A rotary mill for grinding recycled glass materials into particles has a housing defining an impact chamber with a rotor in the chamber at the bottom of an inclined guide wall underneath the feed opening. The rotor has a plurality of axially extending, angularly spaced massive impact hammers so that the impact hammers impact and deflect the solid materials onto a plurality of shatter bars located at the peripheral wall. Each of the impact hammers has a leading blade element of a hardened steel which has a front face inclined relative to a bottom portion of the guide surface so that an outer edge of the front face is angularly advanced relative to an inner edge thereof.

One aspect relates to a process for the preparation of a quartz glass grain, including providing a silicon dioxide granulate from a pyrogenically produced silicon dioxide powder, making a glass melt out of silicon dioxide granulate, making a quartz glass body out of at least part of the glass melt and reducing the size of the quartz glass body to obtain the quartz glass grain. One aspect further relates to a quartz glass grain which is obtainable by this process. One aspect further relates to opaque quartz glass bodies, which are obtainable by further processing of the quartz glass grain.

One aspect relates to a process for the preparation of a quartz glass grain, including providing a silicon dioxide granulate from a pyrogenically produced silicon dioxide powder, making a glass melt out of silicon dioxide granulate, making a quartz glass body out of at least part of the glass melt and reducing the size of the quartz glass body to obtain the quartz glass grain. One aspect further relates to a quartz glass grain which is obtainable by this process. One aspect further relates to opaque quartz glass bodies, which are obtainable by further processing of the quartz glass grain.

A dental material comprising a pigment, wherein the pigment contains Al, Cr and one or more of Y, La and lanthanides. The dental material allows mimicking the red coloration of natural teeth and natural oral mucosa. Also provided is the use of the dental material and the pigment and starting compositions for making the pigment in the preparation of a dental restoration. Furthermore, a process for preparing a dental restoration and a process for preparing the pigment is provided.

A dental material comprising a pigment, wherein the pigment contains Al, Cr and one or more of Y, La and lanthanides. The dental material allows mimicking the red coloration of natural teeth and natural oral mucosa. Also provided is the use of the dental material and the pigment and starting compositions for making the pigment in the preparation of a dental restoration. Furthermore, a process for preparing a dental restoration and a process for preparing the pigment is provided.

Masking compositions useful for dental restoration, particularly masking compositions used as a coating to mask the unnatural color of milled lithium-silicate glass-ceramic dental restorations in soft states before crystallization cycle, and method of making same. Some embodiments relate to masking compositions comprising at least one glaze powder, at least one opacifier, and at least one colorant. Some embodiments relate to coating, drying, cooling, characterizing, and firing of dental restorations.

Masking compositions useful for dental restoration, particularly masking compositions used as a coating to mask the unnatural color of milled lithium-silicate glass-ceramic dental restorations in soft states before crystallization cycle, and method of making same. Some embodiments relate to masking compositions comprising at least one glaze powder, at least one opacifier, and at least one colorant. Some embodiments relate to coating, drying, cooling, characterizing, and firing of dental restorations.

The invention relates to a glazing composition for a porous dental zirconia article, the glazing composition comprising liquid, glass particles, fluorescing component(s) comprising europium, optionally hydrophilic silica nano-particles, and optionally hydrophobic silica nano-particles, wherein the fluorescing component(s) can be contained in the glass particles or as separate component. The invention also relates to a process for sintering a porous dental zirconia article with a glazing composition on its surface.

The invention relates to a glazing composition for a porous dental zirconia article, the glazing composition comprising liquid, glass particles, fluorescing component(s) comprising europium, optionally hydrophilic silica nano-particles, and optionally hydrophobic silica nano-particles, wherein the fluorescing component(s) can be contained in the glass particles or as separate component. The invention also relates to a process for sintering a porous dental zirconia article with a glazing composition on its surface.

The present invention describes a hybrid device (1) for a recirculation shower, allowing purification and either recycling of water or discarding of water, wherein said hybrid device (1) comprises a recirculation loop (2), a filter system (4) with a nano-filter (5) such as for instance an electropositive nano-ceramic filter, e.g. a nano alumina (fiber) filter, at least one filter quality sensor (3), at least one pre-filter (6), and wherein the hybrid device (1) is arranged to redirect the water from recirculation to drainage when the at least one filter quality sensor (3) indicates the need thereof.