Diagnostic AidsThe location and diagnosis of dental pain is at least as important as the endodontic treatment itself. You may choose never to perform endodontic procedures after graduation, however, the understanding and diagnosis of dental pain will be a most important part of your armamentarium throughout your dental careers, regardless of what paths you travel. Our diagnostic techniques are designed to distinguish dental pain from pain of non-odontogenic origin (sinus infection, tumors, etc.), and then within the realm of dental pain, to locate the offending tooth and determine if the problem is pulpal or periodontal. (See clinical diagnoses chart for more information on specific diagnoses.) The endodontic chart lists the different categories in the progression of pulpal degeneration:
It is easier to understand the use of the diagnostic aids by drawing an imaginary line between "Irreversible pulp inflammation" and "Necrotic pulp". This line divides vital from nonvital and is a most important distinction because it helps locate the offending tooth and dictates the treatment approach. "Vital" (above the line) indicates that there are still nerves and blood supply to the pulp and although the inflammation may be acute, the noxious stimuli (bacteria, toxins, etc.) are still being contained. On the other hand, once the pulp becomes necrotic (below the line), infection has gained a foothold. Let us now consider these diagnostic aids that help us decide which tooth is causing pain, whether the pain is pulpal and finally help us make an intelligent judgment as to the status of the pulp (vital vs. nonvital). 1. History of the sequence of symptoms is of paramount importance. Because the pulp is, at any given moment, a cumulative record of all the traumas that the tooth has endured throughout its life, be they bacterial, iatrogenic, physiologic, etc., it is essential to listen to the patient's story. The endodontic chart lists some of the items to ask and look for. When taking a patient's history it is wise to begin with the chief complaint and then proceed to the general history when the patient has told you why he/she wants treatment. Inflammatory reactions in the pulp and periapical tissues can give pain. However, so can periodontitis, pericoronitis, maxillary sinusitis, herpes zoster, craniomandibular disorders, some neurologic and cardiovascular disorders, and other processes. All these can be experienced as "toothache" by the patient. The examination of the patient makes it possible to find out which disease is the cause of the patient's symptoms. 2. Electric Pulp Testing measures the sensory nerve response to an electric current that is passed through the tooth and generally indicates pulp vitality. It is always important to test the adjacent and contralateral tooth as a control. Unless the tooth in question is recently erupted or recently traumatized (these 2 situations often give false negative readings), a negative response suggests a necrotic pulp. On the other hand, a positive response indicates vitality. With multirooted teeth a positive response is less accurate because vital tissue in one root may be giving the positive response while the other roots could have necrotic pulp tissue. Teeth that are covered by metal restorations with no exposed enamel cannot be tested with the electric pulp tester unless test cavities are made into natural tooth structure. 3. Thermal Tests are very effective in determining whether a vital tooth is undergoing a pulpitis. Ice (or Ethyl chloride) or heated gutta percha can be applied to individual teeth. By comparing the quality and quantity of the response in testing a quadrant of teeth, one can determine which tooth is causing the patient pain. When the pain lingers after the stimulus is removed, one must suspect a pulpitis. In addition, such teeth are usually hypersensitive to thermal testing and react more strongly. 4. Percussion with the finger and proceeding with the handle of an instrument applied to teeth in a vertical direction and later laterally, will elicit pain when inflammation is spreading into the apical periodontal ligament. Biting on a tooth may still fall into the "vital" category, but not necessarily. Teeth with this response must also be carefully examined for fractures. 5. Palpation. Running your finger over the apices of the teeth in the mucobuccal fold area, as well as on the lingual aspect, will evince pain when the inflammatory process in the pulp has progressed beyond the apex and has caused periapical pathology. The pulp at this stage is generally non-vital and treated as such. This can be a most effective test when a quadrant is bridged, making the percussion test ineffective. 6. Periodontal Probing is an important element in helping you reach a diagnosis. By carefully probing the pockets of teeth with pain or swelling in the gingiva, one can be assured that the problem is pulpal if the probe does not easily slide into the area of pain or swelling. A swelling of periodontal origin would have some communication from the gingival sulcus. 7. Anesthetic Test. Because dental pain is commonly referred to the opposing arch or a nearby tooth, local anesthesia is given at times to localize the pain. If pain persists after the anesthetic has blocked sensation from an area suspected of pain, one can assume the pain was referred to this area, and should look elsewhere for the primary source of pain. 8. Radiographs are a most important diagnostic tool, however, they can be misleading since they are a two dimensional representation of a three dimensional problem. A periapical lesion that has not encroached on the cortical plate, for example, may not show up on an X-ray. Depending on the angulation of any given X-ray, anatomical structures may appear as periapical pathosis. The entire tooth must be examined in a radiograph looking for coronal lesions (caries), apical lesions, periodontal lesions, and intrapulpal pathology (calcifications or resorptive areas). Only with X-rays can we effectively perform endodontic therapy because this is how we determine the number of roots, angulations, root length, calcifications, etc. Invariably, a periapical radiolucency with a break in the lamina dura indicates a non-vital tooth, easily corroborated by the other tests above. If such a tooth were to test vital, the dentist would have to suspect a cementoma, or cyst, tumor, or lesion of non-odontogenic origin. These eight diagnostic aids will be discussed in class session at greater length. It is only with the proper understanding and application of them that you will be able to make accurate and scientific diagnostic judgments throughout your dental careers. |