Deep caries with a vital pulp exposure in a highly anxious adult molar
Ms R, 44, attends after five years away from dentistry. Tooth 46 has a large occlusal–mesial composite, deep caries at the mesial margin, and after caries removal there is a 2 mm exposure of a vital, bleeding pulp. Bleeding is controlled within four minutes with 1% sodium hypochlorite on a cotton pellet. The tooth is mildly tender to percussion, not mobile, probing depths are 3 mm or less with no bleeding on probing, and there is no periapical radiolucency; the lamina dura is intact. The mesial wall is lost to gingival level, the distal wall has 2 mm of sound supragingival tissue, and buccal and lingual walls are intact. Ms R reports severe dental anxiety, has a 45-minute appointment today, and says: 'Do whatever lasts longest - I can't afford many visits and I can't face much.'
1. Justify your choice between full pulpotomy/vital pulp therapy and root canal treatment for tooth 46, using the features given.
Read the worked answer
Recommended: root canal treatment, with full pulpotomy as a documented, time-limited alternative rather than the default.
Reasoning for RCT:
- Mature tooth with a closed apex - the biological rationale for vital pulp therapy (revascularisation potential, thin dentine walls) is weaker than in an immature tooth.
- Symptomatic irreversible pulpitis in a posterior tooth with a deep, longstanding lesion - inflammation is likely to extend beyond the coronal pulp; a 2 mm exposure with a history of pain carries a high failure rate for partial/full pulpotomy in this age group, and failure presents later as a flare-up the patient cannot cope with.
- Restoration complexity: the tooth needs cuspal coverage regardless; a failed pulpotomy means re-entering a heavily restored tooth.
- Anxiety and visit tolerance: an unpredictable late failure is worse for this patient than a planned course of treatment.
Reasons a pulpotomy could be offered: single-visit completion (fits a 45-minute slot), avoids an extraction in an anxious patient, and evidence supports it in selected cases if haemostasis is achieved and a hydraulic calcium silicate cement is used with a sealed coronal restoration. If chosen, consent must state the uncertainty and the need for review at 6 and 12 months, with RCT as the fallback. It is a judgement call, not a rule.
2. Set out the restorative plan after RCT, including how much tooth structure must be preserved and why.
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Plan: RCT → core build-up → cuspal coverage (onlay or crown) with a ferrule of at least 1.5–2 mm on the remaining walls.
- Do not reduce the distal 2 mm wall further. That wall is the ferrule; circumferential dentine height is the single strongest predictor of resistance to fracture in a root-filled molar.
- Mesial wall lost to gingival level → the mesial cavity margin must be brought supragingival. Options: orthodontic extrusion (unrealistic here), surgical crown lengthening (affects the furcation - caution on a lower molar), or a deep-margin onlay/overlay design using a well-sealed gingival floor with a clearable margin.
- Cuspal coverage is mandatory - a root-filled molar restored with a direct intracoronal filling has a markedly higher fracture and re-treatment rate.
- Material choice should balance the patient's ability to tolerate visits and moisture control: a single-visit adhesive overlay is defensible; a laboratory crown needs a second appointment and a provisional, which may be poorly tolerated by an anxious patient.
- Sequence matters: endodontic access should be restored with a sealed, non-setting or provisional material that does not interfere with the final adhesive bond.
3. Ms R says she will accept the root canal but refuses the cuspal coverage because of cost. How do you manage this?
Read the worked answer
Do not simply agree; renegotiate the plan with explicit risk information, and document it.
- Clarify what she is declining - not 'the crown' but the protection of a root-filled molar. Explain in concrete terms: without cuspal coverage the tooth has a substantially higher chance of splitting, and a split molar often cannot be saved, meaning an extraction and a bridge/implant - likely more expensive than the restoration she is avoiding.
- Offer staged, affordable options: complete the RCT now to remove pain and infection; place a durable sealed core; agree a defined review date; then plan the overlay when finances allow. This is a legitimate harm-reduction sequence if the core is well sealed.
- Consider alternatives honestly: extraction now with a clear explanation of the consequences (space loss, drifting, replacement costs) may be the rational choice for some patients - present it as an option, not a threat.
- Record an informed refusal: what was offered, what was declined, the risks explained, the review interval, and that she was invited to return sooner if symptoms change. Record the discussion in her own words where possible.
- Address the underlying barrier - anxiety and cost. Offer a written estimate, spread of payments, and anxiety management (tell–show–do, short appointments, agreed stop signal), and consider whether referral for sedation is appropriate.
The examiner is looking for evidence that you protect the patient's autonomy and your own professional position through clear documentation.