OBJECTIVE The ability to control the reduction of tooth structure in a precise and measurable way during the preparation of ceramic veneers is a clinical challenge. The objective of this article is to introduce a new digital technology that can be used to address this challenge showing its advantages and limitations. First Fit is a digitally guided tooth preparation system that can be used to control the accurate and efficient preparation of teeth. In some cases, the system can be used to prepare the teeth for previously made restorations based on planned digital reduction. METHODS The First Fit system uses 3D-printed guides and a specially designed handpiece for guided veneer preparation using either a one-step or a two-step approach. In the one-step approach, final restorations are produced prior to preparation of the teeth using reduction guides, and veneers are cemented on the same day as preparation. The two-step approach includes a preparation phase during which the teeth are prepared using a combination of the reduction guides and free hand techniques. Cementation is then completed at a second appointment. CONCLUSIONS The First Fit system controls and guides veneer preparation with a minimally invasive approach. In some cases, it enables the production of veneers before tooth preparation, alleviating the need for provisional restorations. CONCLUSIONS The guided restorative dentistry technique described here utilizes digital CAD-CAM technology to achieve predictable and accurate results in a minimally invasive and efficient manner.