Patents Represented by Attorney Ann M. Knab
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Patent number: 7806694Abstract: 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: GrantFiled: June 24, 2009Date of Patent: October 5, 2010Assignee: Pentron Ceramics, Inc.Inventors: Dmitri Brodkin, Moisey Y. Gamarnik
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Patent number: 7331789Abstract: 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: GrantFiled: February 6, 2004Date of Patent: February 19, 2008Assignee: Pentron Clinical Technologies, LLCInventors: Ajit Karmaker, Arun Prasad
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Patent number: 7275932Abstract: 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: GrantFiled: September 20, 2002Date of Patent: October 2, 2007Assignee: Pentron Clinical Technologies, LLCInventors: Shuhua Jin, Weitao Jia
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Patent number: 7275933Abstract: 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: GrantFiled: June 4, 2004Date of Patent: October 2, 2007Assignee: Pentron Clinical Technologies, LLCInventors: Weitao Jia, Shuhua Jin
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Patent number: 7252508Abstract: 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: GrantFiled: December 13, 2002Date of Patent: August 7, 2007Assignee: Pentron Clinical Technologies, LLCInventors: Ajit Karmaker, Arun Prasad
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Patent number: 7211136Abstract: 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: GrantFiled: June 18, 2003Date of Patent: May 1, 2007Assignee: Pentron Clinical Technologies, LLCInventors: Weitao Jia, Martin Trope, Bruce Alpert
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Patent number: 7204875Abstract: 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: GrantFiled: November 26, 2002Date of Patent: April 17, 2007Assignee: Pentron Clinical Technologies, LLCInventors: Weitao Jia, Bruce Alpert
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Patent number: 7204874Abstract: 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: GrantFiled: October 24, 2002Date of Patent: April 17, 2007Assignee: Pentron Clinical Technologies, LLCInventors: Weitao Jia, Bruce Alpert
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Patent number: 7186108Abstract: 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: GrantFiled: April 11, 2002Date of Patent: March 6, 2007Assignee: Pentron Laboratory Technologies, LLCInventors: George Zychek, Daniel P. Clark
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Patent number: 7168952Abstract: 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: GrantFiled: August 1, 2003Date of Patent: January 30, 2007Assignees: Pentron Clinical Technologies, LLCInventors: Ajit Karmaker, Larry A. Lopez, Bruce Alpert, Bruce A. Finnigan
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Patent number: 7128573Abstract: 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: GrantFiled: February 15, 2005Date of Patent: October 31, 2006Assignee: Pentron Clinical Technologies, LLCInventors: Cornelis H. Pameijer, Weitao Jia
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Patent number: 7086864Abstract: 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: GrantFiled: June 6, 2002Date of Patent: August 8, 2006Assignees: Pentron Clinical Technologies, LLCInventors: Larry A. Lopez, Bruce A. Finnigan, Ajit Karmaker, Bruce Alpert, Weitao Jia
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Patent number: 6994549Abstract: 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: GrantFiled: October 5, 2001Date of Patent: February 7, 2006Assignee: Jeneric/Pentron IncorporatedInventors: Dmitri Brodkin, Carlino Panzera, Paul Panzera
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Patent number: 6846181Abstract: 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: GrantFiled: October 26, 2001Date of Patent: January 25, 2005Assignee: Pentron CorporationInventors: Ajit Karmaker, Martin L. Schulman, Arun Prasad
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Patent number: 6843967Abstract: 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: GrantFiled: April 10, 2003Date of Patent: January 18, 2005Assignee: Pentron Laboratory Technologies, LLCInventor: Daniel P. Clark
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Patent number: 6827576Abstract: 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: GrantFiled: June 26, 2002Date of Patent: December 7, 2004Assignee: Pentron Laboratory Technologies, LLCInventors: Ajit Karmaker, Arun Prasad
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Patent number: 6821462Abstract: 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: GrantFiled: September 5, 2001Date of Patent: November 23, 2004Assignee: Jeneric/Pentron, Inc.Inventors: Martin L. Schulman, Carlino Panzera
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Patent number: 6808659Abstract: 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: GrantFiled: October 22, 2001Date of Patent: October 26, 2004Assignee: Jeneric/Pentron IncorporatedInventors: Martin L. Schulman, Carlino Panzera
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Patent number: 6802894Abstract: 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: GrantFiled: June 25, 2002Date of Patent: October 12, 2004Assignee: Jeneric/Pentron IncorporatedInventors: Dmitri Brodkin, Carlino Panzera, Paul Panzera
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Patent number: 6787584Abstract: 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: GrantFiled: December 5, 2001Date of Patent: September 7, 2004Assignee: Pentron CorporationInventors: Weitao Jia, Shuhua Jin