摘要:
The present invention concerns the preparation of chemically modified derivatives of chitosan with acrylic groups and their use in the field of enamel-dentin adhesives. Chitosan derivatives have physical-chemical features (hydrophilicity, presence of electrical charges on the chain) which allow them to interact with the organic part of the demineralized tooth. At the same time, the acrylic groups incorporated in the polymer chain allow the formation of a covalent bond with the restorative material used in the dental field that is typically composed of acrylic resins. By combining the adhesion to the tooth surface and the bond with the restorative material, the chemically modified chitosan described herein is able to increase the lifespan of the dental restoration and can thus find use in the field of adhesives, in particular enamel-dentin adhesives.
摘要:
Methods for removing endotoxin from naturally occurring materials, such as polysaccharides (e.g., agarose and/or carrageenan) are described herein. Polysaccharides that are substantially free of endotoxins and uses thereof are also described. The polysaccharide materials can be isolated from microorganisms, multicellular organisms, such as, algae, plants, seaweed, etc. The method involves the use of acidic and basic solutions to hydrolyze the lipid-polysaccharide bond in endotoxins. Cleaving the fatty acid from the polysaccharide reduces the water-solubility of the fatty acid and enables its removal with an organic solvent such as ethanol. The polysaccharide component can also undergo acidic or basic hydrolysis due to the weak glycosidic bond between the sugar rings.
摘要:
The invention relates to a curable dental retraction composition comprising alginate and a solvent, with the proviso that essentially no crosslinker in an amount effective to start setting of the curable dental retraction composition is present. The invention also relates to a container containing said composition and to a kit comprising two parts, wherein the first part comprises the curable dental retraction composition of the present invention and the second part comprises a crosslinker being able to start setting of the dental retraction composition.
摘要:
Improved compositions comprising a mixture of particulate bone growth material and polymeric carrier are provided. The particulate is preferably porous, resorbable, anorganic bone material. The polymeric carrier can be light-cured to form a cross-linked, biodegradable hydrogel. In one version, the bone growth material is a synthetic peptide bound to anorganic bone matrix particles and the carrier is methacrylated sodium hyaluronate (MHy) or methacrylated hydroxyethylcellulose (MHEC). The composition is particularly suitable for repairing defective dental and orthopedic bone tissue. The particulate and hydrogel carrier are biodegradable so the composition can be replaced by new bone formation over time.
摘要:
A bone or dental implant material in the form of a paste includes a mixture of calcium phosphate and/or calcium-containing powders and a solution that is (1) an acidic calcium phosphate solution saturated with respect to one or more calcium phosphate compounds, (2) a concentrated acid solution, or (3) salt solutions with a cationic component other than calcium. The paste is stable, resistant to washout and will form hydroxyapatite and harden relatively rapidly to a cement.
摘要:
An injectable and moldable putty comprising biodegradable calcium-based compounds including calcium sulfate, hydroxyapatite, and tricalcium phosphate is invented. The putty hardens into a solid body when mixed with water, saline, serum, or other neutral aqueous solutions. The hardening time of the putty can be tailored in order to meet the specific requirements of various dental or orthopedic applications. The pH of the putty is neutral during and after mixing. The invented putty may be used as bone graft, bone implant, or implantable drug delivery device.
摘要:
Compounds of the formula I R1 and R2 independently of one another are C1-C20alkyl, OR11, CF3 or halogen; R3, R4 and R5 independently of one another are hydrogen, C1-C20alkyl, OR1 or halogen; R6, R7, R8, R9 and R10 independently of one another are hydrogen, C1-C20alkyl; C2-C20alkyl which is interrupted once or more than once by nonconsecutive O atoms and which is unsubstituted or substituted by OH and/or SH; or R6, R7, R8, R9 and R10 are OR11, SR11, N(R12)(R13), phenyl or halogen; R11 is C1-C20alkyl, C3-C8cycloalkyl, phenyl, benzyl or C2-C20alkyl which is interrupted once or more than once by O or S and which is unsubstituted or substituted by OH and/or SH; R12 and R13 independently of one another are hydrogen, C1-C20alkyl, C3-C8cycloalkyl, phenyl, benzyl or C2-C20alkyl which is interrupted once or more than once by nonconsecutive O atoms and which is unsubstituted or substituted by OH and/or SH; or R12 and R13 together are C3-C5alkylene which can be interrupted by O, S or NR14; R14 is hydrogen, phenyl, C1-C12alkyl or C2-C12alkyl which is interrupted once or more than once by O or S and which is unsubstituted or substituted by OH and/or SH; and M is hydrogen, Li, Na or K; are valuable intermediates for the preparation of unsymmetrical bisacylphosphine oxides and monoacylphosphine oxides.
摘要:
Methods are provide for producing flowable compositions, e.g. pastes, that set into calcium phosphate products. In the subject methods, dry reactants that include a calcium source and a phosphate source are combined with a solution of a soluble silicate, e.g. sodium silicate, and the combined liquids and solids are mixed to produce the flowable composition. Also provided are the compositions themselves as well as kits for preparing the same. The subject methods and compositions produced thereby find use in a variety of applications, including the repair of hard tissue defects, e.g. bone defects.
摘要:
1 R1 and R2 independently of one another are C1-C20alkyl, OR11, CF3 or halogen; R3, R4 and R5 independently of one another are hydrogen, C-C20alkyl, OR11 or halogen; R6, R7, R8, R9 and R10 independently of one another are hydrogen, C1-C20alkyl; C2-C20alkyl which is interrupted once or more than once by nonconsecutive O atoms and which is unsubstituted or substituted by OH and/or SH; or R6, R7, R8, R9 and R10 are OR11, SR11, N(R12)(R13), phenyl or halogen; R11 is C1-C20alkyl, C3-C8cycloalkyl, phenyl, benzyl or C2-C20alkyl which is interrupted once or more than once by O or S and which is unsubstituted or substituted by OH and/or SH; R12 and R13 independently of one another are hydrogen, C1-C20alkyl, C3-C8cycloalkyl, phenyl, benzyl or C2-C20alkyl which is interrupted once or more than once by nonconsecutive O atoms and which is unsubstituted or substituted by OH and/or SH; or R12 and R13 together are C3-C5alkylene which can be interrupted by O, S or NR14; R14 is hydrogen, phenyl, C1-C12alkyl or C2-C12alkyl which is interrupted once or more than once by O or S and which is unsubstituted or substituted by OH and/or SH; and M is hydrogen, Li, Na or K; are valuable intermediates for the preparation of unsymmetrical bisacylphosphine oxides and monoacylphosphine oxides.