The present invention relates to compositions and uses for reducing the visibility of hypomineralised dental surfaces or subsurfaces, in particular in dental enamel. In one aspect, the invention involves a method of reducing visibility of a hypomineralised dental surface or subsurface, the method comprising (i) contacting the hypomineralised dental surface or subsurface with a liquid composition comprising at least 40% w/v of phosphopeptide (PP)-stabilized amorphous calcium phosphate (ACP) and/or amorphous calcium fluoride phosphate (ACFP) at a pH of less than or equal to pH 6; and (ii) subsequently to (i), raising the pH of the liquid composition applied to the hypomineralised dental surface or subsurface to equal to, or greater than, about 9, thereby forming a gel in and/or on the hypomineralised dental surface or subsurface, thereby reducing visibility of a hypomineralised dental surface or subsurface.

The invention relates to a process of manufacturing a dental milling block with a homogeneous color and/or translucency gradient. This process comprises the steps of providing a mold with a cavity having a z-direction and an x/y-direction, filling the cavity partially with a first powder up to a height H1, the first powder having a volume VP1 with a top and bottom surface, introducing a second powder on top of the first powder up to a height H2, the second powder having a volume VP2 with a top and bottom surface and, the top surface of the first powder being in contact with the bottom surface of the second powder and forming an intermediate region, providing a mixer unit with at least one rotatable mixing element, introducing the rotating mixing element in z-direction into the intermediate region, mixing the powder located in the intermediate region by rotating the mixing element, removing the rotating mixing element from the powder, compacting the powder, optionally applying heat to the compacted powder, the first powder differing from the second powder by its physical properties and/or chemical composition and/or color. The invention also relates to a process of producing a dental restoration using dental milling block obtainable according to this process.

The invention relates to the use of flowable, photopolymerizable composite resin compositions that comprise a nanoscale organic surface-modified filler for stereolithographically producing a shaped dental part and to a method for producing corresponding shaped dental parts. The method according to the invention is particularly simple, fast, reliable and cost-effective. It allows improved shaped dental parts to be produced, in particular improved bridges and crowns.

Polymeric shells which fit over one or more natural teeth to change the perceived color of the teeth, and optionally to provide orthodontic support. The shells can be prepared by thermoforming selected polymeric sheets which contain optical additives over a physical image of the teeth, or by depositing polymeric compositions containing optical additives over a physical image of the teeth, or by additive manufacturing based upon a digital image of the teeth. The optical additives cause the combination of the shell and the teeth to have a desired appearance. At least part of the shell preferably has transparency greater than 75%, particularly greater than 85%.

Polymeric shells which fit over one or more natural teeth to change the perceived color of the teeth, and optionally to provide orthodontic support. The shells can be prepared by thermoforming selected polymeric sheets which contain optical additives over a physical image of the teeth, or by depositing polymeric compositions containing optical additives over a physical image of the teeth, or by additive manufacturing based upon a digital image of the teeth. The optical additives cause the combination of the shell and the teeth to have a desired appearance. At least part of the shell preferably has transparency greater than 75%, particularly greater than 85%.

The present invention is directed to a process for producing a sintered lithium disilicate glass ceramic dental restoration out of a porous 3-dim article, the process comprising the step of sintering the porous 3-dim article having the shape of a dental restoration with an outer and inner surface to obtain a sintered lithium disilicate ceramic dental restoration, the sintered lithium disilicate glass ceramic dental restoration comprising Si oxide calculated as SiO2 from 55 to 80 wt.-%, Li oxide calculated as Li2O from 7 to 16 wt.-%, Al oxide calculated as Al2O3 from 1 to 5 wt.-%, and P oxide calculated as P2O5 from 1 to 5 wt.-%, wt.-% with respect to the weight of the dental restoration,
the sintering being done under reduced atmospheric pressure conditions, the reduced atmospheric pressure conditions being applied at a temperature above 600° C.

The present invention is also directed to a kit of parts comprising a porous 3-dim article having the shape of a dental milling block and a respective instruction of use.

The present invention is directed to a process for producing a sintered lithium disilicate glass ceramic dental restoration out of a porous 3-dim article, the process comprising the step of sintering the porous 3-dim article having the shape of a dental restoration with an outer and inner surface to obtain a sintered lithium disilicate ceramic dental restoration, the sintered lithium disilicate glass ceramic dental restoration comprising Si oxide calculated as SiO2 from 55 to 80 wt.-%, Li oxide calculated as Li2O from 7 to 16 wt.-%, Al oxide calculated as Al2O3 from 1 to 5 wt.-%, and P oxide calculated as P2O5 from 1 to 5 wt.-%, wt.-% with respect to the weight of the dental restoration,
the sintering being done under reduced atmospheric pressure conditions, the reduced atmospheric pressure conditions being applied at a temperature above 600° C.

The present invention is also directed to a kit of parts comprising a porous 3-dim article having the shape of a dental milling block and a respective instruction of use.

Dental compositions and methods of formulating a dental composition are described. In one embodiment, the dental composition comprises a polymerizable resin comprising one or more ethylenically unsaturated monomers or oligomers and nanoparticles. The nanoparticles have a refractive index of at least 1.600 and an average discrete or aggregate particle size of no greater than 100 nm. The dental composition further comprises inorganic metal oxide filler having a discrete or aggregate average particle size of at least 200 nm. The nanoparticles are present at a concentration to provide a refractive index differential between the cured polymerizable resin and inorganic metal oxide filler such that the contrast ratio of the dental composition is at least 40.

Dental compositions and methods of formulating a dental composition are described. In one embodiment, the dental composition comprises a polymerizable resin comprising one or more ethylenically unsaturated monomers or oligomers and nanoparticles. The nanoparticles have a refractive index of at least 1.600 and an average discrete or aggregate particle size of no greater than 100 nm. The dental composition further comprises inorganic metal oxide filler having a discrete or aggregate average particle size of at least 200 nm. The nanoparticles are present at a concentration to provide a refractive index differential between the cured polymerizable resin and inorganic metal oxide filler such that the contrast ratio of the dental composition is at least 40.

A pre-shaded ZrO.sub.2 block (e.g., a monochromatic block or polychromatic block) is sequentially infiltrated with a yttrium-containing solution at one porous surface and with water at a second porous surface to make a polychromatic/polytranslucent ZrO.sub.2 block.