engleski

The effect of curing mode of a high-power LED unit on dentin bond strength

Introduction: The aim was to investigate the effects of curing mode with a high-power LED curing unit in terms of shear bond strength (ISO 29022) of bulk composite bonded to dentin using universal adhesive. Materials and Methods: To create flat bonding substrates ; a mid-coronal section of tooth was made using a low-speed saw, dentin surface was embedded in an acrylic resin and wet-polished. Composite cylinders studs of four bulk composite materials (n=15) ; Tetric Power Fill, Tetric Power Flow (Ivoclar Vivadent), Filtek One (3M), SDR Plus (Dentsply Sirona) were bonded upon dentin substrates using universal adhesive Scotchbond Universal Plus (3M). In the first group, adhesive was cured using Bluephase PowerCure unit (Ivoclar Vivadent) for 20 s (1, 200 mW/cm2) and bulk materials were polymerized with 3 s mode (3, 000 mW/cm2), while in the second group composites were cured using 20 s mode. Specimens were stored at 37 °C in distilled water and fractured in shear mode after 1 month. Results: The highest bond strength was identified for Tetric Power Flow using 20 s mode (26, 75 MPa), whilst the lowest bond strength was observed for Filtek using 20 s mode (15, 52 MPa). A statistically significant effect of the curing protocol was identified only for Tetric Power Flow, which showed significantly lower bond strength for the 3 s protocol. Conclusions: In the experimental model adopted for this study, specimens polymerized with a high- power LED curing unit in 3 s mode didn't significantly differ in shear bond strength compared with specimens cured with 20 s mode except Tetric Power Flow. Keywords: dentin bond strength, shear bond strength, curing mode, high-power LED

dentin bond strength ; shear bond strength ; curing mode ; high-power LED

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