Patents by Inventor Laurence C. Chow

Laurence C. Chow has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8282396
    Abstract: A bone or dental implant material in the form of a paste includes a mixture of calcium phosphate and/or calcium-containing powders, liquid glycerol, organic acid and gelling agent. The paste is stable, resistant to washout and will harden upon exposure to water. Physical characteristics of the paste, including consistency, porosity, and hardening time, are controlled by the choice and ratio of constituents.
    Type: Grant
    Filed: May 3, 2010
    Date of Patent: October 9, 2012
    Assignee: ADA Foundation
    Inventors: Laurence C. Chow, Shozo Takagi
  • Publication number: 20120217665
    Abstract: A method for preparing uniquely sized nanoparticles of CaF2 by simultaneously spray drying a first NH4F and a biocompatible salt solution and a second Ca(OH)2 and biocompatible salt solution to form CaF2 solid particles in a soluble salt matrix wherein the salt is more soluble than CaF2. The salt matrix may then be dissolved and the separate CaF2 nanosized particles collected for use as a dental therapeutic material. The technique is useful in the preparation of other discrete, nanoparticle sized compounds and combinations by carefully choosing the solvents and solutes of the two spray dried solutions.
    Type: Application
    Filed: February 27, 2012
    Publication date: August 30, 2012
    Applicant: ADA Foundation
    Inventors: Laurence C. Chow, Limin Sun
  • Publication number: 20120000393
    Abstract: This study reports in vitro and in vivo properties of fluorapatite (FA)-forming calcium phosphate cements (CPCs). Experimental cements contained from (0 to 3.1) mass % of F, corresponding to presence of FA at levels of approximately (0 to 87) mass %. The crystallinity of the apatitic cement product increased greatly with the FA content. When implanted subcutaneously in rats, the in vivo resorption rate decreased significantly with increasing FA content. The cement with the highest FA content was not resorbed in soft tissue, making it biocompatible and bioinert CPC. These bioinert CPCs are candidates for use in useful applications where slow or no resorption of the implant is required to achieve the desired clinical outcome.
    Type: Application
    Filed: July 1, 2011
    Publication date: January 5, 2012
    Applicant: ADA Foundation a not-for-profit corporation of Illinois
    Inventors: Laurence C. Chow, Shozo Takagi
  • Publication number: 20100269736
    Abstract: Disclosed are dual-phase cement precursor systems and associated methods and kits. The cement precursor systems comprises at least first and second phases each containing a calcium phosphate compound. When mixed, the first and second cement precursor phases form a biocompatible cement. The disclosed systems include an organic acid in an amount effective to enhance the working time of the cement precursor composition, and also include a setting accelerator. In some embodiments, one or more of the calcium phosphate compounds is provided in the form of particles with a nonmonomial particle sized distribution.
    Type: Application
    Filed: April 22, 2010
    Publication date: October 28, 2010
    Applicant: American Dental Association Foundation
    Inventors: Laurence C. Chow, Shozo Takagi
  • Publication number: 20100212545
    Abstract: A bone or dental implant material in the form of a paste includes a mixture of calcium phosphate and/or calcium-containing powders, liquid glycerol, organic acid and gelling agent. The paste is stable, resistant to washout and will harden upon exposure to water. Physical characteristics of the paste, including consistency, porosity, and hardening time, are controlled by the choice and ratio of constituents.
    Type: Application
    Filed: May 3, 2010
    Publication date: August 26, 2010
    Applicant: ADA Foundation
    Inventors: Laurence C. Chow, Shozo Takagi
  • Patent number: 7709029
    Abstract: A bone or dental implant material in the form of a paste includes a mixture of calcium phosphate and/or calcium-containing powders, liquid glycerol, organic acid and gelling agent. The paste is stable, resistant to washout and will harden upon exposure to water. Physical characteristics of the paste, including consistency, porosity, and hardening time, are controlled by the choice and ratio of constituents.
    Type: Grant
    Filed: March 11, 2004
    Date of Patent: May 4, 2010
    Assignee: ADA Foundation
    Inventors: Laurence C. Chow, Shozo Takagi
  • Patent number: 7670579
    Abstract: Nano-particles of calcium and phosphorous compounds are made in a highly pure generally amorphous state by spray drying a weak acid solution of said compound and evaporating the liquid from the atomized spray in a heated column followed by collection of the precipitated particles. Hydroxyapatite (HA) particles formed by such apparatus and methods are examples of particle manufacture useful in bone and dental therapies. Dual nozzle spraying techniques are utilized for generally insoluble compounds.
    Type: Grant
    Filed: September 16, 2005
    Date of Patent: March 2, 2010
    Assignee: American Dental Association Foundation
    Inventors: Laurence C. Chow, Limin Sun
  • Patent number: 7632878
    Abstract: Combining nanosized particles of a source of desired dental restorative, repair or therapeutic materials with strengthening agents in various generally nanosized form such as whiskers, fibers, particles and the like in a resin matrix provides a highly strain resistant composite which more effectively releases the therapeutic agents. The utilization of nano sized particles of the therapeutic agent in the combination enables observation of significantly improved therapeutic results.
    Type: Grant
    Filed: October 17, 2008
    Date of Patent: December 15, 2009
    Assignee: American Dental Association Foundation
    Inventors: Huakun Xu, Limin Sun, Shozo Takagi, Laurence C. Chow
  • Publication number: 20090093566
    Abstract: Combining nanosized particles of a source of desired dental restorative, repair or therapeutic materials with strengthening agents in various generally nanosized form such as whiskers, fibers, particles and the like in a resin matrix provides a highly strain resistant composite which more effectively releases the therapeutic agents. The utilization of nano sized particles of the therapeutic agent in the combination enables observation of significantly improved therapeutic results.
    Type: Application
    Filed: October 17, 2008
    Publication date: April 9, 2009
    Applicant: ADA Foundation
    Inventors: Huakun Xu, Limin Sun, Shozo Takagi, Laurence C. Chow
  • Publication number: 20090035378
    Abstract: Nano-particles of calcium and phosphorous compounds are made in a highly pure generally amorphous state by spray drying a weak acid solution of said compound and evaporating the liquid from the atomized spray in a heated column followed by collection of the precipitated particles. Hydroxyapatite (HA) particles formed by such apparatus and methods are examples of particle manufacture useful in bone and dental therapies. Dual nozzle spraying techniques are utilized for generally insoluble compounds.
    Type: Application
    Filed: September 16, 2008
    Publication date: February 5, 2009
    Applicant: American Dental Association Foundation
    Inventors: Laurence C. Chow, Limin Sun
  • Patent number: 7390335
    Abstract: Nano-particles of calcium and phosphorous compounds are made in a highly pure generally amorphous state by spray drying a weak acid solution of said compound and evaporating the liquid from the atomized spray in a heated column followed by collection of the precipitated particles. Hydroxy apetite (HA) particles formed by such apparatus and methods are examples of particle manufacture useful in bone and dental therapies.
    Type: Grant
    Filed: April 6, 2005
    Date of Patent: June 24, 2008
    Assignee: American Dental Association Foundation
    Inventor: Laurence C. Chow
  • Patent number: 7294187
    Abstract: 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.
    Type: Grant
    Filed: September 15, 2004
    Date of Patent: November 13, 2007
    Assignee: ADA Foundation
    Inventors: Laurence C. Chow, Shozo Takagi
  • Patent number: 7018460
    Abstract: A bone replacement material and therapy comprises the combination of calcium phosphate compounds and two or more soluble fillers in the form of fibers, mesh or other materials which have the dual functions of reinforcing an in vivo implant while dissolving at a programmed rate to form macropores capable of receiving natural bone ingrowth.
    Type: Grant
    Filed: October 28, 2004
    Date of Patent: March 28, 2006
    Assignee: American Dental Association Health Foundation
    Inventors: Huakun Xu, Laurence C. Chow, Shozo Takagi, Frederick C. Eichmiller
  • Patent number: 6955716
    Abstract: A bone replacement material and therapy comprises the combination of calcium phosphate compounds and two or more soluble fillers in the form of fibers, mesh or other materials which have the dual functions of reinforcing an in vivo implant while dissolving at a programmed rate to form macropores capable of receiving natural bone ingrowth.
    Type: Grant
    Filed: March 1, 2002
    Date of Patent: October 18, 2005
    Assignee: American Dental Association Foundation
    Inventors: Huakun Xu, Laurence C. Chow, Shozo Takagi, Frederick C. Eichmiller
  • Patent number: 6793725
    Abstract: A bone or dental implant material in the form of a paste includes a mixture of calcium phosphate powders, that are capable of forming hydroxyapatite, with liquid glycerol and hydroxypropyl methylcellulose and Na2HPO4. The paste will harden upon exposure to water with the time to harden controlled by the choice and ratio of constituents.
    Type: Grant
    Filed: January 23, 2002
    Date of Patent: September 21, 2004
    Assignee: ADA Foundation
    Inventors: Laurence C. Chow, Shozo Takagi
  • Publication number: 20030167093
    Abstract: A bone replacement material and therapy comprises the combination of calcium phosphate compounds and two or more soluble fillers in the form of fibers, mesh or other materials which have the dual functions of reinforcing an in vivo implant while dissolving at a programmed rate to form macropores capable of receiving natural bone ingrowth.
    Type: Application
    Filed: March 1, 2002
    Publication date: September 4, 2003
    Applicant: American Dental Association Health Foundation
    Inventors: Huakun Xu, Laurence C. Chow, Shozo Takagi, Frederick C. Eichmiller
  • Patent number: 6491900
    Abstract: Candies and confectioneries containing non-toxic sparingly soluble calcium and phosphate compounds as additives, cause the release of calcium and phosphate ions into the oral cavity gradually and persistently for a period no less than five minutes. Released calcium phosphate ions diffuse into partially demineralized tooth enamel or dentin, leasing to remineralization and repair of caries lesions, dental plaque, open dentinal tubules and exposed dentin. Agents and methods for remineralization of teeth, for reducing or eradicating cariogenic challenge in plaque following sucrose intake for producing effective anticaries actions without the use of fluoride and for desensitizing hypersensitive teeth are disclosed.
    Type: Grant
    Filed: January 26, 2001
    Date of Patent: December 10, 2002
    Assignee: American Dental Association Health Foundation
    Inventors: Laurence C. Chow, Shozo Takagi, Gerald L. Vogel
  • Publication number: 20020137812
    Abstract: A bone or dental implant material in the form of a paste includes a mixture of calcium phosphate powders, that are capable of forming hydroxyapatite, with liquid glycerol and hydroxypropyl methylcellulose and Na2HPO4. The paste will harden upon exposure to water with the time to harden controlled by the choice and ratio of constituents.
    Type: Application
    Filed: January 23, 2002
    Publication date: September 26, 2002
    Applicant: American Dental Association Health Foundation
    Inventors: Laurence C. Chow, Shozo Takagi
  • Patent number: 6325992
    Abstract: Calcium phosphate compositions that are particularly useful and unique as orthopedic and dental cements and remineralizers, as well as methods and kits for their use, and the resulting products are disclosed. The compositions comprise tetracalcium phosphate which has been prepared from a mixture with a calcium to phosphorous ratio of less than 2, or prepared and maintained under substantially anhydrous conditions prior to use or, preferably, both. The novel compositions are converted substantially to hydroxyapatite upon setting, are substantially gradually resorbable and replaced by bone when implanted in contact with living bony tissue, and offer distinct advantages in terms of cement strength, setting time and reliability and other properties.
    Type: Grant
    Filed: February 28, 2000
    Date of Patent: December 4, 2001
    Assignee: American Dental Association Health Foundation
    Inventors: Laurence C. Chow, Shozo Takagi
  • Publication number: 20010033831
    Abstract: Candies and confectioneries containing non-toxic sparingly soluble calcium and phosphate compounds as additives, cause the release of calcium and phosphate ions into the oral cavity gradually and persistently for a period no less than five minutes. Released calcium phosphate ions diffuse into partially demineralized tooth enamel or dentin, leasing to remineralization and repair of caries lesions, dental plaque, open dentinal tubules and exposed dentin. Agents and methods for remineralization of teeth, for reducing or eradicating cariogenic challenge in plaque following sucrose intake for producing effective anticaries actions without the use of fluoride and for desensitizing hypersensitive teeth are disclosed.
    Type: Application
    Filed: January 26, 2001
    Publication date: October 25, 2001
    Inventors: Laurence C. Chow, Shozo Takagi, Gerald L. Vogel