Tomy Incorporated

Kyushu Refractories Co., Ltd.

Makoto Mitsudo

Seiji Kihara

Akira Watanabe

Masaaki Orikasa

Yoshimitsu Takeuchi

Mitsuhiro Matsushima

An orthodontic appliance comprising a main body for orthodontic treatment and a bonding base connected to the main body and capable of adhering to the teeth, wherein the main body and the bonding base each comprise calcium phosphate crystallizing glass. The calcium phosphate crystallizing glass preferably comprises CaO 10 to 60 wt %, P O 25 to 85 wt %, Al O 5 to 25 wt % and Li O 0.01 to 5 wt %, and has Vickers hardness Hv based on JIS Z2244 of 4.5 GPa or lower, and bending strength based on JIS R1601 of 100 MPa or higher.

Orthodontic appliance

Glass ceramics used as dental material, artifical bone, etc. which contain 0.01 to 25 parts by weight of alkali metal oxides (R.sub.2 O), such as Li.sub.2 O, Na.sub.2 O, K.sub.2 O, Rb.sub.2 O, and Cs.sub.2 O, in 100 parts by weight of CaO-Al.sub.2 O.sub.3 -P.sub.2 O.sub.5 system material. During the casting for obtaining the glass ceramics, the molten fluid is sufficiently distributed to the fine corners of a mold, and the temperature for crystallization is low. Also, the time required for the crystallization is short and the crystalline formed shows no internal defects, and has high bending strength.

Glass ceramics

Growing community of inventors

Akaiwa-gun, Japan

Makoto Mitsudo