Prosthodontics
What the exam tests
Prosthodontics questions cover treatment planning, occlusion, removable and fixed designs, complete dentures and implant-supported prostheses. The exam looks for a defensible plan that respects tissue health, biomechanics and the patient's ability to maintain the restoration.
Core rules and concepts
- Fixed prosthodontics: assess abutment prognosis, ferrule and path of insertion before preparation. Avoid cantilevers on single implants; verify passive fit and marginal adaptation. Choose monolithic zirconia, lithium disilicate or metal-ceramic according to load, aesthetics and opposing dentition.
- Removable partial dentures: classify with Kennedy, prepare rest seats, and use rigid major connectors and appropriate clasps. The path of insertion must be planned; avoid designs that load teeth with tissue-borne forces.
- Complete dentures: border molding and an accurate posterior palatal seal prevent dislodgement. Set the vertical dimension with 2–4 mm of freeway space and develop balanced occlusion.
- Implant prosthodontics: screw retention is preferred when access allows; develop an emergence profile that supports soft tissue; avoid excessive cantilever length and premature occlusal contact.
- Occlusion: use mutually protected occlusion where appropriate; check centric relation and excursive contacts rather than relying on a single static bite.
Worked example
A mandibular Kennedy class II patient is missing 36 and 37, with 35 tipped mesially. Reasoning: prepare a rest seat on 35, use a rigid lingual plate major connector, and design a clasp that resists the class II lever. Do not simply extend a saddle distally without rests, because that produces torque on 35.
Traps
Overextended denture borders; omitting rest seats; choosing a path of insertion that locks the framework; using a non-passive implant framework; polishing only the occlusal surface of zirconia; ignoring the opposing arch.