Patents Represented by Attorney Ann M. Knab
  • Patent number: 7806694
    Abstract: Dental articles are produced using relatively low sintering temperatures to achieve high density dental articles exhibiting strengths equal to and greater than about 700 MPa. Ceramic powders comprised of nanoparticulate crystallites are used to manufacture dental articles. The ceramic powders may include sintering agents, binders and other similar additives to aid in the processing of the ceramic powder into a dental article. The ceramic powders may be processed into dental articles using various methods including, but not limited to, injection molding, gel-casting, slip casting, or electroforming, hand, cad/camming and other various rapid prototyping methods. The ceramic powder may be formed into a suspension, pellet, feedstock material or a pre-sintered blank prior to forming into the dental article.
    Type: Grant
    Filed: June 24, 2009
    Date of Patent: October 5, 2010
    Assignee: Pentron Ceramics, Inc.
    Inventors: Dmitri Brodkin, Moisey Y. Gamarnik
  • Patent number: 7331789
    Abstract: Dental posts and obturators are manufactured herein having a filling material applied to the apical end of the post and obturator such that the adherence strength between the filling material and the post or obturator is very high. The filling material is adhered to the post and obturator by applying one or more corona or plasma treatments to the surface of the post and obturator and thereafter applying the filling material to the surface-treated post and obturator. The surfaces of the post and obturator are modified by the corona or plasma treatments to create a highly adherent surface for the application of the filling material thereto. Dental restorations are manufactured herein wherein a veneer is applied to a dental substructure and the adherence strength of the veneer to the dental substructure is very high.
    Type: Grant
    Filed: February 6, 2004
    Date of Patent: February 19, 2008
    Assignee: Pentron Clinical Technologies, LLC
    Inventors: Ajit Karmaker, Arun Prasad
  • Patent number: 7275932
    Abstract: A two-part self-curing endodontic sealing system comprises a thiourea derivative, such as acetyl thiourea, and a hydroperoxide, such as cumene hydroperoxide. The thiourea derivative is used as a reducing agent and the hydroperoxide is used as an oxidizing agent.
    Type: Grant
    Filed: September 20, 2002
    Date of Patent: October 2, 2007
    Assignee: Pentron Clinical Technologies, LLC
    Inventors: Shuhua Jin, Weitao Jia
  • Patent number: 7275933
    Abstract: Method of manufacturing dental restorations using curable compositions including degradable macromonomers having one or more terminal acrylate or methacrylate functionality, a curing composition, a filler composition including bioactive particles of bioactive glass, bioactive glass-ceramics, calcium phosphates, calcium apatites, or mixtures thereof and optionally one or more polymerizable acrylate or methacrylate comonomers. Degradable macromonomers are manufactured from cyclic monomers with compounds having acrylate or methacrylate functionality. Depending on their use, the degradable macromonomer compositions further include one or more organic or inorganic fillers, including a calcium-based compound and/or a radiopacity-imparting agent. The compositions are particularly suitable for root canal sealants, implants, bone cements, and pulp capping materials.
    Type: Grant
    Filed: June 4, 2004
    Date of Patent: October 2, 2007
    Assignee: Pentron Clinical Technologies, LLC
    Inventors: Weitao Jia, Shuhua Jin
  • Patent number: 7252508
    Abstract: An endodontic obturator comprising a shaft section and a filler section fabricated of the same material and formed as a single unit. A handle section may be included and may be formed integrally with the shaft section and filler section as a single unit, or may be fabricated separately and attached to the single unit containing the shaft section and the filler section. An endodontic post is provided having a post section and a filler section fabricated of the same matrix material to provide a cohesive bond between the two sections.
    Type: Grant
    Filed: December 13, 2002
    Date of Patent: August 7, 2007
    Assignee: Pentron Clinical Technologies, LLC
    Inventors: Ajit Karmaker, Arun Prasad
  • Patent number: 7211136
    Abstract: A dental filling material comprising a thermoplastic polymer. The thermoplastic polymer may be biodegradable. A bioactive substance may also be included in the filling material. The thermoplastic polymer acts as a matrix for the bioactive substance. The composition may include other polymeric resins, fillers, plasticizers and other additives typically used in dental materials. The filling material is used for the filing of root canals.
    Type: Grant
    Filed: June 18, 2003
    Date of Patent: May 1, 2007
    Assignee: Pentron Clinical Technologies, LLC
    Inventors: Weitao Jia, Martin Trope, Bruce Alpert
  • Patent number: 7204875
    Abstract: An dental filling material comprising a thermoplastic polymer. The thermoplastic polymer may be biodegradable. A bioactive substance may also be included in the filling material. The thermoplastic polymer acts as a matrix for the bioactive substance. The composition may include other polymeric resins, fillers, plasticizers and other additives typically used in dental materials. The filling material is used for the filing of root canals.
    Type: Grant
    Filed: November 26, 2002
    Date of Patent: April 17, 2007
    Assignee: Pentron Clinical Technologies, LLC
    Inventors: Weitao Jia, Bruce Alpert
  • Patent number: 7204874
    Abstract: An endodontic filling material comprising a biodegrable thermoplastic polymer. A bioactive substance may also be included in the filling material. The thermoplastic polymer acts as a matrix for the bioactive substance. The composition may include other polymeric resins, fillers, plasticizers and other additives typically used in dental materials. The filling material is used for the filing of root canals.
    Type: Grant
    Filed: October 24, 2002
    Date of Patent: April 17, 2007
    Assignee: Pentron Clinical Technologies, LLC
    Inventors: Weitao Jia, Bruce Alpert
  • Patent number: 7186108
    Abstract: A curing apparatus wherein rapid curing is provided by using light, pressure, pressure and light, or purge, pressure and light to cure resinous materials by application of energy from an external source to excite polymerization in a polymerizable system. An air-tight chamber is provided to house the polymerizable dental material. The apparatus provides an automated system for curing the polymerizable material under light and pressure in the same unit. A purge cycle may be included to minimize or eliminate bubbles and provide an oxygen-free atmosphere.
    Type: Grant
    Filed: April 11, 2002
    Date of Patent: March 6, 2007
    Assignee: Pentron Laboratory Technologies, LLC
    Inventors: George Zychek, Daniel P. Clark
  • Patent number: 7168952
    Abstract: An endodontic post comprises a combined endodontic post and tip of filling material such as thermoplastic material in a single unit. Obuturating systems are provided by an endodontic carrier and attached filling material. The post and obturator include a protrusion or depression on the tip section of the device for better attachment of the filling material to the device. Alternatively the post and obuturator are fabricated of a tube having a tunnel extending therethrough into which filling material is injected. The filling material extends out of the apical section of the post and obturator to form a filler cone.
    Type: Grant
    Filed: August 1, 2003
    Date of Patent: January 30, 2007
    Assignees: Pentron Clinical Technologies, LLC
    Inventors: Ajit Karmaker, Larry A. Lopez, Bruce Alpert, Bruce A. Finnigan
  • Patent number: 7128573
    Abstract: A device for verifying the shade of a patient's teeth for the fabrication of a dental restorative comprising a mold section and a section for holding a shade tab, both of which are disposed on the shaft or rod of the device. A shade tab is formed in the mold section by applying composite material in the mold and curing it. The composite material is selected by the dentist based on the shade of the patient's teeth. After the composite material is cured, the resultant shade tab is removed from the mold and placed in the holder for the shade tab. This enables a dentist to effectively match the shade of a patient's teeth in order to provide a restoration that matches the patient's teeth.
    Type: Grant
    Filed: February 15, 2005
    Date of Patent: October 31, 2006
    Assignee: Pentron Clinical Technologies, LLC
    Inventors: Cornelis H. Pameijer, Weitao Jia
  • Patent number: 7086864
    Abstract: An endodontic post comprising a combined endodontic post and filling material tip in a single unit. To use the post unit, the device is placed in an oven or heater to heat and soften the thermoplastic material. The device will then be placed in a root canal that has been opened to a predetermined dimension by use of endodontic files, to seal the apical end. If necessary, the gutta percha can be compacted toward the apex, while it is still in the softened state, to ensure the apex is adequately sealed. The post is then cemented into place by lining the canal walls with a bonding agent and filling the interface between the post and the walls of the canal with a dual cure resin cement. This will result in a coronal seal of the canal via resin restorative material and an apical seal of the canal by means of gutta percha and sealant. The remaining portion of the post, extending supra-gingivally, will be used to build a core around it. Any excess will be cut off.
    Type: Grant
    Filed: June 6, 2002
    Date of Patent: August 8, 2006
    Assignees: Pentron Clinical Technologies, LLC
    Inventors: Larry A. Lopez, Bruce A. Finnigan, Ajit Karmaker, Bruce Alpert, Weitao Jia
  • Patent number: 6994549
    Abstract: Solid free form fabrication techniques such as fused deposition modeling and three-dimensional printing are used to create a dental restoration. Three-dimensional printing comprises inkjet printing a binder into selected areas of sequentially deposited layers of powder. Each layer is created by spreading a thin layer of powder over the surface of a powder bed. Instructions for each layer may be derived directly from a CAD representation of the restoration. The area to be printed is obtained by computing the area of intersection between the desired plane and the CAD representation of the object. All the layers required for an aesthetically sound restoration can be deposited concurrently slice after slice and sintered/cured simultaneously. The amount of green body oversize is equivalent to the amount of shrinkage which occurs during sintering or curing.
    Type: Grant
    Filed: October 5, 2001
    Date of Patent: February 7, 2006
    Assignee: Jeneric/Pentron Incorporated
    Inventors: Dmitri Brodkin, Carlino Panzera, Paul Panzera
  • Patent number: 6846181
    Abstract: Ready-to-use preshaped, prefabricated cured structural components are prepared in a variety of shapes and sizes to be used in the fabrication of dental appliances. Preferably the structural components are fabricated of a fiber-reinforced composite material or a particulate-filled composite material comprising fibers or particulate filler impregnated with a polymeric matrix. The polymeric matrix is partially or fully cured to the point of sufficient hardness to provide a ready-to-use structural component for use in the fabrication of dental appliances such as orthodontic retainers, bridges, space maintainers, tooth replacement appliances, splints, crowns, partial crowns, dentures, posts, teeth, jackets, inlays, onlays, facings, veneers, facets, implants, abutments, cylinders, and connectors.
    Type: Grant
    Filed: October 26, 2001
    Date of Patent: January 25, 2005
    Assignee: Pentron Corporation
    Inventors: Ajit Karmaker, Martin L. Schulman, Arun Prasad
  • Patent number: 6843967
    Abstract: A curing apparatus providing rapid curing by using light, pressure, pressure and light, or purge, pressure and light to cure resinous materials by application of energy from an external source to excite polymerization in a polymerizable system. A curing chamber is provided to house the polymerizable dental material. The apparatus utilizes light emitting diodes (LEDs) to radiate energy to polymerize the dental materials. The LEDs are positioned optimally within the curing apparatus to provide efficient, effective polymerization of the dental materials.
    Type: Grant
    Filed: April 10, 2003
    Date of Patent: January 18, 2005
    Assignee: Pentron Laboratory Technologies, LLC
    Inventor: Daniel P. Clark
  • Patent number: 6827576
    Abstract: A dental post comprising a rod fabricated of fiber-reinforced composite material. The rod comprises a plurality of frustoconical sections arranged coaxially along the longitudinal axis of the rod. Preferably the rod has consistent width along the longitudinal axis wherein the frustoconical sections each have the same tapered width and same length. The number of frustoconical units per rod can vary. The frustoconical sections may vary in shape. Moreover, the rod may include a channel therein extending along the longitudinal axis thereof. The rod may also include one or more grooves extending along the surface thereof.
    Type: Grant
    Filed: June 26, 2002
    Date of Patent: December 7, 2004
    Assignee: Pentron Laboratory Technologies, LLC
    Inventors: Ajit Karmaker, Arun Prasad
  • Patent number: 6821462
    Abstract: Solid free form fabrication techniques such as fused deposition modeling and three-dimensional printing are used to create a shell used in the manufacture of a dental restoration. Three-dimensional printing includes ink-jet printing a binder into selected areas of sequentially deposited layers of powder. Each layer is created by spreading a thin layer of powder over the surface of a powder bed. Instructions for each layer may be derived directly from a CAD representation of the restoration. The area to be printed is obtained by computing the area of intersection between the desired plane and the CAD representation of the object. All the layers required for an aesthetically sound shell can be deposited concurrently slice after slice and sintered/cured simultaneously.
    Type: Grant
    Filed: September 5, 2001
    Date of Patent: November 23, 2004
    Assignee: Jeneric/Pentron, Inc.
    Inventors: Martin L. Schulman, Carlino Panzera
  • Patent number: 6808659
    Abstract: Solid free form fabrication techniques such as fused deposition modeling and three-dimensional printing are used to create a shell or die used in the manufacture of a dental restoration. Three-dimensional printing includes ink-jet printing a binder into selected areas of sequentially deposited layers of powder. Each layer is created by spreading a thin layer of powder over the surface of a powder bed. Instructions for each layer may be derived directly from a CAD representation of the restoration. The area to be printed is obtained by computing the area of intersection between the desired plane and the CAD representation of the object. All the layers required for an aesthetically sound shell can be deposited concurrently slice after slice and sintered/cured simultaneously.
    Type: Grant
    Filed: October 22, 2001
    Date of Patent: October 26, 2004
    Assignee: Jeneric/Pentron Incorporated
    Inventors: Martin L. Schulman, Carlino Panzera
  • Patent number: 6802894
    Abstract: This invention is directed to lithium disilicate (Li2Si2O5) based glass-ceramics comprising silica, lithium oxide, alumina, potassium oxide and phosphorus pentoxide. The glass-ceramics are useful in the fabrication of single and multi-unit dental restorations (e.g. anterior bridges) made by heat pressing into refractory investment molds produced using lost wax techniques. The glass-ceramics have good pressability, i.e., the ability to be formed into dental articles by heat-pressing using commercially available equipment. In accordance with one embodiment directed to the process of making the glass-ceramics, the compositions herein are melted at about 1200 ° to about 1600 ° C., thereafter cast into steel molds in the shape of cylindrical blanks (pellets), or alternately, cooled to the crystallization temperature. The resulting glass blank are heat-treated to form glass-ceramic blanks via a one or two step heat-treatment cycle preferably in the temperature range of about 400 ° to about 1100 ° C.
    Type: Grant
    Filed: June 25, 2002
    Date of Patent: October 12, 2004
    Assignee: Jeneric/Pentron Incorporated
    Inventors: Dmitri Brodkin, Carlino Panzera, Paul Panzera
  • Patent number: 6787584
    Abstract: Curable compositions comprising degradable macromonomers having one or more terminal acrylate or methacrylate functionality, a curing composition, a filler composition comprising bioactive particles of bioactive glass, bioactive glass-ceramics, calcium phosphates, calcium apatites, or mixtures thereof and optionally one or more polymerizable acrylate or methacrylate comonomers. Degradable macromonomers are manufactured from cyclic monomers with compounds having acrylate or methacrylate functionality. Depending on their use, the degradable macromonomer compositions further comprise one or more organic or inorganic fillers, including a calcium-based compound and/or a radiopacity-imparting agent. The compositions are particularly suitable for root canal sealants, implants, bone cements, and pulp capping materials.
    Type: Grant
    Filed: December 5, 2001
    Date of Patent: September 7, 2004
    Assignee: Pentron Corporation
    Inventors: Weitao Jia, Shuhua Jin