Leaching of monomers from bulk-fill composites: An in vitro study

Abstract

Aim and Objectives:To evaluate the elution of bisphenol A-glycidyl methacrylate (BisGMA) and triethylene glycol dimethacrylate (TEGDMA) from two bulk-fill composites at different polymerization times, for different storage periods when cured with quartz-tungsten-halogen (QTH) curing unit.Materials and Methods:Tetric N-Ceram bulk fill and EverX Posterior were analyzed using high-performance liquid chromatography unit. Totally, 68 samples were prepared, two groups (n = 17) from both the composites, one for each tested polymerization time. Each sample was cured with a QTH curing unit, using soft-start curing technique and stored in 2 ml of ethanol for 24 h. Storage medium was renewed and then stored again for 1 week. Data acquired were statistically analyzed.Results:The elution of BisGMA was significantly higher from Tetric N-Ceram bulk fill and BisGMA and TEGDMA from EverX Posterior composite at the end of 24 h, irrespective of the curing time. In EverX Posterior, a higher amount of TEGDMA was eluted at the end of 24 h, while at the end of 1 week, significantly higher amount of BisGMA was released.Conclusion:A significant amount of the release of BisGMA as well as TEGDMA was seen from both the composites when stored for different time intervals.

Effect of layer thickness on the elution of monomers from two high viscosity bulk-fill composites: A high-performance liquid chromatography analysis

“…It was established in the present study that increase in storage period resulted in higher amount of Bis-GMA and UDMA elution for both composite 1 (Tetric EvoCeram Bulk Fill) and composite 2 (x-tra fil) at all layer thickness with highest concentrations of monomers being found in samples stored for 1 month as compared to those stored for 24 h which is in accordance with the results of study conducted by Manojlovic et al . [ 20 ] but in contrast to results obtained by Sajnani and Hegde in which maximum amount of monomer elution was observed during the first 24 h.[ 21 ]…”

Physical, mechanical, and in vitro biological analysis of bioactive fibers‐based dental composite

“…The viscoelastic behavior of reinforced glass fiber composites is comparable to dentin and these composites have shown better biocompatibility in comparison to resin‐based composites 30 . EverX posterior® (GC Europe), a commercially available short glass fiber reinforced dental composite, has shown improved depth of cure, less elution of dimethacrylates monomers, and less cytotoxic effect on gingival cells 31–33 . However, this material has no tendency to regenerate lost tooth tissue structure.…”

“…Both, HA and glass fibers (E‐glass fiber) have high refractive indexes, that is, 1.56 and 1.65, respectively, 34,35 which can affect the polymerization process, subsequently leaching of monomers, mechanical strength, and biocompatibility. The leaching of residual monomers into the oral environment has raised concerns regarding resin‐based composites 32,36 . The cytotoxicity is mainly due to the amount of unreacted monomers, which is directly related to the degree of conversion 33 .…”

Evaluation of the efficiency of polymerization of composite resins in proximal restorations

“…40 In cases of curing adhesives in deep proximal boxes with a curing light of 600 mW/cm 2 , the time should be increased to 40 to 60 seconds to ensure optimal polymerization, even for curing lights that deliver more than 1.000 mW/cm 2 . 42 In the present study, the irradiance of 1.000mW/ cm 2 formulations 26 and can be used as an intermediate in class II cavities to absorb polymerization contraction stresses 43 as well can be an alternative to packable conventional BFCs. 16 One studie 44 supported the idea that BFCs evaluated with high-and low-viscosity generate similar or lower stress values when compared to a high-viscosity conventional resin as control and contract less during polymerization, developing lower shrinkage forces compared with their conventional flowable and high-viscosity counterparts.…”

“…Different resin adhesives, placement techniques, and RBCs have been suggested to improve the clinical reliability, to control the effect of polymerization shrinkage stresses. 9,11,29,36 To guarantee the penetration of the curing light deeply enough to complete curing of RBCs 44 and to reduce stress at the cavity wall interface and, consequently, a lower gap formation at the interface, 4,33,43 the technique most used and imposed for years is the "Incremental Technique", which employs the insertion of increments with a maximum of 2mm thickness in the cavity to be restored. Appropriate light-curing is fundamental for RBCs to present satisfactory mechanical properties, providing greater clinical longevity to restoration.…”