The mock-up technique is a widely used clinical method to achieve successful esthetic and functional treatments. Several methods have been described to fabricate the mock-up, either directly in the mouth or indirectly using a silicone index or CAD/CAM options. The mock-up mainly serves as a guide during the preparation stage, but it is also a useful communication and validation tool. Based on the controlled depth preparation concept, the mock-up ensures a specific restoration thickness sufficient for the ceramic and respectful of the enamel tissue. Any error in fabricating the mock-up may cause debonding complications and have a negative impact on the esthetic result. Currently, most mock-ups are created indirectly using a silicone index injected with a temporary resin that mimics the final esthetic project. The present article reports on the protocol involved in a clinical study conducted to validate the precision of reproducibility of this indirect method. Two different options for creating the silicone index were investigated. Twenty mock-ups were realized on the same subject by the same operator. Each mock-up was 3D scanned to compare its reproducibility using the superimposition of 3D meshes. The results show that the reproducibility of indirect mock-ups is clinically acceptable (~ 100 µm), regardless of the fabrication method used. However, a combination of standard silicone and a rigid tray produces better results than hard silicone alone.