The use of dental implants and bone grafts to orally rehabilitate patients affected by ED is a valuable service with no difference in the results compared with unaffected patients, at least in adults.

The aim of the study was to evaluate the accuracy of zygomatic implant placement using customized bone-supported laser-sintered titanium templates. Pre-surgical computed tomography (CT) scans allowed to develop the ideal virtual planning for each patient. Direct metal laser-sintering was used to create the surgical guides for the implant placement. Post-operative CT scans were taken 6 months after surgery to assess any differences between the planned and placed zygomatic implants. Qualitative and quantitative three-dimensional analyses were performed with the software Slicer3D, recording linear and angular displacements after the surface registration of the planned and placed models of each implant. A total of 59 zygomatic implants were analyzed. Apical displacement showed a mean movement of 0.57 ± 0.49 mm on the X-axis, 1.1 ± 0.6 mm on the Y-axis, and 1.15 ± 0.69 mm on the Z-axis for the anterior implant, with a linear displacement of 0.51 ± 0.51 mm on the X-axis, 1.48 ± 0.9 mm on the Y-axis, and 1.34 ± 0.9 mm on the Z-axis for the posterior implant. The basal displacement showed a mean movement of 0.33 ± 0.25 mm on the X-axis, 0.66 ± 0.47 mm on the Y-axis, and 0.58 ± 0.4 mm on the Z-axis for the anterior implant, with a linear displacement of 0.39 ± 0.43 mm on the X-axis, 0.42 ± 0.35 mm on the Y-axis, and 0.66 ± 0.4 mm on the Z-axis for the posterior implant. The angular displacements recorded significative differences between the anterior implants (yaw: 0.56 ± 0.46°; pitch: 0.52 ± 0.45°; roll: 0.57 ± 0.44°) and posterior implants (yaw: 1.3 ± 0.8°; pitch: 1.3 ± 0.78°; roll: 1.28 ± 1.1°) (p < 0.05). Fully guided surgery showed good accuracy for zygomatic implant placement and it should be considered in the decision-making process.

Objectives The present study aimed to analyze the behaviors of three intraoral scanners (IOSs): evaluating the interdistance and axial inclination discrepancies in full-arch scans, predictable errors were searched. Materials and methods Six edentulous sample models with variable numbers of dental implants were used; reference data were obtained with a coordinate-measuring machine (CMM). Each IOS (i.e., Primescan, CS3600, and Trios3) performed 10 scans per model (180 total scans). The origin of each scan body was used as a reference point to measure interdistance lengths and axial inclinations. Precision and trueness of interdistance measurements and axial inclinations were evaluated to address error predictability. Bland–Altman analysis, followed by linear regression analysis and Friedman’s test (plus Dunn’s post hoc correction), was performed to evaluate the precision and trueness. Results Regarding interdistance, Primescan showed the best precision (mean ± SD: 0.047 ± 0.020 mm), while Trios3 underestimated the reference value more than the others (p < 0.001) and had the worst performance (mean ± SD: −0.079 ± 0.048 mm). Concerning the inclination angle, Primescan and Trios3 tended to overestimate angle values, while CS3600 underestimated them. Primescan had fewer inclination angle outliers, but it tended to add 0.4–0.6° to the measurements. Conclusions IOSs showed predictable errors: they tended to overestimate or underestimate linear measurements and axial inclinations of scan bodies, one added 0.4–0.6° to the angle inclination values. In particular, they showed heteroscedasticity, a behavior probably related to the software or the device itself. Clinical significance IOSs showed predictable errors that could affect clinical success. When performing a scan or choosing a scanner, clinicians should clearly know their behaviors.

The success of implant-supported fixed complete dental prostheses (ISFCDPs) depends on multiple factors: some are related to the fixtures, such as fixture material, surface characteristics, positioning, and type of connection to prosthetic components; others are related to the prostheses, such as design and materials used. Zirconia is a material widely used in fixed prosthodontics, whether on natural teeth or on implants, with excellent results over time. Regarding the use of zirconia for ISFCDPs, the 2018 ITI Consensus Report stated that “implant-supported monolithic zirconia prostheses may be a future option with more supporting evidence”. Since CAD/CAM technology and zirconia are being continuously innovated to achieve better results and performances over time, a narrative review of the literature seems necessary to focus research efforts towards effective and durable solutions for implant-supported, full-arch rehabilitations. The objective of the present narrative review was to search the literature for studies regarding the clinical performance of zirconia-based ISFCDPs. According to the results of this review, the use of zirconia for ISFCDPs showed good clinical outcomes, with high survival rates ranging from 88% to 100% and prosthetic complications that were restorable by the clinicians in most cases.

Objectives The present study aimed to analyze the behaviors of three intraoral scanners (IOSs): evaluating the interdistance and axial inclination discrepancies in full-arch scans, predictable errors were searched. Materials and Methods Six edentulous sample models with variable numbers of dental implants were used; reference data were obtained with a coordinate-measuring machine (CMM). Each IOS performed 10 scans per model (180 total scans). The origin of each scan body was used as a reference point to measure interdistance lengths and axial inclinations. Precision and trueness of interdistance measurements and axial inclinations were evaluated to address error predictability. Bland–Altman analysis, followed by linear regression analysis and Friedman’s test (plus Dunn’s post hoc correction), was performed to evaluate the precision and trueness. Results Regarding interdistance, Primescan showed the best precision (mean±SD: 0.047±0.020mm), while Trios3 underestimated the reference value more than the others (p < 0.001) and had the worst performance (mean±SD: −0.079±0.048mm). Concerning the inclination angle, Primescan and Trios3 tended to overestimate angle values, while CS3600 underestimated them. Primescan had fewer inclination angle outliers, but it sporadically added 0.2–0.4° to the measurements. Conclusions IOSs showed predictable errors: they tended to overestimate or underestimate linear measurements and axial inclinations of scan bodies, one added occasionally 0.2-0.4° to the angle inclination values. In particular, they showed heteroscedasticity, a behavior probably related to the software or the device itself. Clinical Significance The presence of constant errors and unique heteroscedastic behavior were demonstrated for the first time.

An important issue with digital impression techniques is the difficulty in replicating the subgingival zone, particularly when abutments are prepared with a vertical finish line. We propose a novel procedure, the reverse subgingival scan (RSS), to depict the subgingival area via digital impression without a retraction cord or the distortion of the sulcus. The software workflow, beginning with a digital dental impression, was performed using Exocad® (Align Technology) and Meshmixer® (Autodesk). The approach is based on the direct alignment of the surface of abutments, which is used as a reference point. The efficacy of the RSS approach was confirmed via fit tests, radiographic control assessments, and evaluations of the rate of tissue compression of the final prosthetic restoration, so long as the provisional had a perfect fit. RSS yields information on the transversal dimension and depth of the gingival sulcus. The procedure depends on the quality and characteristics of the provisional restoration, and is suitable only for cases in which the finish line of the final crown is at the same level or more coronal than that of the provisional.

Introduction: A case report is presented to demonstrate advantages of a new fully digital approach, from planning through to execution to immediate loading implant-prosthetic rehabilitation. Until now, the function of the diagnostic wax-up has not been assessable and the functionalization of the finished product, be it either a provisional or a definitive, has been entrusted entirely to the ability of the technician. Case Description: A female patient, unaffected by systemic disease and cranio-cervico-mandibular muscular pain, required removal of hopeless residual teeth of the upper arch and substitution with immediately loaded implants using guided surgery. A fully digital technique was performed using specific software to record individual condylar (axiography) movements and mastication cycles and to correlate these with initial intra-oral scans in order to create a virtual 3D individual value articulator. Seven implants were placed using guided surgery and the prosthetic rehabilitation was successfully performed as planned. Conclusion: The use of guided surgery guarantees atraumaticity and procedure predictability as documented in recent literature. However, in this case, for the first time, using the digital axiograph and digital articulator, it was possible to record the axiography of condylar movements in order to 'functionalize' the diagnostic wax-up prior to its insertion into guided surgery software. This clinical case suggests how the software's compatibility with intra-oral scan files, diagnostic wax-up, facial scans, CBCT and, in the near future, electromyography of mastication muscles permits the clinician to work on a virtual patient and analyze all critical aesthetic and functional parameters prior to guided surgery.