Endodontic Emergencies, Pain and Pharmacology
Pain and Pharmacology tests mechanisms of endodontic pain, local anaesthesia, and safe prescribing in emergency and routine care.
Core rules
- Pulpal pain is mediated by A-delta and C fibres; inflammation lowers the activation threshold and makes anaesthesia harder, especially in irreversible pulpitis.
- Inferior alveolar block failure in mandibular molars is common; supplemental buccal infiltration, intraligamentary injection, or intraseptal injection may help.
- NSAIDs are first-line for inflammatory endodontic pain when not contraindicated; paracetamol can be combined; opioids are rarely indicated.
- Antibiotics are not analgesics and are not indicated for pulpitis or a localised abscess after drainage without systemic signs.
- Check allergy, pregnancy, renal disease, anticoagulants, and asthma before prescribing; document drug, dose, and review.
Worked example
A mandibular molar with irreversible pulpitis remains painful after a standard inferior alveolar block. Rather than repeating the same block, the clinician adds a buccal infiltration and an intraligamentary injection, then performs pulpectomy. An NSAID is prescribed. Antibiotics are withheld because there is no systemic involvement.
Traps that cost marks
Repeating an ineffective block without supplementation; using antibiotics for pain; prescribing opioids first; and ignoring medical contraindications or paediatric dosing.