Abstract
Flowable resin composites have been developed for high flowability and have been used for the filling of pit and fissure caries, cervical lesions such as wedge-shaped defects and root surface caries. To obtain good flowability and easy handling properties, the inorganic filler contents should be decreased and diluent monomers increased, but there is concern that these modifications might lead to deteriorated mechanical properties and increased polymerization shrinkage. This study evaluated inorganic filler contents, polymerization shrinkage and viscoelasticity of flowable resin composites. Filler contents ranged from42.5to78.6wt% and polymerization shrinkage ranged from2.16to4.04 vol%. Polymerization shrinkage correlated to inorganic filler contents. The viscosity coefficient ranged from21 to144Pa·s and complex viscosity coefficient ranged from20 to 54 Pa·s. There was no correlation between inorganic filler contents and viscosity of flowable resins. From SEM observations, flowable resin composites were classified into three groups by their type of filler.