Abstract: 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 %, P2O5 25 to 85 wt %, Al2O3 5 to 25 wt % and Li2O 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.

Abstract: 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 %, P2O5 25 to 85 wt %, Al2O3 5 to 25 wt % and Li2O 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.

Abstract: 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.

Abstract: Calcium phosphate glass-ceramics of high strength and toughness is disclosed. These materials are excellent for artificial dental or bone materials. The strength and toughness of these materials are improved substantially in comparison with conventionally used calcium phosphate glass-ceramics by adding rare earth oxide in them. For dental materials, good aesthetic appearance to natural teeth is also obtained by adding one type, or two or more types of compounds selected from oxides of iron, manganese, cerium, titanium, nickel, zinc, cobalt, tungsten, chromium, and vanadium as color component. Also, if necessary, Al.sub.2 O.sub.3 and/or SiO.sub.2 is contained as coloring assistant agent in that composite. Moreover it is possible to adjust the color tone of each individual's teeth. The rare earth oxide, coloring component, and coloring assistant agent added are incorporated in crystals of calcium phosphate. Consequently, they cause no elution during use.

Abstract: Dental materials using calcium phosphate glass-ceramics and having the color tone with high approximation to that of natural teeth. In those dental materials, calcium phosphate composite, nickel oxide and one or more other type of compounds selected from oxides of iron, manganese, cerium, titanium and tungsten, are contained as coloring component. Also, if necessary, Al.sub.2 O.sub.3 and/or SiO.sub.2 is contained as a color assisting agent in that composite. The calcium phosphate glass-ceramic according to this invention consists of the same components as that of natural teeth. Besides, it is possible to adjust the color tone delicately to match with the color tone of each individual`s teeth. Moreover, the coloring components are incorporated in crystals of calcium phosphate. Consequently, they cause no elution during use and are therefore ideal as dental material.