Dynamic Viscoelastic Characterization of Bulk-fill Resin-based Composites and Their Conventional Counterparts

Abstract

SUMMARY This study compared the viscoelastic properties of restorative and flowable bulk-fill resin-based composites (RBCs) with their conventional counterparts and evaluated the impact of aqueous solutions on viscoelastic properties. The materials examined included three conventional RBCs (Filtek Z350, Tetric N Ceram, and Beautifil II), three restorative bulk-fill RBCs (Filtek Bulk-Fill Restorative, Tetric N Ceram Bulk-Fill, and Beautifil Bulk-Fill Restorative) in addition to three flowable bulk-fill RBCs (Filtek Bulk-Fill Flowable, Tetric N Flow Bulk-Fill, and Beautifil Bulk-Fill Flowable). Beam-shaped specimens (12×2×2 mm) were fabricated using customized stainless-steel molds, finished, and measured. The specimens were randomly divided into four groups and conditioned in air (control), artificial saliva, 0.02 N citric acid, and 50% ethanol-water solution for seven days at 37°C. They were then subjected to dynamic mechanical analysis (n = 10) in flexure mode at 37°C with a frequency of 0.1 to 10 Hz. Storage modulus, loss modulus, and loss tangent data were subjected to statistical analysis using one-way analysis of variance/Tukey post hoc test at a significance level of α = 0.05. Viscoelastic properties of the RBCs were found to be product and conditioning medium dependent. For most RBCs, exposure to aqueous solutions, particularly an ethanol-water solution, degraded viscoelastic properties. With the exception of Filtek Bulk-Fill Restorative, bulk-fill restorative and flowable RBCs generally had significantly lower storage and loss modulus than their conventional counterparts regardless of conditioning medium. Conventional RBCs are thus favored over their bulk-fill counterparts, particularly for high-stress-bearing areas.

Effects of curing modes on depth of cure and microtensile bond strength of bulk fill composites to dentin

“…However, most recent studies report data related to the former formulation, compatible with the bulk fill composites used in our study. 5 , 6 , 39 , 40 In addition, our study cannot expand on further discussion related to the potential interference of the two material composition, since they were not directly compared.…”

Influence of polymerization pressure and post-cure treatment on conversion degree and viscoelastic properties of polymer infiltrated ceramic network

“…Indeed, E ′ of enamel and dentin are reported to be between respectively 63 GPa and 14-31 GPa (Halvorson et al, 2003;Yi et al, 2020). Thus E ′ of experimental PICN at the optimal polymerization parameters (20.0-21.1 GPa) are similar to E ′ of dentin while E ′ of commercial dispersed fillers composite blocks such as Cerasmart (8.8 GPa) or Lava Ultimate (14.9 GPa) (Al-shatti et al, 2019) and E ′ of commercial conventional photopolymerized composite (4.0-7.0 GPa) (Vouvoudi and Sideridou, 2012;Yap et al, 2020) are lower. E' of commercial PICN (Enamic) was measured at 36.1 GPa.…”

Marginal Leakage Evaluation of Bioactive Bulkfill Restorative Materials in Class II Cavities: An In Vitro Comparative Study

“…6,7 The modification in bulkfill resin materials allow the application of 4-5 mm increment thickness, these modification include the chemical monomer, fillers and photoinitiator system. 8,9 Even so; despite these modifications, an absolutely marginal adaptation remain a challenge for dental clinicians. 10 Latest efforts in the development of bioactive materials may overcome this problem via their ability to form a tight seal at the interface between tooth and restoration, thus, it aimed not only substitute the lost tooth structure, but also possess therapeutic effects such as remineralization.…”