Endodontic Diagnosis and Treatment Planning
This domain tests test selection, interpretation, and the judgement to treat, refer, or extract.
Sensibility testing
- Cold spray and electric pulp testing (EPT) both stimulate A-delta fibres; neither measures blood supply, so the term vitality test is a misnomer.
- Use at least two different tests plus percussion, palpation and a periapical radiograph.
- EPT is unreliable in immature teeth with open apices, recently traumatized teeth, calcified or heavily restored canals, and in patients with a cardiac pacemaker (older units).
- A negative response after trauma is re-tested in 2-4 weeks before declaring necrosis.
Interpreting misleading results
False negative: calcified canal, recent trauma, immature apex. False positive: referred sensation, adjacent tooth, conductive contact with a metal restoration or the EPT clip, anxious patient.
Imaging
Two angled periapical radiographs first. Cone-beam CT only when the result changes management, using a limited field of view and small voxel, interpreted by a trained reader (AAE/AAOMR position). It is superior for missed canals, vertical root fracture, resorption and small lesions.
Planning variables
Restorability and ferrule, periodontal probing and support, strategic value, occlusal scheme, medical status (anticoagulants, antiresorptives, irradiated jaws), patient preference. A necrotic asymptomatic tooth with a small lesion is usually treated; a cracked, hypermobile or untreatably perforated tooth is extracted.
Worked example
Mandibular first molar with a large amalgam: dull ache on chewing, no response to cold or EPT, tender to percussion, 4 mm mesial radiolucency. Diagnosis: necrotic pulp with symptomatic apical periodontitis. Plan: verify restorability, treat all mesial and distal canals, and exclude a crack before committing.
Traps
Declaring a tooth dead from a single negative EPT; omitting periodontal probing; treating an unrestorable tooth; ordering CBCT without a clinical question.