Volumetric shrinkage is one of the

Volumetric shrinkage is one of the main problems causing failures and shortening the lifetime of dental resinous restorations. Owing to the compact nature of the cyclic monomer and the relatively more flexible open-chain structure, expanding monomers have demonstrated essentially zero shrinkage or expansion upon polymerization. This article reviews recent research on the new low shrinkage dental resin with spiro expanding monomers as anti-shrinkage additives. This includes the most prominent classes of expanding monomers, namely spiroorthoesters, spiroorthocarbonates and bicycloorthoester, along with mechanism of expansion polymerization. Preceded by a brief introduction of the development of copolymerization mechanism between expanding monomers and dental resin, the cutting-edge development and application of expanding monomers with different side chain groups in dental materials are introduced. Furthermore, the effect of low shrinkage resin modified by expanding monomer on the mechanical and biological properties of were indicated to be within acceptable range. The dental resin modified by spiro expanding monomers can avoid adverse impact from the volume shrinkage of polymer materials during curing. They are expected to have potential for a wide range of dental and biomedical applications to overcome the current challenges and prolong the restoration life.