Ceram.x Spectra™ ST is based on SphereTEC™ granulated filler technology. SphereTEC™ is the manufacturing process for well-defined, microscopic spherical superstructures composed of submicronic glass. The morphology of the fillers, the particle size distribution, and the microstructure of the surface are key to enhancing handling comfort and aesthetic results. Available in different viscosities: High Viscosity (HV) and Low Viscosity (LV).