1. A powdery filler for dental materials containing particles of feldspar or its derivatives with an average diameter (d50) of 0.5 to 5 μm, the particles being coated with a silicon compound containing reactive groups, the dental materials being composites. 2 . The powder filler according to claim 1, wherein the reactive groups contain polymerizable groups. The powder filler according to claim 2, wherein the polymerizable groups contain epoxy groups or vinyl groups, preferably methacrylic or acrylic groups. The powder filler according to claim 1, wherein the feldspar is selected from the group of sodium-lime or alkaline feldspars. The powder filler according to claim 1, wherein the feldspar is selected from perthite, albite, oligoclase, andesine, labradorite, bitovnite, anorthite and SiO depleted feldspar derivatives such as nepheline and mixtures thereof. The powder filler according to claim 1, 4 or 5, wherein the feldspar particles have an average diameter (d50) of from 0.5 to 3.5 μm, preferably from 0.8 to 1.5 μm. The powder filler according to claim 1, 4 or 5, wherein the feldspar has light transmission. The powder filler according to claim 1, wherein the filler is characterized by a bimodal particle diameter distribution. The powdered filler of claim 8, where one maximum of the bimodal distribution is in the range from 0.5 to 1 μm, the other maximum is in the range from 1 to 3.5 μm. A method of obtaining a powdered filler according to any one of paragraphs. 1-9, containing the following steps: - grinding feldspar, - silanization of particles with reactive silicon soy1. Порошкообразный наполнитель для стоматологических материалов, содержащий частицы полевого шпата или его производных при их среднем диаметре (d50) от 0,5 до 5 мкм при этом частицы имеют покрытие из кремниевого соединения, содержащего реакционноспособные группы, причем стоматологические материалы представляют собой композиты.2. Порошкообразный наполнитель по п.1, где реакционноспособные группы соде
