Restorative Dentistry: Operative, Endodontic and Prosthodontic Decisions
Restorative Dentistry in the MDCN assessment tests operative dentistry, endodontics, fixed and removable prosthodontics, and material selection. Questions focus on biological principles, tooth preservation, and whether a restoration or prosthesis is the right plan.
Operative principles
Remove caries and unsupported enamel while preserving sound tooth structure. Design for resistance and retention, and protect the pulp with a suitable liner or base in deep defects. Control moisture for bonding; choose etch-rinse or self-etch systems according to substrate and protocol. Avoid eugenol-containing materials directly on exposed pulp.
Endodontics
Establish working length, maintain a glide path, irrigate with sodium hypochlorite and EDTA, and obturate three-dimensionally. Decide single-visit versus multi-visit treatment by pulpal and periapical status and the ability to control contamination.
Crowns and bridges
A ferrule of about 1.5–2 mm of sound axial dentine improves resistance. Use a chamfer or shoulder margin appropriate to the material, reduce the occlusal surface enough for the chosen ceramic or metal, and verify occlusion in centric and excursive movements.
Worked example
A 26-year-old fractures the crown of 11, with no pulp exposure and 2 mm of coronal tooth remaining. The reasoning is to build up with composite or resin-modified glass ionomer, confirm ferrule, then prepare a crown. Check vitality, occlusion, and aesthetics before cementation.
Traps that cost marks
- Leaving unsupported enamel, which fractures under load.
- Over-reducing a vital tooth or failing to protect a deep preparation.
- Cementing a crown without checking excursive contacts.