Endodontics · patient case with 3 questions

Post-restorative sensitivity in the mandibular right posterior sextant

Patient: Adult periodontal maintenance patient

Chief complaint: Sensitivity after restorations were placed in teeth #28 and #29.

Background: Controlled periodontal patient. The restorations were well executed.

Current findings: Gingival recession of 3 mm and bone loss. Radiographs of the region are provided.

Question 1

The restorations were technically sound. Why does the patient perceive sensitivity in #28?

Show answer and explanation

Correct answer: C. Referred pain from #29

A. Nothing in the history indicates necrosis of #28.
B. Occlusal trauma produces pain on percussion and biting, mediated by the periodontal ligament — which, unlike the pulp, DOES localise well.
C. CORRECT. Pulpal pain is notoriously poorly localised, because the pulp contains no proprioceptors. Pain is readily REFERRED between adjacent teeth within the same quadrant and across the same nerve distribution. The symptomatic tooth is #29; #28 merely receives the referral. This is exactly why pulp testing of multiple teeth, not just the one the patient points at, is essential.
D. A cracked cusp gives sharp pain on release of biting pressure, not this presentation.

Note: Referred pain does not cross the midline, and mandibular posterior teeth commonly refer to the opposing arch on the same side.

The radiograph of #29 shows caries at and below the cementoenamel junction, with localised bone loss. What is the cause of the bone loss?

Show answer and explanation

Correct answer: B. The caries and its associated local inflammation

A. Occlusal trauma alone widens the periodontal ligament space but does not by itself cause attachment loss without inflammation.
B. A carious lesion extending to and below the CEJ acts as a persistent plaque-retentive factor and a direct source of local inflammation, driving localised crestal bone loss in that interproximal site.
C. Endodontic pathology produces a PERIAPICAL radiolucency at the root apex, not crestal bone loss at the CEJ. The described lesion is cervical.
D. A vertical root fracture classically gives a J-shaped or halo radiolucency tracking along the root, which is not described here.

Which pulp testing approach best establishes which tooth is actually responsible?

Test only the tooth the patient identifies as painful
Rely on the radiograph alone
Rely on percussion alone
Test several adjacent and contralateral teeth to establish a baseline before testing the suspect tooth

Show answer and explanation

Correct answer: D. Test several adjacent and contralateral teeth to establish a baseline before testing the suspect tooth

A. Testing only the indicated tooth is precisely the error that referred pain sets you up to make.
B. Radiographs show periapical change only after substantial bone demineralisation, and reveal nothing about pulp vitality.
C. Percussion assesses the periodontal ligament, and so distinguishes periapical involvement, but does not assess pulp vitality.
D. CORRECT. Because pulpal pain refers so readily, you must test MULTIPLE teeth, including a known-healthy contralateral control, to establish that patient's normal response before interpreting the suspect tooth. Testing one tooth in isolation yields an uninterpretable result.