Abstract
The variation of polymerization shrinkage stress with time for 26 experimental composite resins applied on one surface of a thin glass beam has been determined.In addition, the amount of polymerization shrinkage of these materials during setting was investigated using a small glass cell and an electric strain transducer(UL-50).From these results, the effects of filler shape, filler particle size and filler content on shrinkage stress during setting were discussed.The increase of filler content in the material enlarged the deflection(shrinkage stress)of the glass beam and reduced the amount of linear shrinkage during setting.Furthermore, this shrinkage stress also decreased with the use of a larger filler in an average particle size.In cases using the same filler content materials, the effects of filler shape(irregular or spherical filler)on shrinkage stress was not recognized in this experiment.
