Abstract: An injector comprises a cylindrical barrel, a movable body housed in the barrel, and a plunger coming into separable contact with the movable body. The movable body includes a main body having an outer diameter smaller than an inner diameter of the barrel, a disk-shaped seal body disposed on the main body and including an outer circumferential end brought into close contact with an inner circumferential surface of the barrel, and at least one projecting portion projecting from the main body toward the inner circumferential surface of the barrel. A distance from a central axis of the movable body to a leading end of the at least one projecting portion is smaller than a half of an outer diameter of the seal body.

Abstract: An injector comprises a cylindrical barrel including a discharge port, a seal body coming into close contact with an inner circumferential surface of the barrel, a plunger for pushing and moving the seal body to the discharge port side of the barrel, and a stopper disposed on one of the barrel and the plunger and coming into elastic contact with the other in a radial direction of the barrel.

Abstract: An injector comprises a cylindrical barrel including a discharge port, a seal body coming into close contact with an inner circumferential surface of the barrel, a plunger for pushing and moving the seal body to the discharge port side of the barrel, and a stopper disposed on one of the barrel and the plunger and coming into elastic contact with the other in a radial direction of the barrel.

Abstract: An injector comprises a cylindrical barrel, a movable body housed in the barrel, and a plunger coming into separable contact with the movable body. The movable body includes a main body having an outer diameter smaller than an inner diameter of the barrel, a disk-shaped seal body disposed on the main body and including an outer circumferential end brought into close contact with an inner circumferential surface of the barrel, and at least one projecting portion projecting from the main body toward the inner circumferential surface of the barrel. A distance from a central axis of the movable body to a leading end of the at least one projecting portion is smaller than a half of an outer diameter of the seal body.

Abstract: The present invention relates to a curable composition in which polymer and monomer which is neither soluble nor swellable (able to swell) in the polymer are mixed homogeneously. More particularly, the present invention relates to a curable composition, in which polymer and urethane metha(acrylate) which is neither soluble nor swellable in the polymer are mixed homogeneously. The present invention also relates to a cured composition of the curable composition.

Abstract: The present invention provides a dental curable material suitable for a production of an artificial teeth having a strong toughness, wear resistance, transparency and moldability, which comprises a silane-treated silica uniformely dispersed in urethane (meth)acrylate (a): said silica has a 1 to 85 nm, with at least one silane compound represented by the formula (1):YnSiX.sub.4-n (1)wherein Y is a hydrocarbon group or a reactive group containing a vinyl-polymerizable group; X is a hydrolyzable group; and n is an integer of 1, 2 or 3, and is uniformly dispersed in a urethane (meth)acrylte (b).