# US 8,784,112 B2 · Tooth for dental arch model and method for producing the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,784,112 B2 - Document ID: US8784112B2 - Status: Granted - Kind: B2 - Application number: 14/046,178 - Filed: 2013-10-04 - Published: 2014-01-30 - Granted: 2014-07-22 - Earliest claimed: 2006-04-17 - Assignees: Shofu Inc. - Applicants: Kabushiki Kaisha Shofu - Inventors: Yusei Kadobayashi; Hirokazu Sato; Ryuichi Yoshimoto - Web page: https://patentgrep.com/patent/US8784112B2 ## CPC - G09B 23/283: {for dentistry or oral hygiene (G09B23/286 takes precedence)} - A61C 13/083: Porcelain or ceramic teeth {(A61C13/081 takes precedence; preparations A61K6/80)} - A61C 13/09: {Composite teeth, e.g. front and back section (A61C13/0835, A61C13/1023 take precedence)}; Multilayer teeth - G09B: EDUCATIONAL OR DEMONSTRATION APPLIANCES; APPLIANCES FOR TEACHING, OR COMMUNICATING WITH, THE BLIND, DEAF OR MUTE; MODELS; PLANETARIA; GLOBES; MAPS; DIAGRAMS (devices for psychotechnics or for testing reaction times A61B5/16; games, sports, amusements A63; projectors, projector screens G03B) - 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) ## Abstract The present invention relates to a tooth which is used in a dental arch model with which dental students can experience dental works in the oral cavity and practice treatments. More specifically, the present invention relates to a tooth composition for formation trainings such as abutment tooth formation and cavity preparation. Since conventionally used dental arch models have a grinding sensation different from a natural tooth, dental students having completed formation trainings such as abutment tooth formation and cavity preparation by using these conventional models are frequently puzzled to have different grinding and handling properties upon dental works in the oral cavity in practice. That is, these conventional dental arch models are largely different from a natural tooth in grinding sensation including slipperiness and easiness in grinding. A tooth for a dental arch model simulating the enamel texture and the dentin texture constituting a natural tooth whereby even the difference in grinding sensation between the enamel texture and the dentin texture constituting a natural tooth can be reproduced by forming at least the enamel portion with the use of a sintered body of an inorganic powder such as alumina. ## Claims ### Claim 1 A method for producing a tooth for a dental arch model comprising an enamel portion and a dentin portion, which is used for practice treatments, wherein the method comprises steps of: molding pellets including an inorganic powder and a binder to form a tooth molding having a two-layered structure of an enamel portion molding and a dentin portion molding, wherein the inorganic powder of the enamel portion molding has a primary particle diameter ranging from 0.1 μm to 1.0 μm and the inorganic powder of the dentin portion molding has a primary particle diameter ranging from greater than 1.0 μm to no more than 8.0 μm; heating the tooth molding at high treatment to degrease the binder; and sintering the degreased tooth molding at a predetermined temperature to form a sintered body of the tooth for a dental arch model comprising the enamel portion and the dentin portion. ### Claim 2 (depends on 1) The method according to claim 1, wherein the inorganic powder of the enamel portion molding and the inorganic powder of the dentin portion molding are each independently selected from the group consisting of alumina-based ceramic powder, zirconia-based ceramic powder, silica-based ceramic powder, titanium oxide-based ceramic powder, aluminum nitride ceramic powder and silicon nitride ceramic powder. ### Claim 3 (depends on 1) The method according to claim 1, wherein the inorganic powder of the enamel portion molding is alumina-based ceramic powder. ### Claim 4 (depends on 1) The method according to claim 1, wherein either or both of the enamel portion molding and the dentin portion molding further contain(s) a heavy metal element oxide selected from the group consisting of SrO, BaO, ZnO, ZnO2, and La2O3. ### Claim 5 (depends on 1) The method according to claim 1, wherein the sintered body of the inorganic powder constituting the enamel portion and the sintered body of the inorganic powder constituting the dentin portion each contain a void part, and the method further comprising a step of impregnating either or both of the void parts with a water-soluble material, a thermosoluble material or an organic material. ### Claim 6 (depends on 1) The method according to claim 1, wherein the dentin portion molding comprises a combustible tooth pulp mold, and wherein the dentin portion of the sintered body of the tooth comprises a tooth pulp portion, and the method further comprising a step of injecting a resin, a silicone rubber, a wax or a water-soluble material into the tooth pulp portion. ### Claim 7 (depends on 1) The method according to claim 1, wherein either or both of the enamel portion molding and the dentin portion molding is/are molded to have a false carious dental portion, and wherein either or both of the enamel portion of the sintered body of the tooth and the dentin portion of the sintered body of the tooth has/have the false carious dental portion. ### Claim 8 (depends on 7) The method according to claim 7, wherein each or both of the false carious dental portions in the enamel portion molding and in the dentin portion molding contain(s) at least any of a coloring material, fluorescent material and an X-ray contrast material. ### Claim 9 (depends on 8) The method according to claim 8, wherein the X-ray contrast material is a heavy metal element oxide selected from the group consisting of SrO, BaO, ZnO, ZnO2, and La2O3.