Prosthodontics
Diagnosis and design
Fixed and removable prosthodontic questions reward systematic thinking: what is missing, what remains, what will support the restoration, and how forces reach the supporting structures.
Removable partial dentures
- Kennedy classification and Applegate's rules: classify by the most posterior edentulous area; missing third molars are not counted when they will not be replaced; a missing second molar is not counted when the first molar is present and the space will not be restored.
- Components: rests provide support, direct retainers provide retention, and major and minor connectors plus reciprocating elements provide stability and rigid connection.
- A circumferential clasp suits the terminal abutment; the RPI or I-bar design is favored for distal extension bases, which also benefit from an altered cast and functional impression.
Complete dentures
Border molding, posterior palatal seal at the vibrating line, jaw relation records, vertical dimension, neutral zone, balanced occlusion, and tooth arrangement. Retention depends on adhesion, cohesion, and atmospheric pressure.
Fixed prosthodontics
Preparation principles: adequate reduction, a well-defined margin (chamfer, shoulder, or knife edge), a single path of insertion, and a ferrule of at least 1.5–2 mm on endodontically treated teeth. Cement choice depends on retention needs, tooth vitality, and esthetics.
Traps
Questions conflate support, stability, and retention. Also, the posterior palatal seal is placed at the vibrating line, not at the fovea palatini, and a Class II modification is described by the number of modification spaces.
Rule of thumb
Classify the arch first, then ask which function fails: support (rests), retention (clasps), or connection (major connector). Fix the weakest link.