Provided is a dental bulk block made from a glass-ceramic material having a crystalline phase embedded in an amorphous glass matrix. The crystalline phase includes eucryptite and at least one lithium silicate-based crystalline phase selected from the group consisting of lithium metasilicate and lithium disilicate. The dental bulk block is a functionally graded material having a crystalline size gradient with respect to a depth thereof and having no interface at a point of change in main crystalline size gradient value. The bulk block that is heat-treated at 820° C. for 40 minutes exhibits a characteristic peak of a spodumene crystalline phase in an X-ray diffraction analysis result graph unlike the bulk block that is heat-treated at 820° C. for 2 minutes.

The invention relates to a radiation-curable radiopaque dental composition comprising a resin matrix comprising cross-linkable component(s) as Component A, ethylenically unsaturated component(s) with acidic moiety as Component B, an initiator system comprising photoinitiator(s) as Component C, reducing agent(s) as Component D, Component A containing at least two (meth)acrylate moieties and a brominated aromatic moiety selected from brominated resorcinol, catechol, tyrosol, benzoic acid, or phenol moieties. The composition can be used for producing an x-ray visible dental adhesive composition, restoration primer or dental sealant.

A method of manufacturing a dental restoration including a construction step (S2) of preparing construction data for a dental tool machine for machining the dental restoration from a workpiece. The construction data defines at least the geometry of the dental restoration within the workpiece. The method includes a starting step (S3) of starting machining of the dental restoration from the workpiece in accordance with the construction data. The method also includes a preparing step (S4) of starting preparing, before termination of the construction step (S2), the dental tool machine at least through equipping it with all the consumables essential for starting the starting step (S3), and completing preparing the dental tool machine before start of the starting step (S3).

Disclosed herein are methods of manufacturing an oral appliance, the method comprising the steps of: a) importing into a computer aided design (CAD) computer program a digitized data set obtained from a three-dimensional scan of a patient's dentition; b) preparing a three-dimensional electronic model of the patient's dentition; c) subtracting the three-dimensional electronic model of the patient's dentition from an image of a solid block to obtain an appliance data set; and d) manufacturing a dental appliance in accordance with the appliance data set. Also disclosed are devices made by the above method, and methods of treating a condition, for example a sleep breathing disorder, by using a device made by the above method.

A zirconia sintered body for dental use may not require coloring or firing after shaping, and have aesthetic properties. A preform may include a body and a stem. The body has a Vickers hardness of 4 to 20 HV (GPa), and is machinable. The stem has a width of 4 mm or less at a position where it protrudes from a central portion of the body. At this position, the central portion has a cross-sectional geometric shape with an inscribed circle having a diameter of >12 mm, and a circumscribed circle having a diameter of <20 mm. The body shows a color change from an upper to a lower end portion of the body, and unchanging patterns of increase and decrease of the L*a*b* color system values from the upper to the lower end portion. The preform can be shaped into a dental restoration such as a crown.

The present invention relates to a method for manufacturing a prefabricated crown by processing and tabulating the type, size, material and color of prefabricated crowns for sub-gingival and supra-gingival, and actual and try-in crowns by a table system (1), and a prefabricated crown manufactured therefrom, and the method includes a first step (S100) of classifying a plurality of prefabricated crowns by type and size by a first module (5) of the table system (1); a second step (S110) of classifying the plurality of prefabricated crowns by color and material by a second module (7) of the table system (1); a third step (S120) of tabulating the type, size, color and material data of the prefabricated crowns classified in the first and second steps (S100, S110) by a third module (9) of the table system (1), and assigning an identification code to each data; a fourth step (S130) of manufacturing the tabulated plurality of prefabricated crowns; and a fifth step (S140) of inputting the measured type, size, color and material data of patient's tooth into a fourth module (11) of the table system (1) to select a prefabricated crown corresponding thereto.

A holding device (100) for a blank (200), having a first holding element (101-1) for inserting the blank (200); and a second holding element (101-2) for clamping the blank (200), which is lockable to the first holding element (101-1) by a rotational movement.

A zirconia sintered body is provided and includes yttria and zirconia, containing yttria by a content ranging from 4.5 mol % or more to 6.5 mol % or less and zirconia as the remainder, the total light transmittance of a 1-mm thick sample measured in compliance with JIS K 7361-1 being 46.5% or higher, the three-point bending strength being 700 MPa or higher, and a ratio of an integrated value for the total light transmittance to an integrated value for the parallel light transmittance of a 1-mm thick sample measured at the measurement wavelength ranging from 400 to 700 nm being 1.3% or less.

A method of machining at least one dental restoration (1) from a workpiece (2) using one or more dental took (3), including a step of defining, a target contour (4) of the dental restoration (1); also including a step of predicting the deflection of the dental tool (3) during pre-machining through a model based on one or more machining parameters; a step of determining based on the prediction step one or more primary locations (5) at which the target contour (4) would have been damaged during pre-machining; a step of modifying the target contour (4) or the corresponding machining path by adding an oversize of material (6) substantially only at the primary locations (5) for preventing damage; and a step of pre-machining the workpiece (2) based on the modified target contour (17) or the corresponding modified machining path.

A computer-implemented method of planning of the shapes of free-form tool paths (P) for simultaneous two-sided machining of a dental restoration (1) having an individual free-form target geometry from a workpiece (2) by using a dental tool machine (3) having at least two tool spindles each having at least one tool (4) arranged on a different side of the workpiece (2) which is simultaneously movable along an axis (y) relative to the tools (4) thereby imposing a kinematic axis coupling. The method includes a step of determining transformations (T′, T″) of the target geometry by which the kinematic axis coupling is converted into a common coupling parameter for both tools (4); and a step of generating dependent on these transformations (T′, T″) the shapes of the free-form tool paths (P) in which the common coupling parameter is identical in time for all participating tool spindles that are driven simultaneously.