Abstract: An antimicrobial, water-insoluble silicate glass powder is provided. The starting glass includes 30 to 70 weight percent SiO2, 0 to 1 weight percent Na2O, 0 to 1 weight percent K2O, 0 to 40 weight percent MgO, 0 to 40 weight percent CaO, 0 to 40 weight percent SrO, 0 to 40 weight percent BaO, 0 to 25 weight percent Al2O3, 0 to 20 weight percent P2O5, 0 to 20 weight percent B2O3, wherein the sum of the alkali oxide contents is less than 1.5 weight percent in the total composition of the starting glass. The starting glass also includes, as biocidally active components, ions or atoms of the elements Ag, Zn, Cu, Ce, Te, or I with total proportions of greater than 2.5 weight percent.

Abstract: The invention relates to a glass ceramic, wherein the initial glass comprises 30-65 percent (by weight) SiO2; 5-30 percent (by weight) Na2O; 5-30 percent (by weight) CaO, and 0-15 percent (by weight) P2O5, and wherein the main crystalline phases comprise alkali-alkaline earth-silicate and/or alkali silicate and/or alkaline earth silicate. The invention is characterized in that either a glass ceramic with a single crystalline phase 1 Na2O-2 CaO-3 SiO2 is excluded, or the crystalline size of the glass ceramic is <10 ?m, or the weight fraction of SiO2 is <47%.