Case ReportChairside and Labside CAD/CAM Workflow for Esthetic and Functional Smile Design RehabilitationDragoș Andrei Adam 1, Andrei B. Faur1,2, and Anca Jivănescu 1,21 Department of Prosthodontics, University of Medicine and Pharmacy “Victor Babes”, B-dul Revolutiei 1989, No. 9, 300580 Timisoara, Romania; [email protected] (D.A.); [email protected] (A.B.F.); [email protected] (A.J.)2 TADERP Research Center, Department of Prosthodontics, University of Medicine and Pharmacy “Victor Babes”, B-dul Revolutiei 1989, No. 9, 300580 Timisoara, Romania* Correspondence: [email protected]; Tel.: +40-744765857Abstract: Esthetic restorations that mimic the patient’s individual naturalness must be shaped and guided by the patient’s complex facial features and physiognomy. CAD/CAM protocols allow us to communicate treatment options with the patient, enabling us to understand the patient’s aesthetic preferences and to convey to the dental technician a viable, functional, physiognomic, and yet patient-accepted treatment option.This case report presents a case of aesthetic frontal rehabilitation based on a fully digital workflow on a young female patient with Kennedy class IV frontal edentulousness. The workflow consisted in a digital smile design protocol, 3D-printed diagnostic wax-up, multiple 3D-printed provisional restorations and a CAD/CAM zirconia fixed dental prostheses.Complex cases of frontal rehabilitation can be functional and aesthetically solved using digital methods and predictable CAD/CAM protocols, by establishing a good communication of the whole team, accurately and thoroughly transmitting all the details related to the aesthetics and natural anatomy of the patient and performing several stages of provisional treatment before the final restoration.Keywords: CAD/CAM, zirconia fixed dental prostheses, 3D-printed provisional restorations, 3D-printed diagnostic wax-up, frontal rehabilitation, digital workflow.1. IntroductionA person s smile is influenced by the size, shape, and color of the teeth, the position, texture, color and lines of the lips and gingiva, as well as the shape of the jaws. The most appealing, fulfilling, and fascinating component of dentistry is creating aesthetically pleasing smile design [1,2]Fulfill the patient’s expectation is a key goal of the aesthetic treatments, and the result be improving the appearance of his or her face and smile. By achieving a simulation and previsualization of the outcome of the suggested therapy, Digital Smile Design (DSD) is a digital tool that aids in the creation and projection of the new smile. A digital mockup of the patient’s new smile is created and presented to them before the actual treatment process begins. This allows for careful examination of the patient’s facial and dental characteristics that play a crucial role in determining the treatment plan [3–5].The development of simplified and predictable protocols in the field of restorative dentistry has been made possible by the advancement of digital technology in dentistry. CAD software can be used to create the temporary and permanent prosthesis as well as the master die model, which can then be produced using 3D printing or milling.Additive procedures have recently been used in restorative dentistry in order to give the dental professional more restorative alternatives. As printing methods are becoming more accurate, the doctor can use digital design (CAD) to create initial diagnostic models, full removable dentures, surgical guides, and temporary restorations. Due to its reproducibility, low cost, and speed of treatment, utilizing a three-dimensional (3D) printed coping to assess the marginal adaptation of the final prosthetic restoration is a solid option. Fixed dental prosthesis using printed materials and techniques may become quite popular in the near future [6,7].Zirconia was initially employed in dentistry at the beginning of the 1990s and has since become widely accessible through the use of CAD/CAM technology. According to recent surveys, dentists frequently propose ceramics, particularly lithium disilicate and zirconia, for both front and back single crowns [8].In the present dental industry, there are several different zirconia materials, and the level of yttrium oxide significantly affects the mechanical and optical capabilities of the restoration. High biological stability and biocompatibility, as well as excellent mechanical qualities, are all characteristics of zirconia. The main drawback of this material is its opacity, which makes it less aesthetically pleasing than other ceramic materials, but can be overcome by stabilizing it with yttrium. While zirconia with 3 mol% yttrium oxide (3 Y-TZP) exhibit high flexural strength, it is not the same for case zirconia with 5 mol% yttrium oxide (5 Y-TZP). Although it is not advised to fabricate fixed dental prostheses larger than three units from 5 Y-TZP, greater translucency may also result in superior aesthetics [9–12].This case report presents a smile design rehabilitation for a young female patient with Kennedy class IV frontal edentulousness, based on a fully digital workflow. The workflow consisted in a digital smile design protocol, 3D-printed diagnostic wax-up, multiple 3D-printed provisional restorations and a CAD/CAM zirconia fixed dental prostheses, in order to restore the smile design considering the facial characteristics, in an accurate and predictable way.2. Case PresentationThe patient was a 26-year-old Asian woman who came to the Department of Prosthodontics Clinic at the University of Medicine and Pharmacy “Victor Babes”, Timisoara, Romania, in February 2023, with a chief complaint regarding her old prosthetic. The patient presented a Kennedy class IV frontal edentulousness, restored with an eleven years old removable partial denture (Figure 1).