Abstract: A method of forming a dental restoration for a tooth having an outer surface includes acquiring a first three-dimensional representation representative of the outer surface of the tooth; generating a design of a first part of the dental restoration based on the first three-dimensional representation of the tooth; forming the first part of the dental restoration; preparing the tooth to form a prepared tooth while forming the first part of the dental restoration; obtaining a second three-dimensional representation of the prepared tooth; generating a design of a second part of the dental restoration based on at least the second three-dimensional representation of the prepared tooth; merging the design of the second part of the dental restoration to the first part of the dental restoration; and forming the second part of the dental restoration.

Abstract: The present disclosure provides methods including obtaining an insert comprising a sieve defining openings each having a diameter of 10 to 200 micrometers; placing a volume of a fluid containing a photopolymerizable composition and a contaminant in the insert; and subjecting the volume of the fluid to a centrifugal force to separate the contaminant from at least a portion of the photopolymerizable composition by retaining the contaminant in the insert and passing at least a portion the photopolymerizable composition through the sieve of the insert to provide a separated photopolymerizable composition. Systems are also provided, including an additive manufacturing apparatus, a centrifuge, and an insert configured to be inserted into the centrifuge. The methods and systems can advantageously assist in reclaiming photopolymerizable composition that has been contaminated, for reuse.

Abstract: A system having at least one dental blank and an associated shade guide. The dental blank exhibits a non-uniform color shading, and the shade guide comprises a plurality of shade specimens each exhibiting a particular color shading representing the same color shading present in a partial area within the dental blank. A method of making a dental restoration includes the use of the system. The invention facilitates making a dental restoration having a color shading resembling the color shading of a natural tooth.

Abstract: A method of making a physical object by additive manufacturing. The method has the steps of providing a light hardenable primary material (11), building up the object (100) by successively hardening portions of the light hardenable primary material (11) by irradiating the portions with light, coating at least a part of the object (100) with a light permeable coating or oxygen protective material; and irradiating the coated object (100) with light and thereby post-hardening any light hardenable material (11).

Abstract: The invention relates to A curable composition for producing dental composite crowns, the composition comprising a resin matrix comprising polymerizable (meth)acrylate(s) not comprising a urethane moiety, polymerizable urethane(meth)acrylate(s), wherein the polymerizable (meth)acrylate(s) not comprising an urethane moiety are used in excess over the polymerizable urethane(meth)acrylate(s), a filler matrix comprising nanocluster(s), fumed silica in an amount below 8 wt. % with respect to the weight of the whole composition, an initiator system comprising photoinitiator(s), organic dye(s), the curable composition not comprising softener in an amount of more than 5 wt. % with respect to the weight of the whole composition, the curable composition having a viscosity below 150 Pa*s at 23° C. and a shear rate of 1 s?1. The invention also relates to a cured article obtained by radiation curing this curable composition by use of an additive-manufacturing method.

Abstract: The invention relates to a 3D printing system comprising a 3D printing device for manufacturing at least two workpieces. The invention also relates to a method for manufacturing at least two workpieces by means of the 3D printing system. Furthermore, the invention relates to an adapter set for attaching workpiece holders to a 3D printing device.

Abstract: A 3D printing system (10) for manufacturing at least one physical object comprises at least one reservoir (12) for receiving hardenable material; at least one light engine (22) configured to irradiate light onto a focal plane within the reservoir of the hardenable material to form a layer of hardened material; at least one build platform (18) for carrying the physical object to be manufactured; and a controller configured to select at least one or at least two optical resolutions from two or more optical resolutions available in the 3D printing system for irradiating the hardenable material based on a predetermined surface quality of the physical object to be manufactured.

Abstract: A system (1) for washing a 3D-printed object (4). The system (1) has a washing device (2) and a workpiece (3) that includes the 3D-printed object (4). The washing device (2) has a container (7) that forms a process chamber (8) for receiving a liquid cleaning agent (9), and the container (7) has an inlet (10) into the process chamber (8). The workpiece (3) further has a support structure (6) that supports the 3D-printed object (4) and a base (5) supporting the support structure (6). The base (5), in a mating relationship with the inlet (10), forms a restraint preventing the workpiece (3) from passing through the inlet (10) in a situation in which the workpiece (3) is placed with the 3D-printed object (4) located within the process chamber (8).

Abstract: The invention relates to A curable composition for producing dental composite crowns, the composition comprising a resin matrix comprising polymerizable (meth)acrylate(s) not comprising a urethane moiety, polymerizable urethane(meth)acrylate(s), wherein the polymerizable (meth)acrylate(s) not comprising an urethane moiety are used in excess over the polymerizable urethane(meth)acrylate(s), a filler matrix comprising nanocluster(s), fumed silica in an amount below 8 wt. % with respect to the weight of the whole composition, an initiator system comprising photoinitiator(s), organic dye(s), the curable composition not comprising softener in an amount of more than 5 wt. % with respect to the weight of the whole composition, the curable composition having a viscosity below 150 Pa*s at 23° C. and a shear rate of 1 s?1. The invention also relates to a cured article obtained by radiation curing this curable composition by use of an additive-manufacturing method.

Abstract: A method of forming a vitreous bond abrasive article is presented that includes receiving, by a manufacturing device having one or more processors, a digital object comprising data specifying a plurality of layers of a vitreous bond abrasive article precursor. The vitreous bond abrasive article precursor includes abrasive particles bonded together by a vitreous bond precursor material and an organic compound. The vitreous bond abrasive article precursor further comprises at least one of: at least one tortuous cooling channel extending at least partially through the vitreous bond abrasive article precursor or at least one arcuate cooling channel extending at least partially through the vitreous bond abrasive article precursor. The method also includes generating, with the manufacturing device by an additive manufacturing process, the vitreous bond abrasive article precursor based on the digital object.

Abstract: The invention relates to a radiation curable composition for additive-manufacturing processes, the composition comprising (meth)acrylate component(s) not comprising an urethane moiety having a molecular weight Mw of at least 1,000 as Component A1, photo initiator as Component B, red, yellow or orange dye or combination thereof as Component C, blue dye having a light absorption band in the range of 350 to 420 nm as Component D, and optionally stabilizer as Component E. The invention further relates to a process of producing an elastomeric 3-dim article from the radiation curable composition in an additive-manufacturing process and the obtained elastomeric 3-dim article.

Abstract: The invention relates to a coloured curable composition for use in an additive manufacturing process, the composition comprising a curable resin composition comprising radiation curable components, a photo initiator, a dye composition comprising a dye D1 and a dye D2, dye D1 having a light absorption maximum within a wave length range from 400 to 530 nm, dye D2 showing a light absorption maximum within a wave length range from 540 to 650 nm. The invention also relates to a 3-dim composite article obtained by processing the curable composition in an additive manufacturing process.

Abstract: An additive manufacturing system has a light permeable base, a build carrier for holding a workpiece and a light source which is arranged to emit light through the light permeable base. The light permeable base and the build carrier are positionable relative to each other in a build dimension in which the workpiece is built up. The system further has a resin vat in which the light permeable base forms a wall portion thereof. The system further comprises a plurality of resin supplies for supplying different light hardenable resins in direct contact with each other in said vat. The system facilitates the rapid manufacturing of a dental restoration having a color gradation.

Abstract: A method of layerwise building up an object from at least a first and a second light hardenable resin on a 3D printing device, and a 3D printing device that is configured to perform such a method. The 3D printing device has a build platform on which the object can be built up, a light-transmissive carrier comprising a plurality of recesses and a light projector for projecting a light-pattern through the carrier.

Abstract: The invention relates to a preformed dental composite crown being characterized by its shape and chemical composition, the shape being characterized as follows: having an occlusal top surface and depending buccal, mesial, distal and lingual side surfaces, the side surfaces being connected to each other and forming a crown cervix, the wall thickness of the crown at the crown cervix being lower than 0.6 mm; at least two of opposing depending side surfaces having a concave shape; the chemical composition of the material the preformed dental composite crown is made of being a hardened composition comprising the following components: nano-filler(s) in an amount from 20 to 70 wt. %, resin matrix in an amount from 20 to 75 wt. %, wt. % with respect to the weight of the chemical composition, the resin matrix comprising urethane(meth)acrylate(s) and (meth)acrylate(s) not comprising a urethane moiety.

Abstract: A method of making a physical object by additive manufacturing. In the method a hardenable primary material is provided, the object is built up by successively hardening layers of the hardenable primary material, and the object is cleaned from excess material by moving the object and thereby generating a mass inertial force in the excess material. The invention facilitates the making of objects by additive manufacturing.

Abstract: The present disclosure provides a build platform for use in an additive manufacturing device that is builds up an object from layers of a light-hardenable resin, wherein the build platform comprises a build surface for building up the object thereon, and wherein the build surface comprises a ceramic material. The disclosure also provides a method of making a build surface comprises a ceramic surface. Further, the disclosure provides additive manufacturing devices that include build platforms comprising ceramic material. The disclosure also describes articles made using the methods and devices described.

Abstract: A device for progressively building up an object from a light hardenable material. The device has a perforated build platform for the object. The build platform forms a build surface that faces a light source. The build platform and the light source are positionable relative to each other by computer control. The device is further configured for supplying the light hardenable material through the perforation of the build platform for building up the object. The invention enables the making of colored objects by stereolithography.

Abstract: The invention relates to the use of a printing sol as construction material in an additive manufacturing process for producing a 3-dim article, the printing sol comprising solvent(s), nano-sized crystalline zirconia particles in an amount from 2 to 25 vol.-% with respect to the volume of the sol, the average primary particle size of the nano-sized crystalline zirconia particles being in a range up to 50 nm, a first monomer being a polymerizable surface modification agent represented by formula A-B, with A being capable of attaching to the surface of the nano-sized crystalline zirconia particles and B being a radiation curable group, optionally a second monomer, the second monomer comprising at least one radiation curable moiety but no acidic or silane group(s), photo initiator(s). The invention also relates to a ceramic article obtainable according to such a process.

Abstract: A device (1) for spinning a 3D printed workpiece (100). The device has a rotor (2) for spinning about a spinning axis (A) and a receptacle (8) for holding the workpiece (100). The receptacle (8) is pivotally attached to the rotor (2) for swiveling about a swivel axis (B) that is transverse to the spinning axis (A). The pivotal attachment enables swiveling of the receptacle (8) between a first angular orientation relative to the spinning axis (A) and a different second angular orientation relative to the spinning axis (A). The device (1) further has a balancing weight (9) that is movably arranged relative to the receptacle (8). The balancing weight (9) is lockable at different distances relative to the receptacle (8).