencing with your tooth right now? This will lead you to duplicate with the appropriate test. When removing caries or during a preparation, an exposed pulp can easily be detected radiographically. A pulp exposure is best suggested with a bitewing radiograph. Often the appropriate treatment for a pulp exposure is a socioeconomic question. As the dentistry becomes more extensive and expensive, fewer pulp caps are successful. If the clinicians fees for endodontics are extraordinarily low, then pulp caps appear more successful.

Dr. Gordon Christensen summarized pulp capping8 whereby he tested calcium hydroxide pastes, bonding agents, and Meta bonding agents. If these are not successful, he then suggests endodontics. Dr. Christensen summarized that pulp capping should be attempted only when small pulp exposures without excessive bleeding or purulent discharge are present...when crowns are planned or teeth are to serve as fixed partial denture abutments...probably should require endodontic therapy when these pulps are exposed.

Most dentists have discovered that pulp caps have increased success when they are small mechanical exposures, isolated with the rubber dam, no purulent discharge, and a nonstrategic restorative tooth. More recently, Torabinejad and Chivian have described clinical procedures in the application of mineral trioxide aggregate (MTA) in the capping of pulps with reversible pulpitis.9 They have been able to demonstrate histologic sections with a complete dentin bridge formation and lack of inflammation in the pulp tissue after the application of the MTA (DENTSPLY Tulsa Dental) as a pulp-capping material and after mechanical exposure. In addition, these pulps demonstrate lack of calcific degeneration, which is one of the negative sequelae to calcium hydroxide pulp capping.

No. 2: Hyperemia

Symptom: pain to cold.

Duplicate: apply ice on tooth.

Figure 3a. Clinical Distinction No. 2: Hyperemia. When patients symptom is cold, duplicate with cold. (Courtesy of Dr. Frank Casanova.)
Figure 3b. An ice stick made by freezing water in a sterile dental anesthetic carpule is an inexpensive and accurate cold source to duplicate hyperemia.
Figure 3c. Apply ice to contralateral tooth from suspected source or anterior or posterior to it in order to develop patient cold response baseline before applying ice to most likely candidate.

Hyperemia is a potentially reversible pulp condition (Figures 3a through 3c). Many patients have pain to cold and simply learn to avoid cold to that tooth. When patients forget, they experience intense but fleeting pain to cold. In order to test a hyperemic tooth, a pencil of ice made from a sterile anesthetic carpule is useful because the ice melts into the crack or exposed dentin that is causing the problem. Unlike pulpal ice sprays, the ice melting on the tooth can circumferentially surround it and more easily duplicates the symptom. It is important to test the suspect tooth last so that the clinician can evaluate a baseline in terms of patient response. Some patients are extremely sensitive, and some patients seem to never feel anything. Yet most patients feel varying amounts of cold reaction depending on the tooth. It is important to know how the patient will react to ice, otherwise a tooth may duplicate, but actually it is just a particularly sensitive patient.

The real question is what to do about a tooth that is thermally sensitive to cold. If a defective restoration is present, then it should be restored with an appropriate pulpal protective base. However, according to Susan Carlson, RDH for Dr. Frank Spear (Seattle, Wash), if gingival recession is present, a proven and useful protocol is as follows:

(1) Perform prophylaxis.

(2) Protect (Sunstar Butler).

(3) Omni Gel (Home) 0.4% SnF 2x per day for 2 weeks. Approximately 80% of teeth will be better. If this is not successful, then Durafluor varnish (Pharmascience).

(4) All-Bond, Gluma, or Desense-type pulpal protections.

(5) Perform endodontics if none of the above are successful.

No 3: Pulpitis

Symptom: pain to heat.

Duplicate: heat test.

Figure 4a. Clinical Distinction No. 3: Pulpitis. Heat pain means pulpitis, which means irreversible pulpal inflammation. (Courtesy of Dr. Frank Casanova.)
Figure 4b. Duplicate heat pain using warm gutta-percha applied to different teeth until symptom is duplicated.
Figure 4c. Pulpitic pulps almost always bleed. In multirooted teeth, bleeding usually stops after the chamber pulp is removed followed by sterile pellet and cavit. Schedule endodontic completion; or if time allows endodontics can be finished same day.
Figure 4d. Microscope picture of chamber pulp that has been dissolved in 5.25% sodium hypochlorite. Note one larger and many smaller denticles, any of which could block the root canal system unless treated delicately to be negotiated past and removed. These denticles can easily block a canal if not seen or not treated with great care.

Unlike hyperemia, where the discomfort is immediate, heat pain is paroxysmal, a delayed response that builds and becomes incredibly intense. Often, these patients will present to the clinician with a glass of water to cool the tooth and create comfort. While many people have teeth that are sensitive to cold, teeth are not sensitive to heat unless they are pulpitic (Figures 4a through 4d). This condition will typically only last from 8 to 12 hours or occasionally for a day or 2. Intense pain to heat does not last for weeks or months. Since the heat response is delayed, the heat pulp tester (hot pulp tester; SybronEndo) should be applied to a tooth that is not suspect. It is important to pause for a minute after each test, since the heat response is delayed. When it is clear that heat has not duplicated the symptom for a particular tooth, then the clinician can advance to the next tooth until the symptom is duplicated. The emergency treatment for pulpitis in a multi-rooted tooth is a pulpotomy and in a single-rooted tooth a pulpectomy.

Often, these pulps hemorrhage. In a multirooted tooth, the clinician should clinically avoid the canals unless there is time to clean, shape, and pack because pulps contain many denticles and calcifications that could easily block the canal when a dentist is in a hurry (Figure 4d). Sliding down the root canal system  with files requires extreme delicacy, focus, and a clear intention. Emergency treatment is usually not the time for concentration and ample time for gentleness and patience. The doctor, patient, and tooth would be best served by doing the minimal amount necessary to have the patient arrive in pain  to the office and leave in peace; not the other way around, which is often the result of a messy pulpotomy. While we may eliminate the heat pain for many of these patients, if a pulpotomy on a multirooted tooth is not done correctly, these patients have a constant ache and require cleaning and shaping.

A useful way to perform the pulpotomy for a pulpitic tooth is to use a long shank No. 4 round bur rotating in reverse on each of the orifice openings. Usually, the bleeding will stop, and a sterile cotton pellet is placed, followed by Cavit (3M ESPE) as a temporary material. If, however, one of the pulps continues to bleed, the clinician can advance another half-bud deeper into the orifice. If bleeding still continues, then and only then would it be wise to extirpate that pulp or clean that particular canal. The clean, shape, and pack visit can then be scheduled for another date.

 

 

 

 

 

 

 

 

 

 

No. 4: Necrosis

Symptom: none.

Duplicate: electric pulp test (EPT) and ice test are negative.

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure 5a. Clinical Distinction No. 4: Necrosis. Once the pulp has become necrotic, there is no emergency. Diagnosis is duplicated with pulp tests, and endodontics can be started or started and finished. (Courtesy of Dr. Frank Casanova.) Figure 5b. Pulp testing can occur for teeth that have full coverage by retracting gingival tissue and applying EPT. EPT only measures alive or dead. It does not measure the degree of health in a living pulp.

A necrotic pulp in and of itself cannot be diagnosed on a radiograph until the disease has advanced into the attachment apparatus (Figures 5a through 5b). Often, patients will report they had a toothache last week but that the pain has stopped now. There may even be a sinus tract that could be traced to the source tooth yet still not indicate a lesion of endodontic origin radiographically. The pulp should test nonvital to the electric pulp tester and to ice. If there is any question, a test cavity should be performed under the rubber dam and, of course, without anesthesia to confirm the necrotic pulp. Many necrotic pulps exist undiagnosed. Full-mouth pulp testing should be performed on an annual basis in order to discover these sleeping problems long before they become acute.10

No. 5: Lesion of Endodontic Origin

Symptom: none or percussion; may or may not be swollen.

Duplicate: radiograph reveals a lesion of endodontic origin (LEO), and EPT and ice test are negative. A LEO signifies the first of the 6 distinctions where the pulpal disease has advanced to the periradicular area.

Figure 6a. Clinical Distinction No. 5: Lesion of Endodontic Origin (LEO). Figure 6b. Radiograph of apical and mesial lesions of endodontic origin traced by gutta-percha cones.


Figure 6c. Proper technique for successful electric pulp testing. Be sure to pulp-test a dry surface and pulp-test a natural tooth in the cervical area. Remember, pulp testing does not measure the degree of health; it measures whether the pulp is vital or nonvital.

The presence of a LEO often follows pulpal disease and flows coronal to apical due to lateral foramina or portals of exit (POE) (Figure 6a). Regardless of where a LEO is formed, the clinician always expects an adjacent foramen. Often, a traced sinus tract will lead to a LEO (Figure 6b). The diagnosis is the same as necrosis, which is to duplicate by verifying the pulp is nonvital using the electric pulp tester (Analytic Pulp Tester, SybronEndo).  Electrocardiogram paste makes an excellent conductor. It is essential in both necrosis and teeth with an apparent LEO that the surface of the tooth is dry to avoid a false positive. The pulp-testing position is best in the cervical third of the tooths crown where the enamel is thinner. Using a small electrical pulp tip (SybronEndo) and gingival reflection either with a plastic instrument or periodontal cord, pulps can be tested accurately, even under crowns.

No. 6: Acute Alveolar Abscess

Symptom: tooth hurts to percussion.

Duplicate: patient will point to the tooth; they know which one it is.

Figure 7a. Clinical Distinction No. 6: Acute alveolar abscess (AAA). For the first time in the endodontic disease process, the patient can identify the pain source due to osseous proprioception. (Courtesy of Dr. Frank Casanova.) Figure 7b. After an AAA is accessed, varying amounts of pus usually visually follow. Following water chewing protocol, patient is scheduled for endodontic completion.

The acute alveolar abscess (AAA), for the very first time in the 6 clinical distinctions, can be identified by the patient since bone, unlike the pulp, has proprioception (Figures 7a and 7b). Patients often have a history of all or a combination of the previous 5 distinctions. There may or may not be swelling, and there may or may not be a radiolucency. The pulp tests nonvital to electric pulp tester and ice. A test cavity is negative. Step one in an AAA is to take the tooth out of occlusion. This creates immediate relief and patient confidence. Patient education is key. Ideally, access is made with a rubber dam and without anesthesia. This is to validate the diagnosis, and it also enable you and the patient to know that he or she is better before leaving the office instead of in the evening, perhaps when the patient is home and you are away from the office.

In an AAA, there is almost always some amount of purulent discharge present. The amount of discharge, whether the patient is a particularly sensitive patient and whether you are present in the office in the next couple of days, will determine whether (1) this tooth should be gently irrigated and closed, (2) the patient placed on antibiotics, or (3) the tooth opened for water chewing. Water chewing involves the patient chewing warm salt water for 10 minutes and spitting it into the sink after several chews. It must be distinguished that the patient should not swish‚ the warm salt water, but literally chew up and down as if he or she were chewing vertically. The mandible should go up and down in a vertical motion. Patients should water chew until they feel 100% better or close to it before leaving the office. If they say that they are 50% better after 10 minutes, have them water chew until they are 75% better. When they say they are 75% better, have them water chew until they are 100% better! Almost always, patients will experience extraordinary relief, and you can schedule the endodontic finish at another time when the patient is asymptomatic, usually within a day or 2.

These teeth are left open for less than 3 weeks. The historical problem for dentists and patients with closing these teeth has been that often they would swell again. We now know this is due to improper irrigation, cleaning, and shaping. With newer technologies such as nickel titanium shaping and better irrigation efficacy with sodium hypochlorite and 17% aqueous EDTA, along with hydrogen peroxide and newer irrigants soon coming to market (such as MTAD,  DENTSPLY Tulsa Dental), we can effectively kill bacteria within the root canal system, clean and shape, and eventually successfully obturate. Once the patient is comfortable, he or she is given the water chew instructions, which are as follows:

(1) Water chew for 5 minutes of every hour until you are better.

(2) Water chew at the end of each meal and spit or swallow.

(3) Chew food on the opposite side.

(4) Do not use a toothpick or a Waterpik in the access of your tooth.

(5) Call the office tomorrow and report progress.

The immediate relief of your bone ache is directly proportional to your strict adherence to items 1 through 3. Although this regimen may inconvenience you somewhat, the relief and the saving of your tooth will justify following these important instructions.

12 Clinical Tests

The following tests are well known by dentists, but many times clinicians forget 1 or 2 of them. For example, palpation and percussion are very useful, a wet cotton roll can be extremely diagnostic, transillumination can be  helpful in discovering hairline fractures, and the periodontal probe is a must for every tooth of a patient who presents with endodontic pain. The majority of the 6 clinical distinctions can be duplicated and confirmed using these tests: (1) radiograph; (2) palpation; (3) percussion; (4) cold; (5) hot; (6) electric pulp test; (7) wet cotton roll test; (8) test cavity; (9) anesthesia; (10) transillumination; (11) staining; and (12) periodontal probe.

The only conditions that this article really has not addressed are first, the cracked tooth syndrome.11 In this situation, there is pain to bite yet the pulp is vital. If we remember that pulps die in a coronal to apical direction, then this symptom does not make sense. However, it makes total sense in the cracked tooth syndrome,  where the bite pain is not because of periradicular disease but rather due to the influence of the hairline crack on dentin and pulp continuum.

The second condition that does not fit these clinical distinctions is when a pulp does not have a symptom to duplicate. The patient simply presents with apparent pulpal pain. It does not hurt to cold. It does not hurt to heat. It does not hurt to bite. It does not hurt to percussion. It just hurts. This condition, if pulpal, will not last for more than a day or 2. The anesthetic test can sometimes pinpoint this tooth or at least several possible teeth. The Stabident (Fairfax Dental) in the osseous system is useful in isolating the tooth or reducing the possible pain source down to 2 teeth. If not, in the case of mandibular toothache, a mental local anesthetic injection can be given. If pain is still present and 2 molars are present, the clinician can administer a mandibular block. If the pain is gone, then one of those 2 molars is suspect. Anesthetize the patient with a long-acting anesthetic such as marcaine and have him or her return when the anesthesia dissipates. Often the symptoms will have changed. The toothache will be milder or gone, in which case the pulp is necrotic. That is an easy distinction to duplicate. The disease will immediately progress to an acute alveolar abscess, and again this symptom is easy to duplicate. If the patient‚s tooth has not passed into either of these distinctions, then administer a second long-acting block and repeat the assessment when the anesthesia has discontinued after several hours. Perhaps an analgesic would also help buy some time until the pulp changes its condition. Fortunately, patients do not have these severe toothaches for days or weeks on end. The pulp will become necrotic soon, create a LEO, or develop an AAA-any of which are easy to diagnose.

The key is to listen to the patient, then duplicate the symptoms the patient is having today. The 6 clinical distinctions described take the subjectivity out of endodontic diagnosis. The diagnosis is basically blamed onto the tests, which leads to the correct distinction, then proper treatment. If patients ask the clinician what does the dentist think the clinicians response should be that the tests say this is the diagnosis. It is very objective's no emotion! You can proceed with confidence that the diagnosis is accurate, and the emergency treatment will be successful.

SUMMARY

Review of 6 clinical distinctions:

(1) Symptom: anything under the sun.

Diagnosis: pulp exposure.

Duplicate: clinical or radiographic pulp exposure evidence.

Treatment: endodontics or pulp cap under strict protocol conditions.

(2) Symptom:

Diagnosis: hyperemia.

Duplicate: ice.

Treatment: pulp protection or endodontics.

(3) Symptom: heat.

Diagnosis: pulpitis.

Duplicate: heat.

Treatment: pulpotomy for multirooted teeth or  pulpectomy for single-rooted teeth. Schedule endodontic completion.

(4) Symptom: I recently had a toothache and now it is gone.

Diagnosis: necrosis.

Duplicate: Electric Pulp Test and ice are negative.

Treatment: endodontics.

(5) Symptom: I had a toothache awhile back and now it is gone

Diagnosis: LEO.

Duplicate: Electric Pulp Test, ice, and test cavity are negative.

Treatment: endodontics.

(6) Symptom: It really hurts to touch my tooth.

Diagnosis: percussion.

Duplicate: may or may not have a LEO and may or may not have cellulitis.

Treatment: reduce occlusion, access cavity, water chew, and schedule to finish endodontics.

If these tests are carefully performed, then they are objective and the doctor does not have to be in a subjective situation. A newfound sense of endodontic diagnostic mastery is experienced.

Perhaps the best way to summarize the simplicity of this clinical diagnostic scheme is to quote Sherlock Holmes: Nothing is more deceptive than the obvious.


References

1. Ingle JI, et al. Endodontic diagnostic procedures. In: Ingle JI, Bakland LK, eds. Endodontics. 5th ed. Hamilton, Ontario, Canada: BC Decker; 2002:203-258.

2. Cohen S. Diagnostic procedures. In: Cohen S, Burns RC, eds. Pathways of the Pulp. 7th ed. St Louis, Mo: Mosby; 1998:1-19.

3. Bender IB, Seltzer S. Roentgenographic and direct o

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