Restorative Dentistry and Endodontics
What this domain tests
Restorative and endodontic items test clinical judgement rather than memorised sequences: caries diagnosis and tissue removal, adhesive protocol, preparation design, pulp diagnosis, canal preparation, obturation, and the transition from root canal treatment to a durable coronal seal. The board expects you to justify each step by biological principle.
Core rules
- Caries removal is selective: enamel margins fully cleaned, peripheral dentine caries-free, soft dentine left over the pulp only when the tooth is symptomless and remineralisation is planned.
- Adhesive strategy follows substrate: phosphoric acid on enamel, selective enamel etching with universal adhesives on dentine, and no over-drying of etched dentine.
- Rubber dam is standard for endodontics; it is a safety and quality requirement.
- Working length is the apical constriction, 0.5-1.0 mm short of the radiographic apex, with apex-locator readings confirmed radiographically.
- Shaping follows a glide path and crown-down sequence with copious sodium hypochlorite (1-5.25%), EDTA for smear layer, and a matched cone fit.
- The coronal restoration must provide ferrule; a post does not replace missing tooth structure.
Worked example
A 42-year-old has a root-filled mandibular first molar, a 6-mm buccal pocket, a 2-mm short gutta-percha fill, and a periapical radiolucency. Reasoning: the pocket may be endodontic in origin, so retreatment comes before periodontal surgery; the short fill and open coronal margin explain persistent apical periodontitis; the tooth lacks ferrule because the cusps are unsupported. Plan retreatment, re-evaluation at three months, then cuspal-coverage restoration or extraction.
Traps
Calling a deep pocket around a root-filled tooth periodontitis; instrumenting beyond the apex; extruding irrigant through a perforation; accepting an inadequate ferrule.