After reading this chapter, the student should be able to:
Recognize that diagnosis and treatment planning for pulpal and periapical conditions should be part of a broader examination and treatment plan.
Understand the importance of the medical and dental histories to endodontic diagnosis.
Conduct comprehensive extraoral and intraoral examinations of both hard and soft tissues, including the application of pulp sensitivity tests.
Develop the knowledge base to order and interpret appropriate diagnostic radiographs.
Consolidate all data from the history, clinical examination, and radiographic examination to form a diagnosis of pulpal and periapical conditions using appropriate terminology.
Diagnose adjunctive conditions to the typical endodontic diagnosis, including resorption, fractures, and endodontic–periodontic interrelationships.
Recognize when orofacial pain and infections are not of endodontic origin.
Identify conditions for which root canal treatment is indicated and contraindicated; understand alternative treatments.
Integrate the endodontic diagnosis and treatment plan into an overall treatment plan.
Understand which procedures are ordinarily not within the graduating dentist’s realm of training or experience and which patients should be considered for referral.
Accurate diagnosis is paramount to appropriate care. Endodontic diagnosis and treatment planning generally occur in two basic scenarios. In the first scenario, the emergency patient presents with pain and possibly swelling, or with a displaced, fractured, or avulsed tooth. In the second, pulpal or periapical disease is detected incidentally; endodontic care is expected. Emergency situations demand an accurate and timely diagnosis. Missteps in diagnosis will result in continued morbidity. Errors in diagnosis may result in the addition of unnecessary treatment with increased cost and suffering for the patient ( Fig. 4.1 ), In the short term, misdiagnosis can result in unsatisfied patients and clinical frustration for the provider. In the long term, uncontrolled infections may have serious consequences to systemic health and affect the prognosis of future treatments.
Even nonemergent situations require care in confirming the appropriate diagnosis, because nuances to the diagnosis can render traditional nonsurgical root canal therapy ineffective. For example, a tooth that has developed pulpal and periapical pathosis secondary to a coronal fracture with root involvement might not survive in the long term after endodontic therapy. Additionally, other normal and pathological entities can mimic endodontic pathosis; these entities are discussed in Chapter 5 .
Diagnosis is the science of recognizing and identifying disease by means of signs, symptoms, and tests. The basic elements of diagnosis are data gathering and analysis to develop a differential diagnosis, a definitive diagnosis, and a treatment plan. This chapter will focus on the appropriate means to obtain an accurate endodontic diagnosis, including the specifics of the examination process, the appropriate terminology to describe endodontic pathosis, and a discussion of definitive care to be delivered based on the findings and their interpretation ( ).
The chief complaint is the first verbal information from the patient. The chief complaint is often volunteered without a question and is recorded in the patient’s own words. Close attention is paid to this statement.
Dental history is divided into the present dental illness, also referred to as the history of the chief complaint, and the past dental history. Once the patient has described why he or she is seeking care, details are established by methodical questioning. There are a limited number of complaints of endodontic consequence. If there are two or more concurrent complaints, such as pain and swelling, then the history of each complaint should be obtained.
Beyond gathering a list of reported symptoms, questions are asked regarding their timeline and quality. As pain is the most common reason for seeking endodontic care, this symptom is questioned directly. Some patients supply a detailed history of pain; others require guidance to determine the location, onset, duration, quality, intensity, and exacerbating or relieving factors. Directive questions should be open-ended when possible to avoid any influence on the patient’s answers. In the early stages of a pulpitis, pain may be difficult to localize, thus nonlocalizable pain raises suspicion. Certain referral patterns of odontogenic pain are common, such as pain from a pulpitis in a mandibular molar commonly referring to the ear. Similarly, certain referral patterns for nonodontogenic pain are common and will be discussed in Chapter 5 . Examples of questions to obtain a detailed history of the chief complaint are in Table 4.1 ( ) .
|Location||Where is the pain located?
Is it always in the same spot?
|Onset||When did your symptoms start?
Did or does anything initiate the pain?
|Duration||When you have pain, how long does it last?
When did your symptoms last occur? Is the pain continuous or intermittent?
|Quality||How would you describe your pain? (For example, dull/achy or sharp/electrical)|
|Intensity||On a 0–10 scale, where would you rate your pain at its worst?|
|Exacerbating factors||Does anything make your pain worse? (For example, cold, heat, or biting.)|
|Relieving factors||Does anything make your pain better? (For example, cold, pressure, or analgesics.)|
Patients will often falsely report presence or a history of swelling. True swelling must be associated with pulp necrosis, though patients may perceive swelling even with symptomatic irreversible pulpitis.
Although localized acute apical abscesses do not associate with systemic symptoms, endodontic infections rarely can spread with serious sequelae. Patients with swelling require further questioning about the onset and duration, changes over time, and effects on jaw opening, swallowing, or breathing. Although rare, any rapidly progressive swelling, accompanied by trismus, dysphagia, or dyspnea is considered a progressive cellulitis (space infection) necessitating prompt referral to an oral surgeon or hospital for intravenous antibiotics and probable extraoral incision and drainage. The nature of the swelling, whether indurated or soft, and associated drainage may be reported by the patient. With cellulitis, the patient should also be examined for signs of systemic involvement such as fever, malaise, or lymphadenopathy, all of which might prompt the use of systemic antibiotics. , More information on dental emergencies and indications and contraindications for systemic antibiotics are in Chapter 9 .
Traumatic dental injuries require their own workup, including an assessment for comorbid injuries, such as concussion, jaw fractures, soft-tissue lacerations, or involvement of other teeth, as well as lapses in tetanus immunity. More information specific to the workup related to traumatic dental injuries is in Chapter 11 .
Patients presenting with endodontic pathosis will usually have a history of dental procedures. Prior pain is even considered a risk factor for current endodontic pathosis. Patients are asked about overall oral health, including recent dental procedures, a history of trauma, and previous issues with temporomandibular dysfunction. Patients may report cracks or fractures that prompted prior restorative care. Other findings during the objective portion of the examination prompt further questioning. For example, if soft-tissue scarring is seen, a patient may be asked about a history of oral surgical care.
An updated picture of the patient’s health is obtained at each visit, including a complete medical history, list of active medical issues, medications, and allergies.
Certain health issues are of concern in endodontic diagnosis. For example, acute respiratory infections, particularly of the maxillary sinus, often produce toothache-like symptoms. Pain-modulating conditions, such as fibromyalgia, may have atypical pain presentations. Treatment options may be affected. Bisphosphonates, biologics, and chemotherapy agents are associated with osteonecrosis of the jaw and can limit a patient’s options for surgical or extraction alternatives in favor of root canal therapy. Radiation therapy to the head and neck limits these more invasive treatment options due to risks of osteoradionecrosis.
A complete list of medications and allergies is needed to ensure that drug interactions and adverse events will not occur during treatment. The need for antibiotic prophylaxis related to cardiac conditions, prosthetic joints, and certain immune deficiencies are considered. A comprehensive review of medical conditions that can affect endodontic care, as well as discussion of antibiotic prophylaxis, are in Chapter 2 . Whenever doubt exists as to limitations for care or the need to premedicate, consultation should be had with the patient’s treating physicians.
Vital signs, including blood pressure, respiratory rate, and pulse, should be obtained as part of the examination process. In addition, in patients reporting swelling or signs and symptoms of infection, including suspected fever, malaise, or lymphadenopathy, an oral temperature reading should be taken.
General appearance, skin tone, facial asymmetry, swelling, discoloration, redness, extraoral scars or sinus tracts, and lymphadenopathy are indicators of the physical status of the patient. Aberrant findings are suggestive of related orofacial infections or inflammation ( Fig. 4.2 ; ).
Examination of the intraoral soft tissues includes a thorough visual, digital, and probing examination of the lips, oral mucosa, cheeks, tongue, palate, muscles, and periodontium for abnormalities. Particular focus should be paid to the alveolar mucosa and attached gingiva adjacent to a suspicious tooth for the presence of discoloration, inflammation, ulceration, and sinus tract formation. A stoma or parulis is the visible point of drainage of a sinus tract, and usually indicates the presence of a necrotic pulp and chronic apical abscess ( Fig. 4.3 ). Sinus tracts may also occur secondary to nonendodontic pathology such as a periodontal abscess, vertical root fracture (VRF), or even osteomyelitis; thus, the source of drainage should always be determined. Sinus tracts may be traced radiographically with gutta-percha, or cone beam computed tomography (CBCT) imaging may show their point of origin.
A limited periodontal examination should occur as part of any endodontic workup. Periodontal probing depths should be measured, because localized attachment loss can indicate not only the presence of periodontal disease that might affect the overall prognosis and affect treatment planning but can also suggest the presence of additional pathology. Fractures, whether originating coronally, or involving root structure, may present with localized deeper probing depths when a root is involved. Endodontic–periodontic lesions will typically present with a wider area of attachment loss ( Fig. 4.4 ; ).
Mobility should be measured, as extreme mobility usually indicates limited periodontal support or an underlying root fracture. In addition, a periapical lesion may occasionally alter the periodontal support; mobility should decrease dramatically after successful root canal treatment (Video 5.4 ).
A visual examination assesses for discolorations, fractures, abrasion, erosion, caries, defective restorations, or other abnormalities. Use of a pointed explorer can help detect caries, failing restorative margins, and sometimes subgingival root resorption. A discolored crown is often pathognomonic of pulpal pathosis or may be the sequela of earlier root canal treatment. The most common etiologies of pulpal involvement are caries, fractures, or historically deep restorations; a visual examination will help elicit the cause of pathosis. Teeth that lack extensive restorations, or have small, class 1 nonbonded restorations in place, may suffer from pulpitis secondary to marginal ridge fractures extending deep into pulp or even root structure. ,
Objective tests are applied to both suspect and control teeth. These tests have limitations; some cannot be used on each tooth, and results are often inconclusive. The data they provide must be interpreted carefully and in conjunction with all other information available. Importantly, these are not tests of teeth; they are tests of a patient’s response to a variety of applied stimuli, which may be highly variable. Tests on control teeth educate the patient on which response to expect and provide a “calibrated” baseline for responses on suspect teeth ( ).
Periodontal Inflammation Tests
Percussion, palpation, and bite testing can detect inflammation of the periodontium. Percussion testing is commonly performed by tapping on the incisal or occlusal surface of the tooth, with the end of a mirror handle parallel or perpendicular to the crown. This test is preceded by gentle digital pressure to detect teeth that are very tender and should not be tapped with the mirror handle, which could be very painful. ( )
Palpation testing is performed by application of firm fingertip pressure on the buccal or facial mucosa overlying the apex. Palpation testing additionally allows for careful detection of intraoral swelling or bony expansion. When pain on chewing is reported, bite testing should replicate symptoms. Bite testers include cotton rolls, cotton swabs, or commercially available plastic testers that can isolate individual cusps ( Fig. 4.5 ; ).
If a marked painful response is elicited, some degree of periapical inflammation is assumed. Pain on biting can also indicate the presence of a coronal fracture, possibly hidden beneath a large occlusal restoration. Often, teeth adjacent to the diseased tooth may be tender because of the local spread of cytokines and neuropeptides that lower the pain threshold. Periapical inflammation may also be nonendodontic, due to traumatic dental injuries, occlusal trauma, or periodontal disease.
Pulp Sensitivity Tests
Determination of the vitality status of the pulp, whether normal, pulpitis, or pulpal necrosis, is critical. Absolute measures of pulp vitality are not yet clinically accurate. Measures to detect vascular components using beams of light in dual wavelength spectrophotometry, pulse oximetry, or laser Doppler flowmetry are, however, on the horizon. Currently, these approaches are more experimental than clinically practical, and the devices are expensive. As the technology improves and cost decreases, their use in the future is likely.
Until then, conduit measures of pulp sensitivity via nervous system response and replication of symptoms include thermal, direct dentin, and electric stimuli. Though no currently available test reflects the true histologic status of the pulp with absolute accuracy, reasonable agreement occurs. ,
All tests are subject to errors and false responses, and certain teeth cannot be tested by all means. For example, immature teeth lack fully developed Aδ fibers, which are the responding fibers in currently available pulp sensitivity tests; thus, testing is unreliable until full root maturation occurs. The choice of which test to use should factor in reliability as well as the presenting chief complaint. All aspects of the clinical and radiographic examination are assessed to define a pulpal diagnosis. The definitive diagnosis might change when the pulp is accessed and visualized.
Although no currently available test has absolute accuracy, cold testing is considered the most reliable measure. Often, cold sensitivity is the chief complaint of a painful pulpitis, and replication of symptoms will point to the offending tooth. Although alternative means exist for cold testing, including the use of ice sticks, carbon dioxide, or dry ice, refrigerant sprays are considered the most convenient and reliable means of cold testing. , Additionally, refrigerant sprays provide the most accurate results in testing through porcelain-fused-to-metal restorations ( Fig. 4.6 ; ).
Cold testing relies on outward hydrodynamic fluid flow to stimulate Aδ fibers in the pulp. Because inflammation associated with pulpitis can cause both allodynia and hyperalgesia of these fibers, the cold response may be heightened. A normal cold response is typically sharp and quick but should be comparable to responses for adjacent and contralateral control teeth. A heightened and lingering response to cold is very suggestive of symptomatic irreversible pulpitis. No response usually suggests pulpal necrosis.
A false-negative response is common when cold is applied to teeth with calcific metamorphosis presumably due to reduction in hydrodynamic fluid flow. A false-positive response may result if cold contacts gingiva or is transferred to adjacent teeth with vital pulps. Surprisingly, gingival recession and attachment loss decrease the sensitivity to cold testing.
Heat testing is reserved for use when the chief complaint includes heat sensitivity; results are less reliable than cold and electric pulp testing (EPT). Various techniques and materials can be used. Heated gutta-percha applied directly to the buccal or facial crown surface, either by use of a Bunsen burner or a commercially available welled tip for a System B device, can be utilized. Use of a dry rubber prophy cup rotated on the surface of a tooth to create frictional heat is a safe alternative ( Fig. 4.7 ). Heated metal instruments or hot water can be damaging to the dental pulp and their use should be avoided ( ).
Like cold testing, heat testing relies on hydrodynamic fluid flow causing Aδ fiber stimulation, this time in a pulpward direction away from the stimulus. As with cold, a sharp and nonlingering pain response to heat indicates a vital pulp; however, false negatives are common. Heat responses may occur in previously treated teeth as a result of untreated anatomy. Diagnostic heat testing usually results in replication of the pain and corresponds to a diagnosis of symptomatic irreversible pulpitis.
Electric Pulp Testing
EPT is a useful adjunct. It is less accurate than cold testing and does not differentiate between normal pulp and that with a pulpitis. All electrical pulp testers are used in a similar manner. It is important to clean, dry, and isolate the teeth. The surface is scrubbed with a cotton roll, isolated with the same roll, and dried thoroughly with the air syringe. A small amount of toothpaste is placed on the electrode. The electrical circuit is completed by using a lip clip or having the patient touch the metal handle. The electrode is placed on the facial or lingual surface of enamel or dentin ( Fig. 4.8 ), and the level of current is gradually increased until a response is reported by the patient. ( )
Electric pulp testers cannot contact composites or metallic restorations, including crowns.
EPT produces a high-frequency electric current that creates ionic changes in dentinal fluid, which stimulates the Aδ fibers in the pulp. Because it does not rely on the hydrodynamic fluid flow of the thermal tests, EPT may be more accurate with calcific metamorphosis. High readings tend to indicate necrosis. Low readings indicate vitality. Testing normal control teeth establishes the approximate boundary between the two conditions. The exact number of the reading is of no significance and does not detect subtle degrees of vitality, nor can EPT indicate inflammation.
Usually, this sequence of subjective and objective testing together with the radiographic examination will allow for accurate diagnosis. Occasionally, inconsistent findings will be found, or the question will remain as to whether endodontic pathosis is indeed present. Dentin stimulation (the stimulating of dentin without anesthesia) is often applied when traditional pulp sensitivity tests are inconclusive. A test cavity (or scratching exposed dentin or cementum) producing sensitivity is an indicator of pulp vitality. Several adjunctive means of examination are available, including caries removal, selective anesthesia, transillumination, and staining ( ).
Determination of the depth of caries is often necessary to make a definitive pulpal diagnosis, particularly in asymptomatic cases with deep decay as seen on a radiograph. A soft carious pulp exposure after complete excavation of caries, in an otherwise asymptomatic tooth with normal responses to clinical testing, is asymptomatic irreversible pulpitis.
The use of local anesthetic to selectively anesthetize and narrow the focus of pain can be especially helpful when a patient cannot identify the offending tooth. When aiming to determine whether a pain source is maxillary or mandibular in origin, the maxilla is generally anesthetized first using local infiltration. The technique should begin with anesthesia in the mesial most suspected location, working distally as needed to broaden the scope of anesthetized tissues. If maxillary teeth have been ruled out, then mandibular techniques, again moving mesially to distally, can be used, with administration of block anesthesia as the last line in the anesthesia of posterior mandibular teeth. Periodontal ligament (PDL) injections will often anesthetize several teeth and are not considered useful for this purpose.
Radiographs detect carious lesions, defective restorations, previous root canal treatments, abnormal pulpal and periapical appearances, impacted teeth, the relationship among teeth and the adjacent neurovascular bundle and maxillary sinuses, and bone loss from periodontal disease. They may also reveal structural changes and bony disease unrelated to the pulp ( Fig. 4.9 ).
Selection of Appropriate Imaging Modality
A high-quality, properly aligned periapical image is essential. Bitewing radiographs are helpful in the determination of bone heights when considering restorability and when evaluating for caries depth, restoration integrity, occlusion, and periodontal health.
Although not yet the standard of care, CBCT imaging has increasingly become routine. CBCT imaging eliminates the anatomic noise that limits two-dimensional imaging, particularly in areas of structural overlap, such as the maxillary posterior. CBCT images can detect periapical pathosis in an earlier stage of disease than can two-dimensional imaging techniques (see Chapter 3 ). As extraoral images, they can be readily used when otherwise limited by oral structures or a prominent gag reflex. CBCT imaging does, however, have disadvantages, including increased radiation exposure, as well as cost and availability. Images require a longer duration of time that a patient must be still, which can itself be a limiting factor.
CBCT imaging should be considered as an aid in difficult diagnoses, such as when there are contradictory clinical signs and symptoms, as a treatment aid related to complex anatomy, in previously endodontically treated teeth to assess for untreated anatomy, in evaluating for prior treatment complications, in assessing potential surgical cases, and in the workup of cases of trauma or resorption.
Periapical inflammation results in bone resorption and the resultant periapical radiolucency. Although small radiolucent lesions may be present with irreversible pulpitis, especially with the sensitive images of CBCT, a sizable radiolucency with a vital pulp is not endodontic. It is impossible to determine whether a lesion is cystic by radiographs alone; rather, surgical access, biopsy, and histologic analysis are necessary for identifying the true nature of pathosis.
Periapical lesions of endodontic origin generally have the following four radiographic characteristics:
The lamina dura is absent apically.
The radiolucency remains at the apex in radiographs made at different cone angles, as well as on CBCT imaging.
The radiolucency resembles a hanging drop.
There is an identifiable etiology that caused the pulpal necrosis.
Radiopaque changes can also occur. Condensing osteitis is a reaction to pulpal or periapical inflammation and results in adjacent increased density of trabecular bone, presenting as a diffuse circumferential medullary pattern with indistinct borders ( Fig. 4.10 ). It is differentiated from the well-circumscribed, more homogeneous enostosis or sclerotic bone commonly found in the mandibular posterior region, and other nonendodontic radiopacities associated with the roots of teeth with normal pulp tissue.
Radiographs are often the only means to detect root resorption. External root resorption, including apical, lateral, and invasive cervical forms, can be detected by changes in root size and shape. CBCT imaging is essential to determine the nature and location these lesions.
Careful visualization of the pulpal space allows for detection of pathologic and nonpathologic conditions. Extensive diffuse calcification in the chamber, or pulp canal obliteration, may indicate long-term, low-grade irritation related to deep restorative treatment or trauma and is not usually pathologic. Pulp stones are discrete calcified bodies found in pulp chambers and are sometimes visible on radiographs. They are not considered pathologic, but they have been associated with cardiovascular disease, gout, hypercalcemia, end-stage renal disease, dentinogenesis imperfecta, and certain medications, including statins and corticosteroids.
Internal root resorption is an abnormally altered pulp space enlargement due to localized pulpal inflammation with resultant dentinoclastic activity, , ( Fig. 4.11 ). As in external resorption, CBCT imaging can determine the location and extent of these lesions.