Use of agglomerates of silicic acid as fillers in dental materials

US4389497A · kind A · utility

Assignee

• ESPE Fabrik Pharmazeutischer Praparate GmbH · DE

Inventors

• Werner Schmitt · Starnberg, DE
• Robert Purrmann · Starnberg, DE
• Peter Jochum · Meiningen, AT
• Heinz-Joachim Hubner · Herrsching am Ammersee, DE

Key dates

• Filing date: Jul 22, 1981
• Grant date: Jun 21, 1983
• Expiry date: Jul 22, 2001

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2004/50
• WIPO field: Pharmaceuticals
• WIPO sector: Chemistry

Abstract

The invention relates to the use of agglomerates of silicic acid having an average agglomerate size of 0.5 to 50 .mu.m, containing primary particles of silicic acid having an average particle size of 1 to 100 nm and serving as filler in dental materials on the basis of ethylenically unsaturated polymerizable monomers. This reinforcing filler is practically colorless and can be blended in considerable quantity into the polymerizable monomer material especially mono-functional and di-functional as well as polyfunctional esters of the acrylic acid and the methacrylic acid and yields a satisfactorily processable plastically deformable paste. If necessary, the agglomerated silicic acid is used together with non-agglomerated micro-fine silicic acid of an average particle size of 1 to 100 nm. The shaped bodies obtained after the curing of the polymerizable material with the fillers show superior compressive strength, low thermal expansion, high colour stability and low water absorption, and moreover can be finished to high luster. The agglomerated fillers provided according to the invention are generally suitable for tooth filling preparations and tooth restoration materials as well as fo…