Establishing an accurate diagnosis of pulpal and periapical conditions is the cornerstone of effective endodontic treatment. Historically, the landscape of endodontic diagnosis has been clouded by classifications rooted in histopathology rather than practical clinical findings, leading to confusion and misinterpretations. A clear, clinically-focused diagnostic system is essential not only for determining the appropriate treatment strategy but also for fostering effective communication among dental professionals, educators, and students. Misdiagnosis can lead to detrimental outcomes, from unnecessary procedures to inadequate treatment, underscoring the critical need for a standardized and reliable approach.
In a landmark effort to address these challenges, the American Association of Endodontists (AAE) convened a consensus conference in 2008. This initiative aimed to standardize endodontic diagnostic terminology, fostering a universal understanding across the dental field. The goals were to propose universally accepted diagnostic recommendations and to develop standardized definitions for key terms, applicable to endodontists, general dentists, educators, and researchers alike. The AAE and the American Board of Endodontics have since endorsed these terms, advocating for their widespread adoption throughout all dental disciplines and healthcare professions.
This article serves as a comprehensive guide to these standardized diagnostic terms. We will define each term, detail the typical clinical and radiographic characteristics of each condition, and provide illustrative case examples to enhance understanding. It is crucial for clinicians to remember that pulpal and periapical diseases are dynamic and progressive. Signs and symptoms can vary depending on the stage of the disease and individual patient factors. Furthermore, the inherent limitations of current pulp testing methods and clinical examination techniques must be considered. Therefore, a complete and accurate endodontic diagnosis necessitates a thorough evaluation of both the pulpal and periapical status of each tooth. To aid in this process, we will introduce an Endodontic Diagnosis Table summarizing key diagnostic points for quick reference and enhanced clinical decision-making.
Dental Examination Tools
Examination and Diagnostic Procedures: Piecing Together the Puzzle
Endodontic diagnosis is not about isolating a single symptom; it is a comprehensive process of gathering and interpreting multiple pieces of information, much like assembling a jigsaw puzzle. A definitive diagnosis cannot be formed from just one finding. Clinicians must adopt a systematic approach, meticulously collecting all necessary data to arrive at a “probable” diagnosis. The diagnostic journey begins with a thorough medical and dental history. This initial step allows the clinician to start formulating a preliminary, logical diagnosis, particularly if the patient presents with a chief complaint. Subsequently, clinical and radiographic examinations, combined with a detailed periodontal evaluation and specific clinical tests (such as pulp and periapical tests), serve to confirm or refine the preliminary diagnosis.
However, it is important to acknowledge that clinical and radiographic findings can sometimes be inconclusive or even contradictory. In such instances, reaching a definitive pulpal and periapical diagnosis may not be immediately possible. It is paramount to emphasize that treatment should never be initiated without a diagnosis. In cases of diagnostic uncertainty, it is prudent to either schedule the patient for reassessment at a later date or refer them to an endodontist for specialized evaluation.
Diagnostic Terminology: Standardized by the AAE and American Board of Endodontics
The following sections detail the standardized diagnostic terminology approved by the American Association of Endodontists and American Board of Endodontics, providing a clear framework for understanding pulpal and periapical conditions.
Pulpal Diagnoses: Understanding Pulp Status
Normal Pulp: This clinical diagnostic category describes a pulp that is symptom-free and responds normally to pulp testing. While histologically the pulp might not be perfectly normal, a “clinically” normal pulp exhibits a mild, transient response to thermal (cold) testing, lasting no more than one to two seconds after removing the stimulus. Crucially, diagnosis always involves comparison with adjacent and contralateral teeth. Testing these teeth first establishes a baseline for the patient’s normal response to cold, facilitating accurate assessment of the tooth in question.
Reversible Pulpitis: This diagnosis is based on subjective and objective findings indicating that the pulpal inflammation is mild and should resolve, with the pulp returning to its normal state once the causative factor is addressed. Patients typically experience discomfort when a stimulus like cold or sweetness is applied, but the pain subsides within seconds after stimulus removal. Common causes include exposed dentin (dentinal sensitivity), dental caries, or deep restorations. Radiographically, there are no significant changes in the periapical region of the affected tooth, and the pain is not spontaneous. After managing the cause (e.g., caries removal and restoration, or covering exposed dentin), the tooth requires re-evaluation to confirm the pulp has returned to a normal status. It’s worth noting that while dentinal sensitivity itself isn’t an inflammatory process, its symptoms closely mimic those of reversible pulpitis.
Symptomatic Irreversible Pulpitis: This diagnosis is made when subjective and objective findings indicate that the vital, inflamed pulp is incapable of healing, necessitating root canal treatment. Characteristics may include sharp pain upon thermal stimulation, lingering pain (often lasting 30 seconds or longer after stimulus removal), spontaneous pain (unprovoked), and referred pain. Pain may be exacerbated by postural changes, such as lying down or bending over. Over-the-counter analgesics are typically ineffective in alleviating the pain. Common causes include deep caries, extensive restorations, or fractures exposing the pulp. Diagnosing teeth with symptomatic irreversible pulpitis can be challenging because the inflammation might not yet have extended to the periapical tissues, meaning there might be no pain on percussion. In these cases, the patient’s dental history and thermal testing are paramount for assessing pulp status.
Asymptomatic Irreversible Pulpitis: This clinical diagnosis is based on subjective and objective findings indicating a vital, inflamed pulp that cannot heal, requiring root canal treatment, but without clinical symptoms. These cases usually respond normally to thermal testing but may have a history of trauma or deep caries that would likely lead to pulp exposure upon removal.
Pulp Necrosis: This diagnostic category indicates the death of the dental pulp, necessitating root canal treatment. The pulp is unresponsive to pulp testing and is typically asymptomatic in itself. Pulp necrosis alone does not cause apical periodontitis (e.g., pain to percussion or radiographic evidence of bone breakdown) unless the root canal system becomes infected. However, it is important to consider that some teeth might be nonresponsive to pulp testing due to calcification, recent trauma, or simply a non-responsive state. This underscores the importance of comparative testing with adjacent and contralateral teeth. A patient may exhibit a generalized non-responsiveness to thermal testing across all teeth.
Previously Treated: This category denotes a tooth that has already undergone endodontic treatment, with the canals obturated with filling materials (other than intracanal medicaments). These teeth typically do not respond to thermal or electric pulp testing.
Previously Initiated Therapy: This diagnostic category indicates that the tooth has received partial endodontic therapy, such as a pulpotomy or pulpectomy. Depending on the extent of the previous treatment, the tooth may or may not respond to pulp testing methods.
Apical Diagnoses: Assessing Periapical Tissues
Normal Apical Tissues: These tissues are not sensitive to percussion or palpation testing. Radiographically, the lamina dura surrounding the root is intact, and the periodontal ligament space appears uniform. As with pulp testing, comparative testing for percussion and palpation should always begin with normal teeth to establish a baseline for the patient.
Symptomatic Apical Periodontitis: This represents inflammation, usually of the apical periodontium, causing clinical symptoms such as painful responses to biting and/or percussion or palpation. Radiographic changes may or may not be present depending on the stage of the disease. Early stages might show a normal periodontal ligament width, while later stages may exhibit periapical radiolucency. Severe pain upon percussion and/or palpation is highly indicative of a degenerating pulp, and root canal treatment is typically indicated.
Asymptomatic Apical Periodontitis: This refers to inflammation and destruction of the apical periodontium of pulpal origin. It manifests as an apical radiolucency on radiographs but lacks clinical symptoms such as pain on percussion or palpation.
Chronic Apical Abscess: This is an inflammatory reaction to pulpal infection and necrosis characterized by a gradual onset, minimal or no discomfort, and intermittent discharge of pus through a sinus tract. Radiographically, signs of bone destruction, like a radiolucency, are usually present. To pinpoint the source of a draining sinus tract, a gutta-percha cone can be carefully inserted into the sinus tract opening until it meets resistance, followed by a radiograph.
Acute Apical Abscess: This represents an inflammatory reaction to pulpal infection and necrosis characterized by rapid onset, spontaneous pain, extreme tenderness to pressure, pus formation, and swelling of surrounding tissues. Radiographic signs of bone destruction may be absent initially. Patients often experience systemic symptoms like malaise, fever, and lymphadenopathy.
Condensing Osteitis: This is a diffuse, radiopaque lesion representing a localized bony reaction to a low-grade inflammatory stimulus, commonly observed at the apex of a tooth.
Endodontic Diagnosis Table: A Quick Reference
To facilitate a more streamlined diagnostic process, the following endodontic diagnosis table summarizes the key characteristics of each condition, allowing for a quick comparison and reference during clinical assessment.
| Diagnosis | Pulpal Status | Periapical Status | Key Characteristics | Common Symptoms | Radiographic Findings |
|---|---|---|---|---|---|
| Normal Pulp | Normal response | Normal tissues | Symptom-free, mild/transient response to cold. | None | Normal |
| Reversible Pulpitis | Mild inflammation | Normal tissues | Sharp pain to stimuli, subsides quickly. | Pain to cold/sweet, short duration. | Normal |
| Symptomatic Irreversible Pulpitis | Inflamed, cannot heal | Normal tissues or SAP | Lingering pain to stimuli, spontaneous/referred pain, postural pain, ineffective analgesics. | Lingering pain, spontaneous pain, severe response to cold/heat. | Normal or widened PDL space |
| Asymptomatic Irreversible Pulpitis | Inflamed, cannot heal | Normal tissues or AAP | No clinical symptoms, often normal response to testing, history of deep caries/trauma. | None | Normal or widened PDL space |
| Pulp Necrosis | Non-vital | Normal tissues or AAP | No response to pulp testing, asymptomatic (initially). | None initially, may develop SAP or AAP symptoms later. | Normal or periapical radiolucency if AAP develops. |
| Previously Treated | N/A | N/A | Canals obturated, no response to pulp testing. | May be asymptomatic or symptomatic depending on periapical status. | Evidence of root canal filling material. |
| Previously Initiated Therapy | Partial treatment | N/A | Partial endodontic treatment, variable pulp test response. | Variable, depends on pulpal/periapical status. | Evidence of partial endodontic treatment. |
| Normal Apical Tissues | N/A | Normal | Not sensitive to percussion/palpation. | None | Intact lamina dura, uniform PDL space. |
| Symptomatic Apical Periodontitis (SAP) | Variable (often necrotic) | Inflamed | Pain to biting/percussion/palpation. | Pain to biting, percussion, palpation. | Normal PDL width or periapical radiolucency. |
| Asymptomatic Apical Periodontitis (AAP) | Necrotic | Inflamed | No pain to percussion/palpation. | None | Periapical radiolucency. |
| Chronic Apical Abscess | Necrotic | Inflamed | Gradual onset, minimal discomfort, sinus tract. | Minimal discomfort, sinus tract drainage. | Periapical radiolucency, sinus tract may be visible. |
| Acute Apical Abscess | Necrotic | Inflamed | Rapid onset, spontaneous pain, tenderness, swelling, pus. | Spontaneous pain, severe tenderness, swelling, systemic symptoms. | May be normal initially, periapical radiolucency may develop later. |
| Condensing Osteitis | Variable (often necrotic) | Localized bony reaction | Radiopaque lesion at apex, reaction to low-grade inflammation. | Often asymptomatic, may have mild SAP symptoms. | Radiopaque lesion at apex. |
PDL = Periodontal Ligament
SAP = Symptomatic Apical Periodontitis
AAP = Asymptomatic Apical Periodontitis
Diagnostic Case Examples: Applying the Terminology
The following case examples illustrate the application of these diagnostic terms in clinical scenarios.
Figure 1. This mandibular right first molar presented with a history of hypersensitivity to cold and sweets, which had recently subsided. Currently, there is no response to thermal testing, but the tooth is tender to biting and percussion. Radiographic examination reveals diffuse radiopacities around the root apices. Diagnosis: Pulp necrosis; symptomatic apical periodontitis with condensing osteitis. The recommended treatment is nonsurgical endodontic therapy followed by a build-up and crown. The condensing osteitis is expected to regress over time.
Figure 2. Following the placement of a full gold crown on the maxillary right second molar, the patient reported sensitivity to hot and cold liquids, which has now progressed to spontaneous discomfort. Thermal testing with a refrigerant spray elicited pain that lingered for 12 seconds after stimulus removal. Percussion and palpation tests were normal, and radiographs showed no osseous changes. Diagnosis: Symptomatic irreversible pulpitis; normal apical tissues. Nonsurgical endodontic treatment is indicated, with subsequent repair of the access cavity using a permanent restoration. Note also the severe distal caries on the maxillary second premolar, which upon evaluation, was diagnosed as symptomatic irreversible pulpitis (hypersensitive to cold, lingering pain for eight seconds) and symptomatic apical periodontitis (pain to percussion).
Figure 3. The maxillary left first molar exhibits occlusal-mesial caries, and the patient complains of sensitivity to sweets and cold liquids. There is no discomfort on biting or percussion. The tooth is hyperresponsive to thermal (cold) testing, but the pain is not lingering. Diagnosis: Reversible pulpitis; normal apical tissues. The treatment plan involves excavation of the caries followed by a permanent restoration. If pulp exposure occurs during caries removal, nonsurgical endodontic treatment followed by a permanent restoration, such as a crown, would be necessary.
Figure 4. This mandibular right lateral incisor presented with an apical radiolucency discovered during a routine examination. The patient reported a history of trauma more than 10 years prior, and the tooth was slightly discolored. The tooth did not respond to thermal (cold) testing or electric pulp testing, while adjacent teeth responded normally. There was no tenderness to percussion or palpation in the region. Diagnosis: Pulp necrosis; asymptomatic apical periodontitis. Treatment consists of nonsurgical endodontic therapy, followed by bleaching and a permanent restoration.
Figure 5. The mandibular left first molar displays a large apical radiolucency encompassing both mesial and distal roots, with furcation involvement. Periodontal probing depths were within normal limits. The tooth did not respond to thermal (cold) testing, and percussion and palpation tests elicited normal responses. A draining sinus tract was present on the midfacial attached gingiva, which was traced with a gutta-percha cone. Recurrent caries was noted around the distal margin of the crown. Diagnosis: Pulp necrosis; chronic apical abscess. The treatment plan includes crown removal, nonsurgical endodontic treatment, and placement of a new crown.
Figure 6. The maxillary left first molar had undergone endodontic treatment more than 10 years ago. The patient now complains of pain on biting for the past three months. Apical radiolucencies are visible around all three roots. The tooth was tender to both percussion and a fracture-detecting device. Diagnosis: Previously treated; symptomatic apical periodontitis. Treatment involves nonsurgical endodontic retreatment, followed by permanent restoration of the access cavity.
Figure 7. This maxillary left lateral incisor exhibits an apical radiolucency. There is no history of pain, and the tooth is asymptomatic. It shows no response to thermal (cold) testing or electric pulp testing, whereas adjacent teeth respond normally. There is no tenderness to percussion or palpation. Diagnosis: Pulp necrosis; asymptomatic apical periodontitis. Treatment is nonsurgical endodontic therapy and placement of a permanent restoration.
Conclusion: Towards Accurate and Effective Endodontic Care
Recognizing that accurate pulpal and periapical diagnosis is fundamental to determining appropriate clinical treatment, dental professionals can effectively utilize this universal classification system to ensure sound clinical management. The diagnostic terms endorsed by the AAE and American Board of Endodontics, as summarized in our endodontic diagnosis table, provide a practical framework for eliminating potential confusion and enhancing communication.
However, it is crucial to remember that diseases of the pulp and periapical tissues are dynamic and progressive. Clinical signs and symptoms can vary based on the stage of the disease and the patient’s overall health status. Accurate diagnosis relies on a comprehensive approach, integrating patient history, clinical examination, pulp testing, and radiographic findings. No single piece of information should be used in isolation to make a diagnosis. Treatment should never be initiated without a definitive diagnosis. When uncertainty arises, general practitioners should not hesitate to refer patients to an endodontic specialist for further evaluation and expert management.
References
- Glickman GN. AAE consensus conference on diagnostic terminology: background and perspectives. J Endod. 2009;35:1619.
- Seltzer S, Bender IB, Ziontz M. The dynamics of pulp inflammation: correlations between diagnostic data and actual histologic findings in the pulp. Oral Surg Oral Med Oral Pathol. 1963;16:846–871;969–977.
- Berman LH, Hartwell GR. Diagnosis. In: Cohen S, Hargreaves KM, eds. Pathways of the Pulp, 11th ed. St. Louis, MO: Mosby/Elsevier; 2011:2–39.
- Schweitzer JL. The endodontic diagnostic puzzle. Gen Dent. 2009;57(6):560–567.
- AAE Consensus Conference Recommended Diagnostic Terminology. J Endod. 2009;35:1634.
- American Association of Endodontists. Glossary of Endodontic Terms. 8th ed. 2012.
- Glickman GN, Bakland LK, Fouad AF, Hargreaves KM, Schwartz SA. Diagnostic terminology: report of an online survey. J Endod. 2009;35:1625.
- Jafarzadeh H, Abbott PV. Review of pulp sensibility tests. Part I: general information and thermal tests. Int Endod J. 2010;43:738–762.
- Jafarzadeh H, Abbott PV. Review of pulp sensibility tests. Part II: electric pulp tests and test cavities. Int Endod J. 2010;43:945–958.
- Newton CW, Hoen MM, Goodis HE, Johnson BR, McClanahan SB. Identify and determine the metrics, hierarchy, and predictive value of all the parameters and/or methods used during endodontic diagnosis. J Endod. 2009;35:1635.
- Levin LG, Law AS, Holland GR, Abbot PV, Roda RS. Identify and define all diagnostic terms for pulpal health and disease states. J Endod. 2009;35:1645.
- Gutmann JL, Baumgartner JC, Gluskin AH, Hartwell GR, Walton RE. Identify and define all diagnostic terms for periapical/periradicular health and disease states. J Endod. 2009;35:1658.
- Rosenberg PA, Schindler WG, Krell KV, Hicks ML, Davis SB. Identify the endodontic treatment modalities. J Endod. 2009;35:1675.
- Green TL, Walton RE, Clark JM, Maixner D. Histologic examination of condensing osteitis in cadaver specimens. J Endod. 2013;39:977–979.
- Abbott PV, Yu C. A clinical classification of the status of the pulp and the root canal system. Aust Dent J. 2007;52(Endod Suppl):S17–S31.
