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 .
Marginal adaptation of class II cavities restored with bulk-fill composites.
OBJECTIVES To determine the marginal adaptation of bulk-fill composites in class II MO cavities . METHODS St and ardized class II MO cavities with bevelled enamel margins were prepared in 40 extracted human molars . The teeth were r and omly assigned to one of the five experimental groups ( n=8 ) . The teeth were restored with two horizontal increments of composite ( 4 mm and 2 mm thickness ) . The experimental groups were ( 1st/2nd increment ) : Gr . A - Venus Bulk-Fill/Venus Diamond ; Gr . B - Tetric EvoCeram BulkFill/Tetric EvoCeram ; Gr . C - Surefil SDR/Ceram-X ; Gr . D - SonicFill ; Gr . E - Ceram-X/Ceram-X ( control ) . After finishing procedures , impressions were made using a polyvinyl siloxane and epoxy resin replicas were obtained . Thermo-mechanical stressing was carried out 24h after the restorative procedure . All specimens were su bmi tted to 240,000 occlusal loading and simultaneous 600 thermal cycles in water at 5 ° C and 50 ° C . After loading , a new set of epoxy resin replicas was obtained . Scanning electron microscopy was carried out at 200 × magnification . Results for the marginal adaptation were expressed as percentages of continuity relative to the exposed interface and analyzed by ANOVA and Duncan post hoc test ( p<0.05 ) . RESULTS In enamel , no significant differences were detected before and after thermo-mechanical loading between groups . In dentine , the worst results were observed in Gr . A CONCLUSION By applying simple layering techniques , bulk-fill material s do not allow better marginal adaptation than a st and ard composite . CLINICAL SIGNIFICANCE A new class of resin-base composite ( bulk-fill ) was recently launched on the market . The bulk-fill composites exhibited adequate marginal adaptation and similar to the results of the st and ard composite
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 .