# US 12,594,151 B2 · Processing CT scan of dental impression > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,594,151 B2 - Document ID: US12594151B2 - Status: Granted - Kind: B2 - Application number: 18/649,448 - Filed: 2024-04-29 - Published: 2024-08-22 - Granted: 2026-04-07 - Earliest claimed: 2019-06-25 - Assignees: James R. Glidewell Dental Ceramics, Inc. - Applicants: James R. Glidewell Dental Ceramics, Inc. - Inventors: Sergey Nikolskiy; Fedor Chelnokov - Web page: https://patentgrep.com/patent/US12594151B2 ## CPC - A61C 9/0053: {Optical means or methods, e.g. scanning the teeth by a laser or light beam} - A61B 6/032: {Transmission computed tomography [CT]} - A61B 6/466: {adapted to display 3D data} - A61B 6/5217: {extracting a diagnostic or physiological parameter from medical diagnostic data} - A61C 9/0006: {Impression trays} - A61C 9/0046: {Data acquisition means or methods} - A61C 13/0004: {Computer-assisted sizing or machining of dental prostheses} - G06T 17/20: Finite element generation, e.g. wire-frame surface description, {tesselation} - A61B 6/51: for dentistry - G06T 2210/56: Particle system, point based geometry or rendering - A61C: DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE (non-driven toothbrushes A46B; {tongue scrapers A61B17/24;} preparations for dentistry A61K6/00; preparations for cleaning the teeth or mouth A61K8/00, A61Q11/00) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL ## Abstract A computer-implemented method and system of determining a material surface from a volumetric density file includes generating a density frequency distribution of a volumetric density file of a dental impression and determining an iso-value of density between air and a particular material in the density frequency distribution. A computer-implemented method and system of creating a digital model from a CT scan of a physical dental impression includes selecting an iso-value of density for a digital volumetric density file having one or more voxels, generating one or more digital surface points in virtual 3D space for each of one or more voxels, and selecting a subset of digital surface points from the one or more digital surface points. A computer-implemented method and system of optimizing a digital surface includes moving one or more digital surface points to satisfy a criteria of optimum digital surface selection. ## Claims ### Claim 1 A computer-implemented method of determining a material surface from a volumetric density file, comprising: receiving a volumetric density file of a CT scanned dental impression; selecting an iso-value of density for the volumetric density file to provide one or more voxels; generating one or more digital surface points in a 3D point cloud for each of one or more voxels; selecting a subset of digital surface points from the one or more digital surface points to provide a reduced 3D point cloud; selecting a criteria of digital surface optimization on the subset of digital surface points; moving one or more digital surface points to satisfy the criteria of optimum digital surface selection; and generating a digital surface mesh for the reduced 3D point cloud. ### Claim 2 (depends on 1) The method of claim 1, further comprising generating a density frequency distribution of the volumetric density file. ### Claim 3 (depends on 2) The method of claim 2, wherein generating the density frequency distribution further comprises detecting contaminants in the dental impression. ### Claim 4 (depends on 1) The method of claim 1, wherein the criteria of optimum digital surface selection comprises a maximum of density derivative along a normal of each digital surface point of the digital surface points. ### Claim 5 (depends on 1) The method of claim 1, wherein moving the one or more digital surface points comprises moving one or more digital surface points to the maximum of density derivative. ### Claim 6 A digital impression processing system for creating a digital model from a CT scan of a physical dental impression, comprising: a processor; a computer-readable storage medium comprising instructions executable by the processor to perform steps comprising: receiving a volumetric density file of a CT scanned dental impression; selecting an iso-value of density for the volumetric density file to provide one or more voxels; generating one or more digital surface points in a 3D point cloud for each of one or more voxels; selecting a subset of digital surface points from the one or more digital surface points to provide a reduced 3D point cloud; selecting a criteria of digital surface optimization on the subset of digital surface points; moving one or more digital surface points to satisfy the criteria of optimum digital surface selection; and generating a digital surface mesh for the reduced 3D point cloud. ### Claim 7 (depends on 6) The system of claim 6, further comprising generating a density frequency distribution of the volumetric density file. ### Claim 8 (depends on 7) The system of claim 7, wherein generating the density frequency distribution further comprises detecting contaminants in the dental impression. ### Claim 9 (depends on 6) The system of claim 6, wherein the criteria of optimum digital surface selection comprises a maximum of density derivative along a normal of each digital surface point of the digital surface points. ### Claim 10 (depends on 6) The system of claim 6, wherein moving the one or more digital surface points comprises moving one or more digital surface points to the maximum of density derivative. ### Claim 11 A non-transitory computer readable medium storing executable computer program instructions for creating a digital model from a CT scan of a physical dental impression, the computer program instructions comprising instructions for: receiving a volumetric density file of a CT scanned dental impression; selecting an iso-value of density for the volumetric density file to provide one or more voxels; generating one or more digital surface points in a 3D point cloud for each of one or more voxels; selecting a subset of digital surface points from the one or more digital surface points to provide a reduced 3D point cloud; selecting a criteria of digital surface optimization on the subset of digital surface points; moving one or more digital surface points to satisfy the criteria of optimum digital surface selection; and generating a digital surface mesh for the reduced 3D point cloud. ### Claim 12 (depends on 11) The medium of claim 11, further comprising generating a density frequency distribution of the volumetric density file. ### Claim 13 (depends on 12) The medium of claim 12, wherein generating the density frequency distribution further comprises detecting contaminants in the dental impression. ### Claim 14 (depends on 11) The medium of claim 11, wherein the criteria of optimum digital surface selection comprises a maximum of density derivative along a normal of each digital surface point of the digital surface points. ### Claim 15 (depends on 11) The medium of claim 11, wherein moving the one or more digital surface points comprises moving one or more digital surface points to the maximum of density derivative.