TiAl alloys are lightweight, show decent corrosion resistance and have good mechanical properties at elevated temperatures, making them appealing for high-temperature applications. However, polysynthetic twinned TiAl single crystals fabricated by crystal-seeding methods face substantial challenges, and their service temperatures cannot be raised further. Here we report that Ti-45Al-8Nb single crystals with controlled lamellar orientations can be fabricated by directional solidification without the use of complex seeding methods. Samples with 0° lamellar orientation exhibit an average room temperature tensile ductility of 6.9% and a yield strength of 708 MPa, with a failure strength of 978 MPa due to the formation of extensive nanotwins during plastic deformation. At 900 °C yield strength remains high at 637 MPa, with 8.1% ductility and superior creep resistance. Thus, this TiAl single-crystal alloy could provide expanded opportunities for higher-temperature applications, such as in aeronautics and aerospace.

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By removing a part of the structure, the tooth preparation provides restorative space, bonding surface, and finish line for various restorations on abutment. Preparation technique plays critical role in achieving the optimal result of tooth preparation. With successful application of microscope in endodontics for >30 years, there is a full expectation of microscopic dentistry. However, as relatively little progress has been made in the application of microscopic dentistry in prosthodontics, the following assumptions have been proposed: Is it suitable to choose the tooth preparation technique under the naked eye in the microscopic vision? Is there a more accurate preparation technology intended for the microscope? To obtain long-term stable therapeutic effects, is it much easier to achieve maximum tooth preservation and retinal protection and maintain periodontal tissue and oral function health under microscopic vision? Whether the microscopic prosthodontics is a gimmick or a breakthrough in obtaining an ideal tooth preparation should be resolved in microscopic tooth preparation. This article attempts to illustrate the concept, core elements, and indications of microscopic minimally invasive tooth preparation, physiological basis of dental pulp, periodontium and functions involved in tool preparation, position ergonomics and visual basis for dentists, comparison of tooth preparation by naked eyes and a microscope, and comparison of different designs of microscopic minimally invasive tooth preparation techniques. Furthermore, a clinical protocol for microscopic minimally invasive tooth preparation based on target restorative space guide plate has been put forward and new insights on the quantity and shape of microscopic minimally invasive tooth preparation has been provided.

The virtual patient, a unique computer simulation of the patient's face, teeth, oral mucosa, and bone, provides an extraordinary mechanism for digital dental implant surgery planning and prosthetic design. However, the seamless registration of digital scans with functional information in the context of a virtual articulator remains a challenge. This report describes the treatment of a 47‐year‐old male with full‐mouth guided immediate implant placement and immediate loading of CAD/CAM interim prostheses. Utilizing a novel digital workflow, a multifactorial registration of the vertical dimension of occlusion, centric occlusion, and facebow record were completed digitally and paired within a digital articulator. Utilizing this innovative approach, a complex treatment plan and procedure was executed smoothly with a successful prosthetic outcome demonstrating good fit, occlusion, esthetics, and patient reported satisfaction.

Objective To compare the accuracy of computer‐guided surgery and freehand surgery on flapless immediate implant placement (IIP) in the anterior maxilla. Material and Methods In this split‐mouth design, 24 maxillary incisors in eight human cadaver heads were randomly divided into two groups: computer‐guided surgery (n = 12) and freehand surgery (n = 12). Preoperatively, cone‐beam computed tomography (CBCT) scans were acquired, and all implants were planned with a software (Blue Sky Plan3). Then, two types of surgeries were performed. To assess any differences in position, the postoperative CBCT was subsequently matched with the preoperative planning. For all the implants, the angular, global, depth, bucco‐lingual, and mesio‐distal deviations between the virtual and actual implant positions were measured. Results A significant lower mean angular deviation (3.11 ± 1.55°, range: 0.66–4.95, p = 0.002) and the global deviation at both coronal (0.85 ± 0.38 mm, range: 0.42–1.51, p = 0.004) and apical levels (0.93 ± 0.34 mm, range: 0.64–1.72, p < 0.001) were observed in the guided group when compared to the freehand group (6.78 ± 3.31°, range: 3.08–14.98; 1.43 ± 0.49 mm, range: 0.65–2.31, and 2.2 ± 0.79 mm, range: 1.01–4.02). However, the accuracy of these two approaches was similar for the depth (p = 0.366). In the buccal direction, the mean deviations of both groups showed a general tendency of implants to be positioned facially, occurring more in implants of the freehand group. Conclusion In flapless IIP, computer‐guided surgery showed superior accuracy than freehand surgery in transferring the implant position from the planning. However, even with the help of a guide, the final fixture position tends to shift toward a facial direction.

Parkinson's disease (PD) is a neurodegenerative disorder characterized by progressive cell loss, largely confined to mesencephalic dopamine neurons of the substantia nigra. This study investigated the functional relevance of the HOX transcript antisense intergenic RNA (HOTAIR)/microRNA-221-3 (miR-221-3p)/neuronal pentraxin II (NPTX2) axis in the process of dopaminergic neuron autophagy using PD mouse models. The PD mouse models were established by intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyrindine (MPTP), while PD cell model was constructed by pretreatment with 1-methyl-4-phenylpyridinium (MPP +). The expression of HOTAIR was then examined using RT-qPCR. In addition, the interactions between HOTAIR, miR-221-3p, and NPTX2 were detected through RIP and dual-luciferase reporter gene assays. CCK-8 assay was performed to measure cell viability, and the expression of autophagy-related genes was determined using Western blot analysis. HOTAIR was found to be significantly expressed in the substantia nigra compact tissues and MN9D cells following PD modeling. HOTAIR could bind to miR-221-3p and elevate the NPTX2 expression, which resulted in diminished cell viability and enhanced autophagy of dopaminergic neurons both in vitro and in vivo. In summary, down-regulation of HOTAIR could potentially inhibit the autophagy of dopaminergic neurons in the substantia nigra compacta in a mouse model of PD, thus saving the demise of dopaminergic neurons. .

Objective: This article describes a digital dental esthetic ceramic veneer treatment workflow using a stereolithographic template for teeth preparation. Clinical Considerations: We have presented the case of a 33-year-old woman with dental fluorosis who wanted an esthetic ceramic veneer treatment. A digital smile design was created on a virtual patient, and a virtual diagnostic wax-up was made. Based on the suggested ceramic material thickness, virtual teeth preparation was performed on the diagnostic wax-up. A special-teeth preparation template was then created digitally and fabricated using a stereolithographic technique. This template guided the teeth preparation using a special bur with a stopper. The veneers were fabricated by CAD/CAM and delivered good esthetics and function. Conclusions: The stereolithographic tooth reduction template helps realize digital restorative planning. It provides better control of the reduction depth of the labial and incisal preparation, making the operation simpler. Clinical significance: The digital dental esthetic ceramic veneer treatment workflow described here using a stereolithographic template for teeth preparation helped with the accurate control of reduction depth for minimally invasive teeth preparation, making the operation simpler, which is a significant improvement over the previous methods.

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