BACKGROUND: The purpose of the present study was to evaluate the effect of nanofillers on the mechanical properties of 2 sizes (diameters 0.6 and 0.9 mm) of conventional and nanofilled fiber-reinforced composites (FRCs) polymerized with conventional light-curing and additional postcuring. METHODS: The FRCs samples were divided into 8 groups (10 specimens each). Conventional FRCs with glass fibers preimpregnated with polymethyl methacrylate (groups 1, 2, 3 and 4) and FRCs with impregnating solution containing 32% nanofilled resin (groups 5, 6, 7 and 8) were tested in 2 different sections (0.6 and 0.9 mm in diameter). Two different polymerizations were analyzed: hand light-curing for 40 seconds with an halogen light, and additional postcuring for 25 minutes in a light-curing oven. Each sample was evaluated with a 3-point bending test on a universal testing machine, after 48 hours of dry storage. All of the data were statistically analyzed. RESULTS: After oven postcuring, nanofilled FRCs exhibited significantly higher load values than conventional FRCs. No significant differences were found when comparing conventional and nanofilled FRCs after hand light-curing. Moreover, 0.6-mm FRCs showed significantly lower load values than 0.9-mm FRCs, both for conventional and nanofilled FRCs. CONCLUSIONS: Nanofilled FRCs showed higher load values after additional oven postcuring.
BACKGROUND: The purpose of the present study was to evaluate the effect of nanofillers on the mechanical properties of 2 sizes (diameters 0.6 and 0.9 mm) of conventional and nanofilled fiber-reinforced composites (FRCs) polymerized with conventional light-curing and additional postcuring. METHODS: The FRCs samples were divided into 8 groups (10 specimens each). Conventional FRCs with glass fibers preimpregnated with polymethyl methacrylate (groups 1, 2, 3 and 4) and FRCs with impregnating solution containing 32% nanofilled resin (groups 5, 6, 7 and 8) were tested in 2 different sections (0.6 and 0.9 mm in diameter). Two different polymerizations were analyzed: hand light-curing for 40 seconds with an halogen light, and additional postcuring for 25 minutes in a light-curing oven. Each sample was evaluated with a 3-point bending test on a universal testing machine, after 48 hours of dry storage. All of the data were statistically analyzed. RESULTS: After oven postcuring, nanofilled FRCs exhibited significantly higher load values than conventional FRCs. No significant differences were found when comparing conventional and nanofilled FRCs after hand light-curing. Moreover, 0.6-mm FRCs showed significantly lower load values than 0.9-mm FRCs, both for conventional and nanofilled FRCs. CONCLUSIONS: Nanofilled FRCs showed higher load values after additional oven postcuring.
Authors: Islam Ali Abdel Raheem; Amro Abdul Razek; Abeer Abdelaziz Elgendy; Doaa Ahmed Labah; Noha Mohamed Saleh Journal: Int J Nanomedicine Date: 2020-07-27
Authors: Maria Francesca Sfondrini; Paola Gandini; Paola Tessera; Pekka K Vallittu; Lippo Lassila; Andrea Scribante Journal: Biomed Res Int Date: 2017-10-10 Impact factor: 3.411
Authors: Andrea Scribante; Pekka K Vallittu; Mutlu Özcan; Lippo V J Lassila; Paola Gandini; Maria Francesca Sfondrini Journal: Biomed Res Int Date: 2018-10-22 Impact factor: 3.411
Authors: Andrea Scribante; Paola Gandini; Paola Tessera; Pekka K Vallittu; Lippo Lassila; Maria Francesca Sfondrini Journal: Int J Mol Sci Date: 2017-10-04 Impact factor: 5.923