In dentistry much research focuses on the development of procedures and materials with the aim of preventing negative effects of polymerisation shrinkage stress of composite resin. The clinical implications of shrinkage stress seem to be limited as long as correct restorative procedures are precisely followed. With the introduction of a silorane-based composite resin exhibiting a low-shrinkage behaviour the dentist is confronted with some uncertain factors. Long-term clinical studies are needed before applying these materials on a large scale.