In what situation would a dentist typically take a final impression?

Taking a final impression is a critical step in the dental process, particularly when creating restorations such as crowns or dentures. This impression provides a highly accurate mold of the patient's teeth and surrounding tissues, which is essential for ensuring that the final restoration fits properly and functions well within the mouth.

When a dentist prepares to place a crown or denture, they typically need to capture the exact contours of the prepared tooth or the edentulous area, as well as the relationship to neighboring teeth and the occlusion (the bite). The final impression is usually taken after necessary tooth preparations have been completed, ensuring that the lab has the precise details required to fabricate a restoration that achieves both aesthetic and functional goals.

In contrast, taking impressions during other times such as before administering anesthesia, after tooth extractions, or during routine cleanings does not serve the same purpose. Pre-anesthesia impressions are unnecessary since there is no work being done on teeth at that moment. After tooth extractions, impressions may not accurately capture the current dental structure, making them unsuitable for creating restorations. Routine cleanings do not typically involve the need for impressions, as they focus on maintaining oral health rather than planning for prosthetic devices.