Which item is specifically noted for use in prosthetic procedures to hold models together?

The articulator is specifically designed for prosthetic procedures to hold dental models together accurately. This device simulates the natural movement of the jaw and allows dental professionals to mount upper and lower dental models, providing a reliable framework for creating crowns, bridges, dentures, and other dental prosthetics. By mimicking the bite and jaw movement, the articulator helps ensure that the prosthetic fits well and functions properly in the patient's mouth.

The other options, while useful in a dental lab, do not serve the same function as the articulator. For instance, a model holder typically refers to a simple device for stabilizing a single model rather than providing a complete articulation like the articulator does. A prosthetic frame may refer to the structure used to support prostheses but is not focused on joining dental models. A model stand is generally used for holding models upright during work but does not facilitate the articulation of the jaw movement or proper alignment of dental components needed in prosthetic procedures.