Abstract: A dental system for cleaning a user's teeth and marginal gingiva with a drug solution includes a mouthpiece made for each user and having substantially the same shape as the teeth and the marginal gingiva of the user. The mouthpiece is designed to produce a gap between the mouthpiece and the teeth together with the marginal gingiva when placed to cover the teeth and the marginal gingiva of the user. The dental system also includes a drug solution supply unit and a drain unit, both connected to the mouthpiece, and a suction unit connected to the drain unit. The mouthpiece adheres to the marginal gingiva by a suction applied from the suction unit. The dental system cleans the teeth and the marginal gingiva with a stream of the drug solution flowing through the gap.

Abstract: A dental system for cleaning a user's teeth and marginal gingiva with a drug solution includes a mouthpiece made for each user and having substantially the same shape as the teeth and the marginal gingiva of the user. The mouthpiece is designed to produce a gap between the mouthpiece and the teeth together with the marginal gingiva when placed to cover the teeth and the marginal gingiva of the user. The dental system also includes a drug solution supply unit and a drain unit, both connected to the mouthpiece, and a suction unit connected to the drain unit. The mouthpiece adheres to the marginal gingiva by a suction applied from the suction unit. The dental system cleans the teeth and the marginal gingiva with a stream of the drug solution flowing through the gap.

Abstract: Powder of a metal serving as a precursor for ceramics (1) and a sintering additive are mixed with each other and heat-treated by microwave heating thereby nitriding or oxidizing the metallic powder from the surface thereof and diffusing the metal with a nitride or an oxide formed on the shell of the metal for obtaining porous ceramics (1) having homogeneous and fine closed pores (1a). The porous ceramics (1) according to the present invention, having the closed pores (1a) homogeneously diffusing at a high ratio, exhibits excellent characteristics when applied to an electronic circuit board or the like requiring moisture absorption resistance, low permittivity and low dielectric loss as well as mechanical strength.

Abstract: Powder of a metal serving as a precursor for ceramics (1) and a sintering additive are mixed with each other and heat-treated by microwave heating thereby nitriding or oxidizing the metallic powder from the surface thereof and diffusing the metal with a nitride or an oxide formed on the shell of the metal for obtaining porous ceramics (1) having homogeneous and fine closed pores (1a). The porous ceramics (1) according to the present invention, having the closed pores (1a) homogeneously diffusing at a high ratio, exhibits excellent characteristics when applied to an electronic circuit board or the like requiring moisture absorption resistance, low permittivity and low dielectric loss as well as mechanical strength.