A study has been made of the effects of sandblasting on the strength of Y-TZP and alumina ceramic layers joined to polymeric substrates and loaded at the top surfaces by a spherical indenter, in simulation of occlusal contact in ceramic crowns on tooth dentin. The sandblast treatment is applied to the ceramic bottom surface before bonding to the substrate, as in common dental practice. Specimens with polished surfaces are used as a control. Tests are conducted with monotonically increasing (dynamic) and sinusoidal (cyclic) loading on the spherical indenter, up to the point of initiation of a radial fracture at the ceramic bottom surface immediately below the contact. For the polished specimens, data from the dynamic and cyclic tests overlap, consistent with a dominant slow crack growth mode of fatigue. Strengths of sandblasted specimens show significant reductions in both dynamic and cyclic tests, indicative of larger starting flaws. However, the shift is considerably greater in the cyclic data, suggesting some mechanically assisted growth of the sandblast flaws. These results have implications in the context of lifetimes of dental crowns.

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Objective Test the hypothesis that monolithic ceramics can be developed with combined esthetics and superior fracture resistance to circumvent processing and performance drawbacks of traditional all-ceramic crowns and fixed-dental-prostheses consisting of a hard and strong core with an esthetic porcelain veneer. Specifically, to demonstrate that monolithic prostheses can be produced with a much reduced susceptibility to fracture. Methods Protocols were applied for quantifying resistance to chipping as well as resistance to flexural failure in two classes of dental ceramic, microstructurally-modified zirconias and lithium disilicate glass–ceramics. A sharp indenter was used to induce chips near the edges of flat-layer specimens, and the results compared with predictions from a critical load equation. The critical loads required to produce cementation surface failure in monolithic specimens bonded to dentin were computed from established flexural strength relations and the predictions validated with experimental data. Results Monolithic zirconias have superior chipping and flexural fracture resistance relative to their veneered counterparts. While they have superior esthetics, glass–ceramics exhibit lower strength but higher chip fracture resistance relative to porcelain-veneered zirconias. Significance The study suggests a promising future for new and improved monolithic ceramic restorations, with combined durability and acceptable esthetics.

Ultralong cycle life, high energy, and power density rechargeable lithium‐ion batteries are crucial to the ever‐increasing large‐scale electric energy storage for renewable energy and sustainable road transport. However, the commercial graphite anode cannot perform this challenging task due to its low theoretical capacity and poor rate‐capability performance. Metal oxides hold much higher capacity but still are plagued by low rate capability and serious capacity degradation. Here, a novel strategy is developed to prepare binder‐free and mechanically robust CoO/graphene electrodes, wherein homogenous and full coating of β‐Co(OH)2 nanosheets on graphene, through a novel electrostatic induced spread growth method, plays a key role. The combined advantages of large 2D surface and moderate inflexibility of the as‐obtained β‐Co(OH)2/graphene hybrid enables its easy coating on Cu foil by a simple layer‐by‐layer stacking process. Devices made with these electrodes exhibit high rate capability over a temperature range from 0 to 55 °C and, most importantly, maintain excellent cycle stability up to 5000 cycles even at a high current density.