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Purpose: To evaluate the accuracy of guiding plane preparation for removable partial dentures (RPDs) using 3D‐printed templates compared to the freehand method. Materials and Methods: Twenty partially edentulous patients requiring RPDs were randomly divided into two groups: the template‐aided group (n = 10) and the freehand group (n = 10). Fifty‐six guiding planes were prepared by a single clinician using two different methods. The angle deviation between the prepared guiding plane and the RPD path of placement was measured for both groups. The 3D deviations between the prepared guiding plane and the designed guiding plane were measured for the template‐aided group. Patient satisfaction with the RPD was evaluated 2 weeks post‐RPD wearing. Results: The angular deviation observed in the template‐aided group (1.77±1.11 degrees) was significantly lower than that (6.29±4.18 degrees) in the freehand group (p <.001). Additionally, the 3D deviation between the prepared guiding plane and the designed guiding plane of the template‐aided group was 106.2±40.9 µm. No significant difference in patient satisfaction scores related to RPD wearing was found between the two groups. Conclusions: Utilizing the cobalt‐chromium (CoCr) alloy template significantly improved the accuracy of guiding plane preparation in the clinic, irrespective of the site of the abutment tooth. [ABSTRACT FROM AUTHOR]

Purpose: To explore the clinical application of one‐piece polyetheretherketone (PEEK) removable partial dentures (RPDs) fabricated using a novel digital workflow and to evaluate their weights and fits in vivo and patient satisfaction. Materials and Methods: Fifteen cases with posterior partially edentulous situations were selected, and each patient received two types of RPDs, including a novel digital workflow (test group) and a conventional workflow (control group). For the test group, one‐piece RPDs were designed through three‐dimensional (3D) methods by scanning stone casts and fabricated by milling PEEK discs. Each RPD was weighed. The gaps between the oral tissue and RPDs in each group were duplicated using a polyvinylsiloxane (PVS) replica and measured by 3D analysis. A visual analog scale (VAS) was used to evaluate the patient's satisfaction. Paired t‐tests were used to compare the differences in the weight, the gaps of each RPD, and VAS values between the two groups. One‐way analysis of variance tests was used to compare the differences in the gap among different components in each group. Results: The RPD in the test group weighed less than that in the control group (p < 0.01). No statistically significant differences in the gaps of denture bases and rests (p > 0.05) were found between the two groups, but the gaps of major connectors in the test group were significantly smaller than in the control group (p < 0.05). The VAS scores for comfortableness and masticatory efficiency were not significantly different between the two groups (p > 0.05) but the scores for the aesthetic appearance of the clasps in the test group were significantly higher than that in the control group (p < 0.05). Conclusions: One‐piece PEEK RPDs manufactured using a novel digital workflow weighed less than conventional RPDs and exhibited a clinically acceptable internal fit. Although the aesthetic appearance of the PEEK clasps was superior to the control, there is still room for improvement. [ABSTRACT FROM AUTHOR]

Reducing the diameter of silver nanowires has been proven to be an effective way to improve their optoelectronic performance by lessening light attenuation. The state-of-the-art silver nanowires are typically around 20 nm in diameter. Herein we report a modified polyol synthesis of silver nanowires with average diameters as thin as 13 nm and aspect ratios up to 3000. The success of this synthesis is based on the employment of benzoin-derived radicals in the polyol approach and does not require high-pressure conditions. The strong reducing power of radicals allows the reduction of silver precursors to occur at relatively low temperatures, wherein the lateral growth of silver nanowires is restrained because of efficient surface passivation. The optoelectronic performance of as-prepared 13 nm silver nanowires presents a sheet resistance of 28 Ω sq-1 at a transmittance of 95% with a haze factor of ∼1.2%, comparable to that of commercial indium tin oxide (ITO).

Copper nanowire networks are considered a promising alternative to indium tin oxide as transparent conductors. The fast degradation of copper in ambient conditions, however, largely overshadows their practical applications. Here, we develop the synthesis of ultrathin Cu@Au core-shell nanowires using trioctylphosphine as a strong binding ligand to prevent galvanic replacement reactions. The epitaxial overgrowth of a gold shell with a few atomic layers on the surface of copper nanowires can greatly enhance their resistance to heat (80 °C), humidity (80%) and air for at least 700 h, while their optical and electrical performance remained similar to the original high-performance copper (e.g., sheet resistance 35 Ω sq-1 at transmittance of ∼89% with a haze factor

In this work, we report a new, general synthetic approach that uses heat driven benzoin radicals to grow ultrathin copper nanowires with tunable diameters. This is the first time carbon organic radicals have been used as a reducing agent in metal nanowire synthesis. In-situ temperature dependent electron paramagnetic resonance (EPR) spectroscopic studies show that the active reducing agent is the free radicals produced by benzoins under elevated temperature. Furthermore, the reducing power of benzoin can be readily tuned by symmetrically decorating functional groups on the two benzene rings. When the aromatic rings are modified with electron donating (withdrawing) groups, the reducing power is promoted (suppressed). The controllable reactivity gives the carbon organic radical great potential as a versatile reducing agent that can be generalized in other metallic nanowire syntheses.

Copper is uniquely active for the electrocatalytic reduction of carbon dioxide (CO2) to products beyond carbon monoxide, such as methane (CH4) and ethylene (C2H4). Therefore, understanding selectivity trends for CO2 electrocatalysis on copper surfaces is critical for developing more efficient catalysts for CO2 conversion to higher order products. Herein, we investigate the electrocatalytic activity of ultrathin (diameter ∼20 nm) 5-fold twinned copper nanowires (Cu NWs) for CO2 reduction. These Cu NW catalysts were found to exhibit high CH4 selectivity over other carbon products, reaching 55% Faradaic efficiency (FE) at -1.25 V versus reversible hydrogen electrode while other products were produced with less than 5% FE. This selectivity was found to be sensitive to morphological changes in the nanowire catalyst observed over the course of electrolysis. Wrapping the wires with graphene oxide was found to be a successful strategy for preserving both the morphology and reaction selectivity of the Cu NWs. These results suggest that product selectivity on Cu NWs is highly dependent on morphological features and that hydrocarbon selectivity can be manipulated by structural evolution or the prevention thereof.

Objective: This study aimed to present three indicators that represent the proximal contact area gap change under intercuspal occlusion and to see if and how these indicators influence food impaction with tight proximal contact. Materials and Methods: Ninety volunteers were recruited for bite force measurement and intraoral scanning. Three‐dimensional surface data and buccal bite data were obtained for 60 impacted and 60 non‐impacted teeth. The scanning data were imported into the Geomagic Studio 2013 to measure three indicators, which included the gap change maximum (Δdm, μm), the buccolingual position of Δdm (P), and the gap expanded buccolingual range (S, mm). The difference between two groups of three indicators and their relationship with food impaction with tight proximal contact were analyzed by the t test, the Pearson chi‐squared test, the nonparametric Mann–Whitney U test, and the binary logistic regression analysis (a = 0.05). Results: All indicators (Δdm, P, and S) were statistically different (p < 0.001, p = 0.002, and p < 0.001) in the impacted and non‐impacted groups. Food impaction with tight proximal contact was affected by Δdm and S (p < 0.001, p = 0.039), but not by P (p = 0.409). Conclusion: The excessive increase of the gap change maximum and the gap expanded buccolingual range under bite force promoted the occurrence of food impaction with tight proximal contact. Clinical Significance: The use of intraoral scanning to measure the characteristics of the proximal contact area gap change under bite force may help to deepen our understanding of the pathogenesis of food impaction with tight proximal contact. Importantly it can provide a reference basis for individualizing and quantifying occlusal adjustment treatment. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to develop a structured light scanning system with a planar mirror to enhance the digital full‐arch implant impression accuracy and to compare it with photogrammetry and intraoral scanner methods. Materials and Methods: An edentulous maxillary stone cast with six scan bodies was scanned as the reference model using a laboratory scanner. Three scanning modalities were compared (n = 10): (1) self‐developed structured light scanning with a mirror (SSLS); (2) intraoral scanner (IOS); and (3) photogrammetry system (PG). The scanners were stopped for 1 min after each scan. Six scan bodies were analysed within each scan model. Linear deviations between the scan bodies (1–2, 1–3, 1–4, 1–5, and 1–6) and 3D mucosal deviations were established. The overall deviation was calculated as the mean of all linear deviations. "Trueness" represented the discrepancy between the test and reference files, while "precision" denoted the consistency among the test files. Kruskal–Wallis and Mann–Whitney U tests were used for statistical analyses. Results: Significant overall linear discrepancies were noted among the SSLS, PG, and IOS groups (p <.001). SSLS showed the best overall trueness and precision (6.6, 5.7 μm), followed by PG (58.4, 6.8 μm) and IOS (214.6, 329.1 μm). For the 3D mucosal deviation, the trueness (p <.001) and precision (p <.001) of the SSLS group were significantly better than those of the IOS group. Conclusions: The SSLS exhibited higher accuracy in determining the implant positions than the PG and IOS. Additionally, it demonstrated better accuracy in capturing the mucosa than IOS. [ABSTRACT FROM AUTHOR]