Abstract: This specification discloses optical light-weight glass having a composition of SiO.sub.2 47--70, Li.sub.2 O 5.5-21, K.sub.2 O 2-30, Na.sub.2 O 0-30 (Li.sub.2 O+Na.sub.2 O+K.sub.2 O 21-50), TiO.sub.2 9.5-24, B.sub.2 O.sub.3 0-20, CaO 0-20, MgO+SrO+BaO+ZnO 0-4, Al.sub.2 O.sub.3 0-5 and ZrO.sub.2 +La.sub.2 O.sub.3 +Ta.sub.2 O.sub.5 +WO.sub.3 0-3, all being in % by weight, and having a refractive index (n.sub.d) of 1.58-1.65, an Abbe number (.gamma..sub.d) of 35-50 and a specific gravity of 2.69 or less. This optical glass is light in weight, high in transparency and low in dispersion, and is particularly suitable for spectacle lenses, but can also be utilized for photographic lenses.

Abstract: A dental implant and a method of making same are disclosed. The dental implant comprises a biocompatible metal core and a multi-layer bioglass coating applied on the core. The outer layer of the multi-layer coating is formed of a bioglass whose chemical composition is selected from within the range of composition particularly defined by the present invention and which has substantially the same thermal expansion coefficient as the core. The inner layer is formed of a bioglass whose chemical composition is substantially the same as the glass of the outer layer with the exception that the content of TiO.sub.2 is increased within a particularly determined range.

Abstract: A biologically active glass and class-ceramic composition useful for making surgical and dental implants comprising, by mol %,:______________________________________ SiO.sub.2 35.about.60 B.sub.2 O.sub.3 5.about.15 Na.sub.2 O 10.about. 30 CaO 5.about. 40 TiO.sub.2 0.5.about. 10 P.sub.2 O.sub.5 0.about. 15 K.sub.2 O 0.about. 20 Li.sub.2 O 0.about. 10 MgO 0.about. 5 Al.sub.2 O.sub.3 + ZrO.sub.2 + Nb.sub.2 O.sub.5 0.about. 8 La.sub.2 O.sub.3 + Ta.sub.2 O.sub.5 + Y.sub.2 O.sub.3 0.about.8 and F.sub.2 0.about.15.

Abstract: This specification discloses fluophosphate optical glass of low dispersion containing no beryllium and arsenic and having an optical constant nd=1.43-1.48 and .nu.d=85-97 and which can be produced stably and easily.

Abstract: Dental implant is composed of a core and a coating layer of a biologically active glass or glass-ceramic material covering at least a part of the core to be embedded in the jawbone. The glass or glass-ceramic layer comprises at least two separated portions spaced from each other.

Abstract: A dental implant is disclosed which comprises a dental root part to be embedded in a jaw bone alone or in combination with a dental crown part or a dental crown support part. At least a major portion of the surface of the dental root part to be in contact with the jaw bone is formed of a biologically active material. The contour of the surface of the dental root part is rotationally symmetrical with its diameter being constant or decreased monotonously from its one end, that is, the collum dentis portion to the other end, that is, the root end portion. The root end portion is smoothly closed.

Abstract: An optical glass composition having high refractive index and low dispersion is disclosed which is characterized in that it contains no harmful thorium compound and instead contains WO.sub.3 in a content of 10 to 35 percent by weight introduced into the system of B.sub.2 O.sub.3 -La.sub.2 O.sub.3 -ZrO.sub.2 -Ta.sub.2 O.sub.5. The optical glass herein disclosed has a high refractive index (nd) ranging from 1.85 to 1.97 and a low Abbe's number (.nu.d) ranging from 28 to 38. Also, the optical glass is stable against devitrification and excellent in chemical durability.

Abstract: An optical glass having a high dispersion and a refractive index in the range of from 1.53 to 1.86 and an Abbe number in the range of from 21 to 43 comprises substantially the following components in percent by weight:P.sub.2 O.sub.5 : 10-72R.sup.I.sub.2 O: 0-41ZnO: 0-46(provided that R.sup.I.sub.2 O + ZnO: 5-50)Nb.sub.2 O.sub.5 : 22-63wherein R.sup.I.sub.2 O is Li.sub.2 O, Na.sub.2 O or K.sub.2 O or combination of two or more thereof.

Abstract: A glass for eyeglass lenses has a refractive index between 1.68 and 1.71, Abbe number between 41.6 and 46.5 and specific gravity between 2.88 and 3.14 and consists essentially of B.sub.2 O.sub.3, CaO and at least one of TiO.sub.2 and Nb.sub.2 O.sub.5, the CaO being included in substantial amount.

Abstract: Optical glass contains 11 to 32% by weight of P.sub.2 O.sub.5, 34 to 60% by weight of PbO and 22 to 50% by weight of Nb.sub.2 O.sub.5.

Abstract: A high refractive, low dispersive optical glass composition based on a B.sub.2 O.sub.3 -La.sub.2 O.sub.3 -Y.sub.2 O.sub.3 -TiO.sub.2 quaternary system which is free of thorium oxide. The glass made of the composition has a refractive index of 1.79 to 1.93 and an Abbe number of 30 to 41.

Abstract: In thorium-free optical glass containing oxygen ions and fluorine ions as anions, cations in the glass calculated as oxides are in the following ranges of percentage by weight:______________________________________ B.sub.2 O.sub.3 10-44, La.sub.2 O.sub.3 30-66, Y.sub.2 O.sub.3 4-31, ZrO.sub.2 0-11, Ta.sub.2 O.sub.5 0-21, Gd.sub.2 O.sub.3 0-12, Nb.sub.2 O.sub.5 0-19, RO 0- 9, PbO 0-10, TiO.sub.2 0- 8, and GeO.sub.2 0-26, ______________________________________where RO is an ingredient or a combination of two or more ingredients of MgO, CaO, SrO, BaO and ZnO, and part of the oxygen ions is substituted for 0.2 to 10% by weight of fluorine ions relative to the glass. The thorium-free optical glass has a refractive index of 1.71 to 1.85 and Abbe number of 40 to 57.

Abstract: A composition for optical glass having a refractive index from 1.57 to 1.98 and Abbe number from 18 to 46 comprises, by weight, 1 to 25% B.sub.2 O.sub.3, 20 to 50% P.sub.2 O.sub.5 and 22 to 70% Nb.sub.2 O.sub.5.

Abstract: An optical glass having a refractive index (nd) in the range of 1.71 to 1.74 and Abbe number (v) in the range of from 49 to 54, the glass consisting essentially of, by weight, 1 to 5% SiO.sub.2, 30 to 41% B.sub.2 O.sub.3, 2 to 6% Al.sub.2 O.sub.3, 42 to 50% La.sub.2 O.sub.3, 3 to 7% ZrO.sub.2, and 1 to 12% Ta.sub.2 O.sub.5.

Abstract: A glass body having a fluorescent pattern inwardly of a surface thereof is formed by depositing a first material in a predetermined pattern on a surface of glass containing readily ion-exchangeable first ions, the first material containing second ions capable of ion-exchange with the first ions, one of the glass and the first material containing ions for providing a fluorescence center, and by causing the second ions to penetrate into the glass through ion-exchange with the first ions so that the fluorescence-center providing ions may be distributed in a pattern which is in positive or negative relationship with the predetermined pattern.

Abstract: A glass body having a fluorescent pattern inwardly of a surface thereof is formed by depositing a first material in a predetermined pattern on a surface of glass containing readily ion-exchangeable first ions, the first material containing second ions capable of ion-exchange with the first ions, one of the glass and the first material containing ions for providing a fluorescence center, and by causing the second ions to penetrate into the glass through ion-exchange with the first ions so that the fluorescence-center providing ions may be distributed in a pattern which is in positive or negative relationship with the predetermined pattern.