IADR Abstract Archives
Flexural Property Comparison of UDMA-Based and Bis-GMA-Based Composites
Objectives: The majority of current restorative composite resins contain Bis-GMA, a bis-phenol A (BPA)-derived monomer. Due to growing health concerns regarding BPA exposure, composites containing other monomers including UDMA have been developed. The objective was to evaluate the flexural properties of two commercially-available UDMA-based universal composites marketed as BPA-free compared to a commercially-available Bis-GMA-based universal composite.
Methods: Beam specimens (25x2x2 mm; N=10/material) of Filtek Supreme Ultra (FSU; Bis-GMA), Gradia Direct X (GDX; UDMA), and Venus Diamond (VD; UDMA) were incubated for 24 hrs in sterile H2O at 37°C prior to a 3-point bend test to measure flexural properties. An SEM qualitative fractographic analysis of representative specimens was done to characterize filler morphology and identify differences in the failure fracture as a function of material.
Results: All three materials differed significantly (p<0.05) from one another in terms of flexural strength with VD (148±7MPa) > FSU (120±15MPa) > GDX (82±8MPa). For flexural modulus, FSU (9.34±0.49GPa) and VD (9.40±0.68GPA) were similar to each other, while GDX (5.02±0.12GPa) was significantly lower (p<0.5). From the SEM analysis, FSU had round, uniform fillers with fracture occurring through the resin. GDX included irregularly-shaped filler particles as well as some large pre-polymerized resin particles with fracture failure at the interface between pre-polymerized resin filler particles and resin. VD included smaller round particles and large jagged particles with fracture through resin as well as through larger filler particles.
Conclusions: Based on flexural properties, VD (UDMA) appears to be a viable universal alternative to Bis-GMA universal composites such as FSU, while the lower properties of GDX (UDMA) could be a concern for a universal material. As more UDMA-based composites become commercially available, additional evaluations are needed to ensure flexural properties are optimal for the intended material application. Funded by UMKC SOD Summer Scholars Program.
Methods: Beam specimens (25x2x2 mm; N=10/material) of Filtek Supreme Ultra (FSU; Bis-GMA), Gradia Direct X (GDX; UDMA), and Venus Diamond (VD; UDMA) were incubated for 24 hrs in sterile H2O at 37°C prior to a 3-point bend test to measure flexural properties. An SEM qualitative fractographic analysis of representative specimens was done to characterize filler morphology and identify differences in the failure fracture as a function of material.
Results: All three materials differed significantly (p<0.05) from one another in terms of flexural strength with VD (148±7MPa) > FSU (120±15MPa) > GDX (82±8MPa). For flexural modulus, FSU (9.34±0.49GPa) and VD (9.40±0.68GPA) were similar to each other, while GDX (5.02±0.12GPa) was significantly lower (p<0.5). From the SEM analysis, FSU had round, uniform fillers with fracture occurring through the resin. GDX included irregularly-shaped filler particles as well as some large pre-polymerized resin particles with fracture failure at the interface between pre-polymerized resin filler particles and resin. VD included smaller round particles and large jagged particles with fracture through resin as well as through larger filler particles.
Conclusions: Based on flexural properties, VD (UDMA) appears to be a viable universal alternative to Bis-GMA universal composites such as FSU, while the lower properties of GDX (UDMA) could be a concern for a universal material. As more UDMA-based composites become commercially available, additional evaluations are needed to ensure flexural properties are optimal for the intended material application. Funded by UMKC SOD Summer Scholars Program.