A dental retraction and impression system providing self-retracting and impression taking of a prepared tooth in one step. Paired setting materials simultaneously retract gingiva, widen a sulcus around the tooth, and take an impression of the tooth and margins. A low viscosity setting gingival retracting impression material having an astringent and a high viscosity setting impression material set together. The high viscosity setting impression material is heavy body and has a higher viscosity than the low viscosity setting gingival retracting material so as to force the low viscosity setting gingival retracting impression material into the gingival space or sulcus.

An embodiment according to the present invention provides a dental gypsum powder including a hemihydrate gypsum and a water-reducing agent, wherein the mass ratio of the water-reducing agent to the hemihydrate gypsum is 0.1 to 1%, the content of particles having a particle diameter of 10 μm or less is 15 to 35 volume %, the content of particles having a particle diameter of 20 μm or less is 40 to 55 volume %, and the content of particles having a particle diameter of 30 μm or less is 55 to 75 volume %.

An embodiment according to the present invention provides a dental gypsum powder including a hemihydrate gypsum and a water-reducing agent, wherein the mass ratio of the water-reducing agent to the hemihydrate gypsum is 0.1 to 1%, the content of particles having a particle diameter of 10 μm or less is 15 to 35 volume %, the content of particles having a particle diameter of 20 μm or less is 40 to 55 volume %, and the content of particles having a particle diameter of 30 μm or less is 55 to 75 volume %.

A light-curable dental impression material comprising (a) a polymerizable polysiloxane resin composition comprising compounds of formula (I)
E−(L.sup.1−Z).sub.n−L.sup.2−E   (I)
(b) a particulate filler; and
(c) a photoinitiator.

A light-curable dental impression material comprising (a) a polymerizable polysiloxane resin composition comprising compounds of formula (I)
E−(L.sup.1−Z).sub.n−L.sup.2−E   (I)
(b) a particulate filler; and
(c) a photoinitiator.

A light-curable dental impression material comprising (a) a polymerizable polysiloxane resin composition comprising compounds of formula (I)
E−(L.sup.1−Z).sub.n−L.sup.2−E   (I)
(b) a particulate filler; and
(c) a photoinitiator.

A monomer composition, including: an acidic phosphoric acid ester (A); an amine-based catalyst (B); and a (meth)acrylate (E) having at least one of a urethane bond or a —NHC(═S)O— bond.

A monomer composition, including: an acidic phosphoric acid ester (A); an amine-based catalyst (B); and a (meth)acrylate (E) having at least one of a urethane bond or a —NHC(═S)O— bond.

A device for enhancing the appearance of a person's lips is formed from a curved member configured to fit between the person's upper or lower lip and an adjacent gum at the front of the mouth. The curved member has a gingival portion configured to be placed on the person's gums, a top surface and an extension connected to the top surface and extending from a longitudinal edge of the top surface to overlap and extend beyond the gingival portion. The extension is configured to rest against and evert the person's upper or lower lip when the device is placed between the lip and the person's gum.

A device for enhancing the appearance of a person's lips is formed from a curved member configured to fit between the person's upper or lower lip and an adjacent gum at the front of the mouth. The curved member has a gingival portion configured to be placed on the person's gums, a top surface and an extension connected to the top surface and extending from a longitudinal edge of the top surface to overlap and extend beyond the gingival portion. The extension is configured to rest against and evert the person's upper or lower lip when the device is placed between the lip and the person's gum.