SphereTECTM – Granulated Spherical Filler Technology

Abstract Body: Generally, high filler load supports mechanical strength and reduces polymeriza-tion shrinkage of a composite. Maximum filler loads can be achieved by combining particles of different size categories: large particles form a pre-packed grid and smaller ones can occupy the space in between. This approach is widely used in dental composites and, depending on the size of combined filler particles, different types of hybrid composites are produced. More specifically, large fillers >1μm facilitate high filler loads due to their lower surface area and corresponding lower energy to wet the particles with resin. Yet, at the same time, they impair esthetical prop-erties like a materials’ gloss by being torn out under mechanical strain, leaving significant surface defects. On the other hand, smaller, i.e. sub-micron particles are favorable to obtain superior esthetics and generally better wear resistance, but are more difficult to wet, limiting the work-ability of a composite. To overcome the described technical conflict, the new generation of ceram.x® is equipped with SphereTEC™, the latest development in the field of composite filler technology. SphereTEC™ granulated composite fillers comprise glass particles of sub-micron size only. The average particle size of SphereTEC™ fillers is about 15 μm. When combined with iso-lated sub-micron particles, SphereTEC™ fillers allow the maximization of sub-micron glass filler load in a composite. Due to their specific morphology, SphereTEC™ fillers contribute to unique features of the new ceram.x. Most notably, they reduce the intrinsic friction of ceram.x® when under shear stress, facilitating excellent composite adaptation to cavity surfaces. Due to its distinct microstructure, SphereTEC™ fillers also reduce the amount of resin needed in a composite and thus minimize the stickiness to metal instruments. Upon polishing SphereTEC™ embedded sub-micron fillers are removed layer-by-layer providing a smooth surface. In vitro polishing data shows that SphereTEC™ fillers facilitate high gloss of the new ceram.x®.