Recent studies have highlighted variations in the geometry of teeth prepared to receive metal ceramic crowns, particularly in the region of the labial shoulder, where shoulder designs have often involved less reduction than is recommended. Using two-dimensional finite element analysis, this study subjected crowns, superimposed upon preparations with clinically common labial margin designs, to loads of 200N in three different directions. The resultant stress distribution within the labial marginal porcelain was examined. Results imply that variations in the marginal preparation geometry of metal ceramic crowns influenced the stress response of the finished crown. Within the limits of this study, a crown constructed a 1.3mm chamfer preparation appeared to have the best response to a simulated load applied to the palatal/incisal surface, at 45 degrees to the long axis.
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Nature
January 2025
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China.
Dielectric-based energy storage capacitors characterized with fast charging and discharging speed and reliability play a vital role in cutting-edge electrical and electronic equipment. In pursuit of capacitor miniaturization and integration, dielectrics must offer high energy density and efficiency. Antiferroelectrics with antiparallel dipole configurations have been of significant interest for high-performance energy storage due to their negligible remanent polarization and high maximum polarization in the field-induced ferroelectric state.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
School of Materials Science & Engineering, The Key Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of China, Tianjin University, Tianjin 300072, China.
Rib fracture-related infection is a challenging complication of thoracic trauma due to the difficulty of treating it with antibiotics alone and the need for a second operation to remove the infected fixator and sterilize the surrounding infected tissue. In this study, inspired by the photocatalytic performance of and ion release from silver-based materials, including AgPO and AgS, a hybrid AgPO-AgS heterojunction was prepared based on anion exchange and a one-step calcination process to design a nonantibiotic coating aimed at preventing and treating rib fracture-related infection with short-term 808 nm near-infrared irradiation. Calcination at 250 °C enhanced the inductive effect of the phosphate radical and led to the formation of a tight nanoheterogeneous interface between AgPO and AgS, thereby promoting interfacial electron transfer and reducing the recombination of photogenerated carriers.
View Article and Find Full Text PDFJ Contemp Dent Pract
October 2024
Department of Crown and Bridge, Faculty of Dentistry, Al-Azhar University, Cairo, Egypt.
Aim: To assess hard as well as soft peri-implant tissues within cases having two lost adjacent anterior teeth treated through placing either two implants with two separate crowns or only an implant along with a crown with a cantilever, and evaluating the effect of polyetheretherketone (PEEK) restoration on cantilever design up to 18 months after functional loading.
Materials And Methods: Twenty-seven participants (15 males and 12 females; mean age, 38.6 years; range 20-50 years) with missing two adjacent anterior teeth were treated with implant system (Flotecno implant system, Italy).
Angew Chem Int Ed Engl
January 2025
Shanghai Institute of Ceramics Chinese Academy of Sciences, State Key Laboratory of High Performance Ceramics and Superfine Microstructure, CHINA.
Pairing photocatalytic 1,2,3,4-tetrahydroisoquinoline semi-dehydrogenation reaction (THIQ-SDR) with two-electron oxygen reduction reaction (2e- ORR) is a green solar to chemical strategy by simultaneously utilizing the photo-excited electrons and holes. However, it is still short of high-efficiency photocatalyst to drive two reactions above. In the present work, crystalline pyrene-thiourea/urea covalent organic frameworks (COF-Py-S and -O) were synthesized and demonstrated as high-performance metal-free photocatalysts.
View Article and Find Full Text PDFBMC Oral Health
January 2025
Department of Orthodontics, Faculty of Dentistry, Biruni University, İstanbul, Turkey.
Objective: This study aims to examine color properties of repairs made with various composites on restorations produced through additive-manufactured resin composites (AM-RC) and zirconia (AM-Z) or subtractive manufacturing (SM) after coffee thermocycling (CTC).
Materials And Methods: Disk-shaped specimens (Ø10 × 2 mm; N = 120) were fabricated using six different material groups: additively manufactured resin composite (AM-RC) materials (Crowntec [C], NextDent [ND]), additively manufactured zirconia (AM-Z) materials (Lithoz [LI], INNI-Cera [IN]), and subtractively manufactured (SM) materials (CEREC Tessera [ALD], Vita Enamic [EN]). Subsequently, each group was further subdivided into two subgroups (n = 10) based on the type of repair using two different composites resins: Clearfil Majesty Posterior (CL) (n = 60) and Filtek Z350 (FZ) (n = 60).
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