On
Mock-up ,, why ⁉️

Fabrication of Mock-up provides a preview of the final results before proceeding with the final impression or even preparation of the natural teeth.
Also, we can use it as a temporary restoration that gives the dentist a working model on which any necessary alterations in the treatment plan may be made. Therefore, the temporary restoration acts as the blueprint for a successful aesthetic result.
👉🏻 Since the final impression will be made at a subsequent appointment ;                            
 The patient has time to adjust to and voice any criticism of the temporary restoration. It is also motivating your patient to start your treatment plan.
 The dentist also has the additional opportunity to alter the tooth preparation, the surrounding tissue, and the shape, size, or arrangement of the temporary restoration.
👉🏻 During this appointment make an impression and study cast of the finished temporary restoration - This can be done while waiting for the anesthetic to take effect for the final impression. Send this impression along with the final impression, to the laboratory. This will eliminate any guesswork by the laboratory technician as to the definitive restorations desired.