With cast models for an RPD (removable partial denture), what do you need to do to register the interocclusal relationship?

Correct answer: C. Make wax rims

• A. INCORRECT — Silicone bite registration material can be used as an adjunct or alternative in some cases with adequate natural tooth contacts, but for RPD cases with edentulous spans, wax rims on baseplates are the primary method.
• B. INCORRECT — Applying wax only on top of teeth is incomplete; a proper occlusal record requires a structured wax rim on record bases for accurate relationship registration.
• C. CORRECT — Wax occlusal rims (baseplate wax on a record base) are the standard method for recording interocclusal relationships in RPD prosthodontics when natural tooth contacts are insufficient or absent in the edentulous areas. They allow vertical dimension and centric relation to be established.
• D. INCORRECT — Occlusion checker (articulating paper) checks existing occlusion; it does not register interocclusal relationships for prosthesis fabrication.