Pulpal and Periradicular Conditions for Dentists and Endodontists

Pulpal and Periradicular/Periapical Conditions

Pulpal Conditions:

Normal Pulp - A normal pulp is symptom free and will normally be responsive to the electric pulp tester (EPT). When evaluated by thermal testing, the normal pulp produces a positive response that is mild and subsides immediately when the stimulus is removed.
Reversible Pulpitis - Caries, cracks, restorative procedures or trauma may cause a pulp to become inflamed. The patient’s chief complaint is usually of an exaggerated response to thermal stimulus but once the stimulus is removed, the discomfort does not linger. EPT results are responsive.
Irreversible Pulpitis - If the inflammatory process progresses, irreversible pulpitis can develop. Patients may have a history of spontaneous pain and complain of an exaggerated response to hot or cold that lingers after the stimulus is removed. EPT results are usually responsive. The involved tooth will often present with a history of an extensive restoration and/or caries.
- In certain cases of irreversible pulpitis, the patient may arrive at the dental clinic sipping a glass of ice water or applying ice to the affected area. In these cases, cold actually alleviates the patient’s pain as the dental pulp has developed allodynia and is hyperalgesic. Normal body temperature is now causing the nociceptors in the pulp to discharge.10 Removal of the cold causes return of symptoms and can be used as a diagnostic test.
- Irreversible pulpitis can also present as an asymptomatic condition. Internal resorption and hyperplastic pulpitis (pulp polyp) are examples of asymptomatic irreversible pulpitis.
Pulpal Necrosis - Necrosis is a histologic term that denotes death of the pulp. Teeth with total pulpal necrosis are usually asymptomatic unless inflammation has progressed to the periradicular tissues. The pulp will not respond to the EPT and if using a digital EPT, this result should be reported as no response (NR) over 80. The pulp will not respond to thermal tests. The dental record entry for this pulpal diagnosis should be pulpal necrosis.
Pulpless Tooth - A tooth from which the pulp has been removed. For example, a tooth with previous pulpotomy/pulpectomy/root canal debridement or previous root canal therapy should be recorded as a pulpless tooth for the pulpal diagnosis.
Previously Treated - A clinical diagnostic category indicating that the tooth has been endodontically treated and the canals are obturated with various filling materials, other that intracanal medicaments.
Previously Initiated Therapy - A clinical diagnostic category indicating that the tooth has been previously treated by partial endodontic therapy (e.g. pulpotomy, pulpectomy).

Periradicular/Periapical Conditions:

Normal Periradicular Tissues - Normal periradicular tissues will be non-sensitive to percussion and palpation testing. Radiographically, periradicular tissues are normal with an intact lamina dura and a uniform periodontal ligament (PDL) space.
Acute Periradicular Periodontitis - Acute periradicular periodontitis occurs when pulpal disease extends into the surrounding periradicular tissues and causes inflammation. However, acute periradicular periodontitis may also occur as the result of occlusal traumatism. The patient will generally complain of discomfort to biting or chewing. Sensitivity to percussion is a hallmark diagnostic test result of acute periradicular periodontitis. Palpation testing may or may not produce a sensitive response. The PDL space may appear normal, widened, or there may be a distinct radiolucency.
Acute Periradicular Abscess - In this situation, bacteria have progressed into the periradicular tissues and the patient’s immune response cannot defend against the invasion. It is characterized by rapid onset, spontaneous pain, pus formation, and often swelling of the associated tissues. Depending upon the location of the apices of the tooth and muscle attachments, a swelling will usually develop in the buccal vestibule, on the lingual/palatal, or as a fascial space infection. Percussion testing produces a response that is usually exquisitely sensitive. This exaggerated response can help differentiate between acute periradicular periodontitis and the early stages of acute periradicular abscess. Palpation testing produces a sensitive response. Radiographically, the PDL space may be normal, slightly widened, or demonstrate a distinct radiolucency. This periradicular pathosis can occur with a necrotic pulp or a pulpless tooth that has been partially or definitely endodontically treated if continued bacterial contamination and/or leakage occurs.
Chronic Periradicular Periodontitis - When bacteria or bacterial products from a necrotic pulp or pulpless tooth slowly ingress into the periradicular tissues, the patient’s immune system may become involved in a chronic conflict. The resultant inflammatory process causes periradicular bone resorption that manifests as a periradicular radiolucency on the radiograph. Clinically, the patient is asymptomatic. Percussion and palpation testing produce non-sensitive responses.
Subacute Periradicular Periodontitis - The patient will present with mild to moderate symptoms that may include spontaneous pain or discomfort on biting or chewing. The tooth may present with any pulpal diagnosis. Percussion testing produces a mild sensitive response and palpation testing may or may not be sensitive. Clinical symptoms are not as severe as acute periradicular periodontitis. Radiographically, the tooth will present anywhere from a normal periradicular appearance to a distinct radiolucency. These patients must receive endodontic treatment in a timely manner because the condition can quickly progress into acute periradicular periodontitis or an acute periradicular abscess.
Chronic Periradicular Abscess - An inflammatory reaction to pulpal infection and necrosis characterized by gradual onset, little or no discomfort and intermittent discharge of pus through an associated sinus tract. Clinically, the patient is usually asymptomatic because the sinus tract allows drainage of any exudate from the periradicular tissues. EPT and thermal testing are non-responsive. Percussion and palpation testing usually produce non-sensitive responses. Radiographically, a periradicular lesion is associated with the involved tooth. This entity can also occur with a pulpless tooth that has been partially or definitely endodontically treated if continued bacterial contamination and/or leakage occurs.
Focal Sclerosing Osteomeylitis (condensing osteitis) - This entity may be considered a true lesion of endodontic origin (LEO). The involved tooth will have an etiologic factor for low-grade, chronic inflammation such as a necrotic pulp, extensive restorative history or a crack. The patient may be asymptomatic or demonstrate a wide range of pulpal symptoms. EPT and thermal tests may or may not be responsive. Percussion and palpation testing may or may not be sensitive. Radiographically, the involved tooth will present with increased radiodensity and opacity around one or more of the roots. Evidence supporting consideration as a LEO is that 85% of these periradicular radiodensities resolve after endodontic therapy if they have a pulpal diagnosis of irreversible pulpitis.
Focal Osteopetrosis - This entity is not a LEO. The patient will be asymptomatic. EPT and thermal testing are responsive and normal. Percussion and palpation testing will typically be non-sensitive. The involved tooth is usually a virgin tooth or has a normal pulp. Radiographically, the tooth will present with increased radiodensity and opacity around one or more of the roots. No treatment is necessary and the tooth should simply be monitored at periodic recall.

Source: "Clinical Update", Gary Goodell, US Navy, December 2005 (Vol 27, No 9)