Polymerization Stress and Mechanical Properties of Bulk-fill Resin Composite Containing Supra-nano Spherical Filler

Objectives: The objective of this study was to compare the polymerization stress and mechanical properties of bulk-fill resin composite and to assess the effect of the supra-nano spherical filler.
Methods: The following four bulk-fill resin composites were used: SureFil SDR (SF, Dentsply Caulk, microhybrid filler); Filtek Bulk Fill (FB, 3M ESPE, microhybrid); Venus Bulk Fill (VB, Hereus Kulzer, nanohybrid filler); experimental bulk-fill (EBF-001, Tokuyama Dental Corporation, supra-nano spherical filler). Shrinkage stress was measured using a universal testing machine (n=3) (Auto Graph, AG-5000D, SHIMADZU, Japan). Flexural strength (FS) was determined according to ISO 4049 (n=5). Vickers Hardness Numbers (VHN) ratio of top and bottom surface was measured using micro hardness tester (n=3) (MMT-X7, MATSUZAWA, Japan, 4mm height, bottom VHN / top VHN). Each resin composite was cured for the time instructed by the manufacturer (SF, FB, VB: 20 seconds, EB: 10 seconds) with LED light-curing unit (Eliper S10, 3M ESPE, 600mW/cm²). The Data was submitted to one-way ANOVA with Turkey ‘s HSD (p<0.05).
Results: The following table shows PSS, FS and VHN ratio of the bulk fill resin composites.
Conclusions: The bulk-fill resin composite with the supra-nano spherical filler showed low shrinkage stress, high flexural strength and high VHN ratio, while curing time was shortest.