Prosthodontics (fixed and removable)
Fixed and removable prosthodontics tests treatment planning, design principles, occlusal concepts, impression and jaw-relation records, and maintenance.
Core concepts
- Fixed partial denture success depends on abutment support, margin fit and biomechanics. Ante's law is a classic guide: the root surface area of the abutments should equal or exceed that of the pontic.
- Ferrule: a 1.5–2 mm circumferential collar of sound tooth structure improves fracture resistance.
- Finish lines: chamfer for metal and metal-ceramic; shoulder or deep chamfer for many all-ceramic systems.
- Removable partial denture components: rests, clasp assembly (rest, proximal plate, reciprocal arm, retentive arm), major connector, minor connector and denture base.
- Kennedy classification: I bilateral posterior edentulous; II unilateral posterior; III unilateral bounded posterior; IV anterior crossing the midline. Applegate's rules apply after planned extractions.
- Complete dentures: maximum extension within functional limits, border seal, neutral zone and balanced occlusion.
Worked example
A patient has a unilateral posterior edentulous space bounded by teeth anteriorly and posteriorly. This is Kennedy Class III. If the space lacks a posterior abutment it becomes Class II. The distinction changes design because a distal extension needs a stress-relieving base and carefully placed rests.
Traps
Do not classify a Kennedy case before planned extractions. Do not ignore the opposing arch and occlusal scheme. Do not use a retentive clasp without a reciprocal element. Do not plan implant prosthodontics without bone and space assessment.