After receiving the RPD framework from the lab, which cast will be used for all subsequent clinical appointments and lab work?

The master cast is the correct choice because it serves as the definitive model used for fabricating the removable partial denture (RPD) framework and subsequent components. This cast is created from a precise impression taken after the initial phase of treatment. It includes all relevant anatomical features and is used to capture the detailed contours necessary for proper fit and function of the RPD.

Using the master cast facilitates accurate adjustments, allows for proper verification of the fit of the framework, and provides a reference for creating additional prosthetic components as treatment progresses. The master cast also aids in maintaining consistent communication between clinician and laboratory, ensuring that any modifications or additions to the prosthesis are made with the highest level of accuracy.

Other types of casts, such as diagnostic casts, are used primarily for treatment planning and visualization but do not provide the same level of detail required for the final prosthetic design. Duplicate casts may be created from the master cast for certain uses, but they are not the primary cast utilized for the clinical processes leading to the construction of the RPD. Impression casts, while important for the initial stages of creating models, do not represent the final, detailed anatomy necessary for RPD fabrication.