Flexural Strength, Curing Depth and Shrinkage of Bulk-Fill Resin Composites.

Objectives: This study evaluated the mechanical behavior of the 3 types of Bulk Fill resin composites (BFRCs) by mechanical three-point bending test, curing depth and polymerization shrinkage.
Methods: Three types of new generation of BFRCs (Filtek One bulk fill 3M, Tetric N-Ceram Ivoclar and Aura Bulk Fill SDI) were evaluated by three-point bending test (n=10), curing depth (n=12) and polymerization shrinkage (n=5) determining the mechanical behavior of BFRCs. A one-way ANOVA multivariate test and Tukey test (α=0.05) were performed for each test.
Results: The values recorded for flexural strength in MPa were: Filtek One bulk fill 3M 98.17 (SD 28.86)A, Tetric N-Ceram Ivoclar 95.37 (SD 15.89), Aura Bulk Fill SDI 72.29 (SD 15.12)B. The exhibited curing depth in mm was: Filtek One bulk fill 3M 5.99 (SD 0.04)A, Tetric N-Ceram Ivoclar 6.00 (SD 0.04)a, Aura Bulk Fill SDI 5.68 (SD 0.03)Bb. The polymerization shrinkage in % found was: Filtek One bulk fill 3M 1.50 (SD 0.17)A, Tetric N-Ceram Ivoclar 1.96 (SD 0.04)Ba, Aura Bulk Fill SDI 2.45 (SD 0.17)Bb.
Conclusions: BFRCs showed a significant variation in some of the properties that were evaluated. The flexural strength values were significantly higher for Filtek One bulk fill than Tetric N-Ceram and Aura. The curing depth was lower in Aura Bulk Fill group. The polymerization shrinkage values were lower for 3M Bulk Fill than Tetric N-Ceram and Aura. There was no difference in the flexural modulus of the BFRCs evaluated.