Irreversible pulpitis or reversible? Deciding on a heavily restored molar
A 41-year-old woman attends with a 4-day history of intermittent pain in the lower right quadrant. The 46 has a large amalgam with a fractured mesial marginal ridge and a 3 mm periodontal pocket on the mesial aspect; the 47 is heavily restored but sound. Cold testing with ethyl chloride on 46 produces a sharp pain that lingers for about 15 seconds after the stimulus is removed; the 47 responds sharply and settles immediately. Percussion of 46 is mildly tender, probing depths elsewhere are 2–3 mm, and there is no swelling. A radiograph shows the restoration of 46 approaching the pulp with a widened periodontal ligament space but no periapical radiolucency. She is a smoker, takes no medication, and is keen to keep the tooth if possible.
1. How do the special tests and history inform your diagnosis, and what are the reasonable treatment options?
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The key finding is the lingering response to cold on 46, which indicates a pulp that is still responsive but has become symptomatic and irreversibly inflamed. The adjacent 47 gives a normal, non-lingering response and acts as a control, confirming the 46 response is genuine. Mild percussion tenderness and a widened periodontal ligament space suggest early apical involvement but without a radiolucency, so there is no established periapical lesion. The 3 mm mesial pocket may be a false pocket related to the restoration contour or a true periodontal defect; it should be probed carefully and compared with the contralateral side.
Diagnosis: symptomatic irreversible pulpitis with symptomatic apical periodontitis on 46.
Options: root canal treatment or extraction. Restoration alone will not resolve irreversible inflammation. Root canal treatment is reasonable if the tooth is restorable, the periodontal defect is not an endodontic-periodontal lesion with a poor prognosis, and the patient is motivated. Discuss the reduced but real success rate in a tooth with a deep restoration and a possible crack; transillumination and bite testing should be used to exclude a fractured cusp. Extraction with replacement planning is the alternative. Smoking should be raised as a factor affecting healing and periodontal prognosis.
2. She chooses root canal treatment. Outline how you would assess restorability and plan the procedure, including how you would manage the mesial pocket.
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Restorability assessment: check remaining sound tooth structure after caries and restoration removal, whether a ferrule of at least 1.5–2 mm of circumferential dentine can be achieved, whether the tooth is likely to need a cuspal-coverage restoration or onlay, and whether the periodontal support is adequate. Exclude a vertical root fracture or an incomplete cusp fracture; if either is present, extraction is the better option. Discuss the long-term prognosis and cost, and record the consent conversation.
Endodontic planning: achieve profound anaesthesia, which may require a supplemental intraligamentary or buccal infiltration in the presence of irreversible pulpitis; isolate with rubber dam; establish a glide path and determine working length with an apex locator confirmed radiographically; use copious irrigation, ideally with sodium hypochlorite and an adjunct such as EDTA, with attention to extrusion risk; place a temporary coronal seal and plan the definitive restoration promptly.
The mesial pocket should be reassessed after the restoration is refined and the endodontic treatment completed. If it persists and there is no endodontic origin, non-surgical periodontal therapy with oral hygiene instruction and smoking cessation advice is appropriate. If it is a narrow deep defect, referral for periodontal assessment may be needed. Review at 6 and 12 months with radiographs and clinical testing, and warn her that a tooth with this restoration burden may eventually require extraction.