The meta- analysis of the data in the included studies demonstrated that only one variable ( marginal adaptation after 12 months ) showed statistically significant outcomes , in which methacrylates-based composites presented significantly better results than resin composites containing modified monomers .
The good level of the scientific evidence as well as the overall low risk of bias of the included studies indicate that composites with silorane , ormocer or bulk-fill type modified monomers have a clinical performance similar to conventional resin composites
Polymerization shrinkage of resin composite can compromise the longevity of restorations .
To minimize this problem , the monomeric composition of composites have been modified .
The objective of this study was to conduct a meta- analysis to assess the clinical behavior of restorations performed with low polymerization shrinkage resin composite  in comparison with traditional methacrylates-based resin composite .
A prospective randomised clinical trial of one bis-GMA-based and two ormocer-based composite restorative systems in class II cavities: three-year results.
OBJECTIVES Ormocer composites , consisting of a silicon-based polymer , have been developed recently as a tooth-coloured restorative material . The purpose of this prospect i ve r and omised clinical trial was to evaluate the performance of two small-particle hybrid ormocer-based restorative systems ( AD , Admira/Admira Bond , VOCO ; DE , Definite/Etch & Prime 3.0 , Dentsply ) and one small-particle hybrid bis-GMA-based composite restorative system ( TC , Tetric-Ceram/Syntac , Ivoclar-Vivadent ) in occlusal stress-bearing restorations . METHODS One hundred and twenty-eight occlusal-proximal restorations ( 44 AD , 43 DE and 41 TC ) were placed according to the manufacturer 's instructions in thirty-two adult patients . Their clinical performance was scored according to the USPHS criteria and evaluation of bite-wing radiographs . RESULTS After 3 years , four AD , five DE and four TC restorations had failed due to fracture or marginal gap formation . Surface roughness improved significantly when compared to the baseline in AD and TC ( Friedman test , p<0.05 ) during the first year but returned to baseline values after 3 years . DE had a significant tendency towards discolouration ( p<0.05 ) . Bite-wing radiographs showed two AD and one TC restorations with internal porosities . ANOVA showed that larger restorations ( > or = 3 surfaces ) showed significantly more degradation than smaller ones . CONCLUSIONS In a group of class II restorations , there was no significant difference in failures after 3 years between ormocer-based and bis-GMA-based restorative systems
The meta- analysis of the data in the included studies demonstrated that only one variable ( marginal adaptation after 12 months ) showed statistically significant outcomes , in which methacrylates-based composites presented significantly better results than resin composites containing modified monomers .
The good level of the scientific evidence as well as the overall low risk of bias of the included studies indicate that composites with silorane , ormocer or bulk-fill type modified monomers have a clinical performance similar to conventional resin composites
Polymerization shrinkage of resin composite can compromise the longevity of restorations .
To minimize this problem , the monomeric composition of composites have been modified .
The objective of this study was to conduct a meta- analysis to assess the clinical behavior of restorations performed with low polymerization shrinkage resin composite  in comparison with traditional methacrylates-based resin composite .