Introduction: The objectives of this study were to determine the effects of various surface conditioning methods on 3 types of ceramic materials (feldsphatic, leucite-based, and lithia disilicate-based) in orthodontic bonding.
Methods: A total of 210 ceramic disk samples were fabricated and divided into 3 groups. In each group, 5 subgroups were prepared by sandblasting; sandblasting and hydrofluoric (HF) acid; sandblasting and silane; sandblasting, HF acid, and silane; and tribochemical silica coating and silane. Mandibular incisor brackets were bonded with light-cured adhesive. The samples were stored in water for 24 hours at 37 degrees C and then thermocycled. Shear bond tests were performed, and the failure types were classified with adhesive remnant index scores.
Results: In all 3 ceramic groups, the lowest shear bond strength values were found in the sandblasted-only samples. For the feldspathic and lithia disilicate-based ceramic, the highest bond strength values were obtained with silica coating (15.2 and 13.2 MPa, respectively). For the leucite-based ceramic, HF without silane produced the highest bond strength value (14.7 MPa), but comparable values were obtained with silicatization also (13.4 MPa).
Conclusions: The silica-coating technique could replace the other conditioning techniques in bonding brackets to ceramic. However, debonding must be done carefully because of the risk of porcelain fracture.
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http://dx.doi.org/10.1016/j.ajodo.2006.12.006 | DOI Listing |
J Comput Chem
January 2025
Department of Inorganic Chemistry, Faculty of Chemistry and Petroleum Sciences, Bu-Ali Sina University, Hamedan, Iran.
The strength and cooperative energy of chalcogen and dihydrogen bonds in some ABC triad systems of the types XHTe…NCH…HY (X = F, Cl, Br, I, H; Y = Li, Na, BeH, MgH) and FHCh…NCH…HNa (Ch = Te, Se, S) were computed and compared at several levels of theory. All resulting data showed that the strengths of chalcogen (Te…N) and dihydrogen (H…H) bonds increase in the order of H < I < Br < Cl < F, and Be < Mg < Li < Na, respectively. Then, the comparison of data for the FHTe…NCH…HY, FHSe…NCH…HNa, and FHS…NCH…HNa triads indicated that the interaction, stabilization, and cooperativity energies decrease in the order of Te > Se > S.
View Article and Find Full Text PDFSci Bull (Beijing)
January 2025
Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Hubei Provincial Engineering Research Center of Emerging Functional Coating Materials, School of Resource and Environmental Sciences, Wuhan University, Wuhan 430079, China. Electronic address:
The discontinuous fiber reinforced hydrogels are easy to fail due to the fracture of the fiber matrix during load-bearing. Here, we propose a novel strategy based on the synergistic reinforcement of interconnected natural fiber networks at multiple scales to fabricate hydrogels with extraordinary mechanical properties. Specifically, the P(AA-AM)/Cel (P(AA-AM), poly(acrylic acid-acrylamide); Cel, cellulose) hydrogel is synthesized by copolymerizing AA and AM on a substrate of paper with an interconnected hollow cellulose microfiber network.
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January 2025
School of Civil Engineering and Environmental Science, University of Oklahoma, 202 W Boyd St., Norman, OK 73019, USA.
With 3D printing technology, fiber-reinforced polymer composites can be printed with radical shapes and properties, resulting in varied mechanical performances. Their high strength, light weight, and corrosion resistance are already advantages that make them viable for physical civil infrastructure. It is important to understand these composites' behavior when used in concrete, as their association can impact debonding failures and overall structural performance.
View Article and Find Full Text PDFPolymers (Basel)
January 2025
Department of Materials and Applied Chemistry, College of Science and Technology, Nihon University, 1-8-14 Kandasurugadai, Chiyoda-ku, Tokyo 101-8308, Japan.
Calcified tissues in living organisms, such as bone, dentin, and enamel, often require surgical intervention for treatment. However, advances in regenerative medicine have increased the demand for materials to assist in regenerating these tissues. Among the various forms of calcium phosphate (CaP), tricalcium phosphate (TCP)-particularly its α-TCP form-stands out due to its high solubility and efficient calcium release, making it a promising candidate for bone regeneration applications.
View Article and Find Full Text PDFMolecules
January 2025
Institute for Preservation and Conservation of Chinese Ancient Books, Fudan University Library, Fudan University, 220 Handan Road, Shanghai 200433, China.
Paper-based cultural relics experience aging and deterioration during their long-term preservation, which poses a serious threat to their lifetime. The development of conservation materials with high compatibility and low intervention has been expected to extend the lifetime of paper artifacts. As a new type of biological macromolecule, nanocellulose has been extensively utilized in paper conservation, attributed to its excellent paper compatibility, high optical transparency, outstanding mechanical strength, and large specific surface area with abundant hydroxyl groups.
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