Endodontics
What the exam tests
Endodontics tests diagnosis, access, cleaning and shaping, irrigation safety, obturation, restoration, and outcome assessment. The exam favours cases where the pulp diagnosis and apical diagnosis differ.
Core rules
- Diagnose pulpally as normal, reversible pulpitis, irreversible pulpitis, or necrotic; diagnose apically as symptomatic or asymptomatic apical periodontitis, acute or chronic apical abscess, or condensing osteitis.
- Cold testing is the primary pulp sensibility test; electric pulp testing helps but is not decisive in immature or multi-rooted teeth.
- Confirm working length with an apex locator in a dry canal and a radiograph; do not rely on tactile sensation.
- Establish a glide path, shape conservatively, and irrigate with NaOCl. Use EDTA for smear-layer removal; activate irrigants and avoid extrusion.
- Obturate when the canal is clean, shaped, and reasonably dry; finish with a coronal seal.
- Necrotic immature teeth need apexification or regenerative endodontics, not conventional full-length instrumentation.
Worked example
A 35-year-old has lingering pain after cold, tenderness to percussion, and a 3 mm periapical radiolucency on 36. Diagnosis: irreversible pulpitis with symptomatic apical periodontitis. Plan: anaesthesia, isolation, access, locate all canals including the second mesiobuccal canal in maxillary molars and additional canals in mandibular molars, establish working length, prepare chemomechanically, irrigate, and obturate if dry. If exudate persists, place calcium hydroxide and re-evaluate; restore the tooth to prevent coronal leakage.
Traps
- Treating a painful tooth without testing adjacent teeth.
- Using cold response alone to decide on extraction.
- Extruding NaOCl or overinstrumenting the apical foramen.
- Leaving a well-obturated canal without a coronal restoration.