Nova Patents
EP1514850A1

Translucent and radio-opaque glass ceramics

Abstract

Radio-opaque glass ceramics are described which have high chemical durability and adjustable translucency, brightness and coefficient of thermal expansion.

EP1514850A1, drawing sheet 1
Sheet 1 of 14

Term

Term ended

Projected expiry passed 30 August 2024, 2.1 years ago.

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40 claims: 4 independent, 36 dependent

  1. 1
    Translucent and radio-opaque glass ceramic which comprises Component Wt.% SiO 2 46.0 - 58.0 P 2 O 5 2.0 - 6.0 Me 2 O 3 10.0 - 22.0 Me 2 O 14.5 - 30.0 MeO 4.0 - 13.0 F 0.3 - 3.0, with Me 2 O 3 being selected from Component Wt.% Al 2 O 3 8.0 - 16.0 Y 2 O 3 0.1 - 9.0 B 2 O 3 0 - 9.0, Me 2 O being selected from Component Wt.% Li 2 O 0 - 3.0 Na 2 O 0 - 9.0 K 2 O 3.0 - 14.0 Rb 2 O 0 - 12.5 Cs 2 O 0 - 18.0, MeO being selected from Component Wt.% MgO 0 - 9.0 CaO 0 - 2.5 SrO 0 - 13.0 with the proviso that at least one of SrO or MgO ≥ 3.1 wt.% if CaO is 0,1 to 2.5 wt.-%, and which has apatite as a main crystalline phase.
  2. 10
    Glass ceramic according to any one of claims. 1 to. 9 which contains one or more additional crystal phases.
  3. 27
    A method to preparing a dental layering material comprising mixing of a translucent and radio-opaque glass ceramic ac-. cording to any one of claims 1 to 21 with one or more glasses or glass ceramics selected from the group consisting of SiO 2 -Al 2 O 3 -K 2 O based glasses and glass ceramics (with cubic or tetragonal leucite crystals), SiO 2 -B 2 O 3 -Na 2 O based glasses and glass ceramics, alkali-silicate based glasses and glass ceramics, alkali-zinc-silicate silico-phosphate and/or SiO 2 -ZrO 2 based glasses and glass ceramics.
  4. 32
    Method according to claims 30 or 31, wherein the dental restoration is an inlay, an onlay, a bridge, an abutment, a facing, a veneer, a facet, a crown, a partial crown , a framework or a coping.
Independent claims4