Intraoral and facial scanner, guided surgery and carbon. The future of dentistry?

OBJECTIVES The presentation of a clinical case characterized by a totally digital workflow, effected by means of an intraoral scanner, software design of computer-guided surgery and a facial scanner for the production of prosthetic restoration, finalized with a substructure in carbon and single zirconia crowns 600 MPa. MATERIALS AND METHODS The patient was a 57-year-old woman and came to the attention of the authors, at Dentistry Clinic Giorgio Vogel in Milan, requesting prosthetic restructuring of the superior dental arch. The patient had a removable complete denture supported by 4 attachments (root spherical connections) fixed onto elements periodontally severely compromised, characterized by pain in percussion and 2nd degree mobility. The request of the patient was orientated towards a fixed rehabilitation, and, after a radiographic analysis, the proposed solution was the avulsion of residual elements and rehabilitation through the production of an implant-supported fixed prosthesis. It was decided to utilize a totally digital approach using an intraoral scanner, computer-guided surgery and facial scanner for the rehabilitation design. A scan of the total removable prosthesis is performed with an intraoral scanner, and from the STL file thus obtained the laboratory obtains a radiological template. After evaluating its stability and correct positioning in the patient's oral cavity, a cone-beam computed tomography is performed. Once the TC cone-beam had been executed, the surgery operation design followed, with the virtual positioning of the implants and of the relative surgical template through dedicated software. Six bone level implants in computer-guided surgery through a flapless approach were then positioned. After 10 weeks the positioning of the scan abutment took place together with the identification of the positions of the implants through an intraoral scan. Furthermore, a facial scan was effected to permit the laboratory to obtain all the facial parameters which produced a perfect integration with the face of the patient. A prosthetic test with restoration in PMMA was carried out to analyze the functional and cosmetic results. Once optimized and the patient was satisfied, the definitive restoration took place, which was realized by producing a carbon substructure on which single zirconia crowns were applied with adhesive technique. RESULTS AND CONCLUSIONS The use of this technology permitted the insertion of the implants in a prosthetically guided position, ensuring a functional and aesthetic restoration. Furthermore, thanks to the flapless approach, surgical discomfort for the patient has been reduced to a minimum. Thanks to the facial scan it was possible to share with the laboratory fundamental information relative to the face and to the facial expressions of the patient, thus permitting a rehabilitation capable of integrating in an optimal way with the face and which took account of the physiognomical and functional proportions. Choosing carbon as a material permitted the realization of a resistant and extremely light restoration, and the utilization of zirconia 600 MPa for the production of the single crowns guaranteed resilience, with results comparable to other esthetic materials. CLINICAL SIGNIFICANCE Unlike computer-guided surgery and impressions taken with intraoral scanners which now enjoy extensive dedicated literature, intraoral scanning and the use of carbon as a material for the substructure present a small number of dental applications. The case described has a limited follow-up, but the clinical impressions relating to the precision of the surgical result and the functionality of the restoration obtained are extremely positive and promising for further applications of the described protocol.