Prosthodontics
This domain covers complete dentures, removable partial dentures, fixed prosthodontics and implant-supported prostheses. The exam tests design principles, occlusal records and the difference between a mechanically sound plan and an arbitrary one.
Complete dentures
- Use primary and custom impressions, record bases and wax rims to record vertical dimension and centric relation. Try-in verifies tooth position, lip support and occlusion.
- Balanced occlusion is desirable in complete dentures. Delivery requires pressure-area adjustment and review of speech, retention and comfort.
Removable partial dentures
- Kennedy Class I is bilateral distal extension, Class II unilateral distal extension, Class III bounded posterior space and Class IV anterior space.
- Rests direct occlusal forces along the long axis. Guide planes aid path of insertion. Major connectors should be rigid and not impinge on gingiva. Distal extension bases need stress relief.
Fixed prosthodontics
- Abutment selection considers crown-root ratio, periodontal support, pulpal status and alignment. Retention and resistance form depend on taper, surface area and path of insertion.
- Pontic design should be cleansable and non-irritating. Occlusal contacts should be checked in centric and excursion.
Worked example
A patient missing lower left molars has a Kennedy Class II modification 1 situation. Reasoning: the edentulous area is unilateral and distal extension, with one additional bounded space. The design needs rest seats, guide planes, a rigid major connector and a stress-relieved distal extension base rather than a simple saddle.
Traps that cost marks
Do not copy a design without surveying. Not every edentulous space needs an implant. Do not increase vertical dimension unnecessarily. Avoid overcontoured connectors that trap plaque. Provisional restorations and occlusal records are not optional extras.