Clasps, Wires & Attachments

Choosing Clasps and Retentive Components

• Akers (C) Clasp — The Akers clasp is the most common RPD retainer -- a circumferential clasp that wraps the buccal surface and engages a mesial or distal undercut. It suits posterior abutment teeth with adequate bucco-cervical undercut depth (0.25-0.5 mm) and reasonable aesthetics tolerance.
• RPI Clasp System — The RPI (rest, proximal plate, I-bar) clasp applies mesial rests and I-bar retainers to reduce torque on abutment teeth. RPI is the preferred design for distal-extension RPDs where stress reduction on the terminal abutment is a priority.
• Wrought Wire Clasps — Wrought wire clasps (usually 18-gauge round wire) are adapted chairside and soldered to the metal framework. Their flexibility makes them more retentive on periodontally compromised abutments; they can be adjusted without the risk of fracture common in cast clasps.
• Prefabricated Wax Clasps — Prefabricated plastic wax-up clasps speed up RPD framework design by providing standardised clasp forms for casting. They ensure consistent clasp geometry across units and reduce technician wax-up time; available in multiple arm thicknesses.
• Precision Attachments — Precision attachments (Dalbo, Rhein 83, Preci-Clix) offer better retention and aesthetics than conventional clasps. The patrix is incorporated in the crown; the matrix in the partial denture framework -- they require precise crown preparation and increased lab skill.
• Wire Gauges — Gauge selection determines clasp flexibility -- 19-gauge wire is stiffer, 21-gauge is more flexible and adjustable. Use 19-gauge for round clasps on molar abutments requiring strong retention; 21-gauge for premolar and anterior wires where flexibility is needed.

RPD Retentive Component Types

How to Select RPD Clasps and Wires

1. Survey the diagnostic cast to identify undercut depth and location on abutment teeth.
2. Choose Akers clasp for standard bounded saddles with adequate posterior undercut.
3. Select RPI or I-bar system for distal-extension cases to minimise torque on the terminal abutment.
4. Use wrought wire clasps on periodontally compromised abutments where flexibility and adjustability are needed.
5. Consider precision attachments where the patient demands metal-free visible clasps and adequate crown support exists.

Availability & Delivery in Egypt

MedSTA supplies RPD clasps, wires and precision attachments to dental laboratories across Egypt with EGP pricing and nationwide delivery. All components are compatible with standard cobalt-chromium RPD frameworks.