Diagnostic tooth preparations are typically performed on what before actual clinical preparation?

Diagnostic tooth preparations are conducted on articulated casts to simulate how the final restoration will fit and function within the patient's occlusion. These casts represent a three-dimensional model of the patient’s dental arch and occlusion, which allows for thorough analysis of the overall dental structure and its relationship with adjacent and opposing teeth. By working on articulated casts, clinicians can assess the necessary tooth reduction, esthetic considerations, and potential adjustments needed before executing the actual tooth preparation in the patient's mouth.

Using articulated casts helps in planning the treatment comprehensively, as it allows the dentist to visualize and test the proposed restorations without any risk to the patient's health or comfort. This approach also supports better communication and pre-evaluation of the aesthetics and functional aspects of the outcome, which is critical for successful prosthetic dentistry.