Operative Dentistry and Endodontics
What the exam expects
This domain integrates cavity design, restorative technique, pulp biology, and root canal treatment. You must know the principles of tooth preparation, the classification of caries, the indications for pulp capping versus pulpectomy, and the steps and criteria for successful endodontic treatment.
Concepts to master
- Cavity preparation: outline form, resistance form, retention form, convenience form, and removal of infected dentin. Resistance form prevents fracture of the restoration and tooth; retention form prevents dislodgement.
- Caries classification: pit and fissure, smooth surface, root caries, and recurrent caries. Approximal caries is often diagnosed radiographically.
- Pulp therapy: indirect pulp capping when the pulp is not exposed; direct pulp capping when exposed but healthy; pulpotomy removes coronal pulp; pulpectomy removes all pulp tissue.
- Endodontics: access, working length, cleaning and shaping, irrigation (sodium hypochlorite), obturation, and coronal seal. Success depends on the quality of the coronal restoration as much as the root filling.
Traps
A frequent trap is confusing resistance form with retention form. Another is assuming that a radiolucency always means caries; it may be burnout or cervical resorption. In endodontics, questions may test whether a tooth with a periapical lesion is restorable or should be extracted.
Worked rule of thumb
When deciding between pulp capping and root canal treatment, ask: is the pulp exposed, is it reversibly inflamed, and is there a periapical lesion? Reversible inflammation without exposure favors capping; irreversible inflammation or periapical pathology favors root canal treatment.
Study strategy
Practice tracing cavity preparations and endodontic access outlines. Review radiographs for caries and periapical lesions and state the decision rule you would apply.