When we say ceramic fillings, we actually consider a ceramic inlays (solution similar to composite fillings but with much higher quality), ceramic onlays (ceramic fillings that include top teeth) and partial dental crowns. The difference between onlays and partial crowns is that the crown always includes at least one side of the tooth, and onlay does not.
By using ceramic fillings we can completely reconstruct a tooth that has been devastated by caries, fractures or old amalgam fillings, in a way which protects a tooth maximally, i.e. without scraping. Instead of ceramic fillings, which in 2015 we get in a few minutes with CEREC machine, we had to choose between dental crowns, for which it is necessary to reduce the weight of tooth fillings, and large fillings, that cannot last for long. It is evident that the ceramic fillings are the best solution that modern dentistry knows when it comes to a restoration of natural teeth.
Why are ordinary white fillings an insufficiently good solution?
Standard white fillings (formerly were used amalgam gray, but that is already history) may be more or less technologically advanced, in a way that it may contain nano particles or ceramics, but thing that they all share is that they have a density of plasticine and are becoming harden only after application in layers, and with hardening and brightening with light. All fillings change over time, weaken between the joints, crack, change color and sometimes fall out, and this is due to a composition and procedures of making. When brightening fillings with a lamp, i.e. hardening, it comes to a contraction of filling and loosening between fillings and teeth, so the greater the filling (i.e. the larger the cavity in a tooth), it is higher the percentage of shrinkage of future filling.
Since ceramic filling is non-composite, e.g. it is obtained by cutting pieces of a homogeneous ceramic cube, so shrinkage simply does not exist. At first glance, a white filling has the advantage of being soft and can perfectly fill the cavity, but since the ceramic filling has been made in the CEREC machine based on a computer scanning of teeth, a firm filling can perfectly cover the cavity and it will not leave a tenth of a millimeter between teeth and filling, while the minimum space between teeth and filling is filled by cementing. For dental health, aesthetics and functionality of a filling it is very good that the minimum amount of cement is required, and all this is due to CAD/CAM technology, which allows us to scan tooth three-dimensionally and to leave the machine to precisely make a filling by the measures obtained by scanning.