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Background: Maintaining a long-term biological effect of dental materials on dentinal tubule occlusion is one of the great technical challenges in dental clinics. In addition to physical treatment, chemical treatment to produce insoluble precipitates to seal dentinal tubules has been used. As dentin is mostly composed of calcium and phosphate complexes, in this study, we have developed a novel tubule-occluding material [Ca 2+ /PO 4 3− @mesoporous silica nanoparticles (MSNs)] by separately conjugating either Ca 2+ or PO 4 3− with MSNs. Methods:The shape and structure of the MSNs were examined using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The surface morphology and chemical compositions of Ca 2+ @MSNs/PO 4 3− @MSNs and Ca 2+ /PO 4 3− @MSNs were examined using SEM and X-ray fluorescence (XRF).The element distribution of Ca 2+ /PO 4 3− @MSNs was detected using energy dispersive spectrometer (EDS).The sustained release ability of Ca 2+ @MSNs/PO 4 3− @MSNs was detected using inductively coupled plasma atomic emission spectrometry (ICP-AES). The efficacy of Ca 2+ /PO 4 3− @MSNs on dentinal tubule sealing was evaluated using SEM, and the results were analyzed by Image-Pro software to determine the best waterpowder ratio. We also compared the sealing efficacy between Ca 2+ /PO 4 3− @MSNs and NovaMin, which is currently used in clinics, under the simulated conditions of oral acidic corrosion and mechanical friction.Results: Ca 2+ /PO 4 3− @MSNs are a new type of tubule-occluding material with sustained release properties.The ratio of Ca 2+ @MSNs: PO 4 3− @MSNs: H 2 O =0.015 g: 0.015 g: 150 μL exhibited an excellent sealing effect on dentinal tubules as well as resistance to oral acid corrosion and daily oral friction. Conclusions:The novel dental material Ca 2+ /PO 4 3− @MSNs demonstrates potential long-term effectiveness in sealing dentinal tubules and reducing dentin sensitivity, which is one of the most important problems in dental clinics.

Generally, foamed epoxy resin prepared by chemical method has relatively large average cell size and low cell density, resulting in low mechanical properties and poor heat resistance. In this work, a new type of composite foaming agent (CFA) was prepared by filling the chemical foaming agent 4,4′‐bisoxybenzenesulfonyl hydrazide (OBSH) into microporous silica microspheres (MSMs), and then used for epoxy resin foaming research. The effects of curing agent diethylenetriamine (DETA) and CFA contents on cell density and size were also discussed. The best epoxy resin foaming sample has a cell density of 106 cells cm−3 with an average cell diameter of 65 μm, and a high compressive strength of 34 MPa as well as a good heat resistance. These results indicate the potential application of CFA in epoxy resin foaming area.

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