täyteainesosat

Täyteainesosat (filler components) are the individual constituents that make up the filler phase of composite materials, most notably in dental composites but also in other polymer systems. They are inorganic particles embedded in a polymer or resin matrix and serve to reinforce the material, improve wear resistance, and influence physical properties such as stiffness, strength, and thermal expansion. In dental materials, the filler also contributes to radiopacity, aiding radiographic detection.

The typical constituents of täyteaineisiin include inorganic filler particles, such as silica, glass (including barium- or strontium-containing glasses for radiopacity), and sometimes ceramic oxides like zirconia. Fillers vary in size and shape; common categories are macrofillers (large particles), microfillers, and nanofillers, with hybrids combining different sizes to balance properties. The filler content is usually high, often around 60–85 percent by weight, which markedly affects modulus, strength, wear resistance, and polymerization shrinkage of the final composite.

To bond effectively with the surrounding resin matrix, filler surfaces are commonly treated with coupling agents, most notably silanes. Silanization creates a chemical bridge between the inorganic filler and the organic resin, improving interfacial adhesion, load transfer, and long-term stability.

Manufacturing of täyteaineosat typically involves milling or precipitating the filler material, followed by surface treatment before mixing with the resin. The choice of filler type, size distribution, and surface treatment determines the performance of the final composite in terms of mechanical properties, wear, esthetics, and handling.