title: Effects of nanofillers on mechanical properties of fiber-reinforced composites polymerized with light-curing and additional postcuring.
abstract: 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.affiliation: Department of Clinical, Surgical, Diagnostic and Paediatric Sciences, Section of Dentistry, Unit of Orthodontics and Paediatric Dentistry, University of Pavia, Pavia - Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Scribante
authors.affiliation: Department of Clinical, Surgical, Diagnostic and Paediatric Sciences, Section of Dentistry, Unit of Orthodontics and Paediatric Dentistry, University of Pavia, Pavia - Italy.
authors.forename: Sarah
authors.initials: S
authors.lastname: Massironi
authors.affiliation: Department of Clinical, Surgical, Diagnostic and Paediatric Sciences, Section of Dentistry, Unit of Orthodontics and Paediatric Dentistry, University of Pavia, Pavia - Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Pieraccini
authors.affiliation: Department of Prosthetic Dentistry and Biomaterial Research, Institute of Dentistry, University of Turku, Turku - Finland.
authors.forename: Pekka
authors.initials: P
authors.lastname: Vallittu
authors.affiliation: Department of Prosthetic Dentistry and Biomaterial Research, Institute of Dentistry, University of Turku, Turku - Finland.
authors.forename: Lippo
authors.initials: L
authors.lastname: Lassila
authors.affiliation: Department of Clinical, Surgical, Diagnostic and Paediatric Sciences, Section of Dentistry, Unit of Orthodontics and Paediatric Dentistry, University of Pavia, Pavia - Italy.
authors.forename: Maria Francesca
authors.initials: MF
authors.lastname: Sfondrini
authors.affiliation: Department of Clinical, Surgical, Diagnostic and Paediatric Sciences, Section of Dentistry, Unit of Orthodontics and Paediatric Dentistry, University of Pavia, Pavia - Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Gandini
mesh_terms: D003764:Dental Materials / Q000737:chemistry*; D008027:Light; D049329:Nanostructures / Q000737:chemistry*; D010316:Particle Size; D011108:Polymers / Q000737:chemistry*
chemical_list: D003764:Dental Materials; D011108:Polymers