Glass ceramic as filler in polymerizable dental filling compositions

US3973972A · kind A · utility

Assignee

• Jenaer Glaswerk, Schott & Gen. · DE

Inventor

• Gerd Muller · Jena, DE

Key dates

• Filing date: Sep 11, 1974
• Grant date: Aug 10, 1976
• Expiry date: Sep 11, 1994

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C03C10/0027
• WIPO field: Pharmaceuticals
• WIPO sector: Chemistry

Abstract

Transparent, colorless, particulate glass ceramic having a low coefficient of expansion, a high absorptivity for X-rays and which is useful in dental filling compositions, has the following ingredients, expressed as percent by weight of oxides: SiO.sub.2 40-55%, Al.sub.2 O.sub.3 15-25%, Li.sub.2 O 3-5%, P.sub.2 O.sub.5 3-10%, MgO 0-3%, ZnO 0-5%, ZrO.sub.2 2-7%, Ta.sub.2 O.sub.5 0-7% and La.sub.2 O.sub.3 >12-20%.