Filler for dental materials and dental materials containing the same

US4906446A · kind A · utility

Inventors

• Jurgen Engelbrecht · Seevetal, DE
• Michael Gunther · Hamburg, DE
• Helmut von Wallis · Henstedt-Ulzburg, DE

Key dates

• Filing date: Feb 29, 1988
• Grant date: Mar 6, 1990
• Expiry date: Feb 29, 2008

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2006/12
• WIPO field: Pharmaceuticals
• WIPO sector: Chemistry

Abstract

Silica gels of a mean grain size of about 0.5 to 50 .mu.m are subjected to a heat or acid treatment that considerably reduces their surface area and the volume of pores smaller than 50 nm, while maintaining approximately the same grain size distribution and amorphous structure. These products are colorless and can be worked into a resinous molding material in relatively large quantities, especially as a filler for dental materials based on polymerizable monomers, in particular mono-, di- or polyfunctional esters of acrylic or methacrylic acid. In the completely hardened condition, these materials have good mechanical characteristics, less polymerization shrinkage, very low thermal expansion coefficients, excellent transparency and tooth similarity resulting from the favorable refractive index of the filler, as well as very good ability to be polished and abrasion resistance.