Objective: To describe how to perform, in a simple manner, a digital wax-up with open source software for a clinical application involving direct composite resin restorations. Report:The clinical technique described presents a simple and highly predictable way of performing direct restorations with the help of a digital wax-up made with open source software. It uses an open source digital tooth library to reestablish a more harmonious smile architecture, specifically of teeth that were worn due to parafunction, and restored with direct composite resin restorations. Conclusions: Thanks to the technology that was used in this case, fast, affordable and accurate results could be obtained. In addition, digital files can be stored, saving material, time, and space, and allowing identical replication of the work either virtually or printed at any time, if needed.