Nanotechnology in dental restoratives
There have been significant changes in the use of dental restorative materials in the last 10-20 years. Direct and indirect tooth-coloured restorations are an alternative to standard amalgam, for which the potential health risks have been strongly debated. Especially the direct restorations with plastic restorative materials (composite, compomers and Ormocer®s) have achieved a dominant position.
The conventional composites differ substantially among themselves by the type and size of the filler used. Filler with an average particle size of ca. 10 µm is used in macro-filler composites, which represent the first phase of development and thus the oldest representative of tooth-coloured, plastic restoratives.
Since large particles have an excellent surface/volume ratio, relatively highly-filled composites with good shrinkage values are the result. Unfortunately, these materials exhibit average fracture resistance and insufficient abrasion resistance, due to the inhomogeneity between the resin matrix and fillers. Furthermore, they are difficult to polish, so that they are suitable only to a limited degree for use in the anterior area.