Effect of random/aligned nylon-6/MWCNT fibers on dental resin composite reinforcement.
The aims of this study were (1) to synthesize and characterize random and aligned nanocomposite fibers of multi-walled carbon nanotubes (MWCNT)/nylon-6 and (2) to determine their reinforcing effects on the flexural strength of a dental resin composite. Nylon-6 was dissolved in hexafluoropropanol (10 wt%), followed by the addition of MWCNT (hereafter referred to as nanotubes) at two distinct concentrations (i.e., 0.5 or 1.5 wt%). Neat nylon-6 fibers (without nanotubes) were also prepared. The solutions were electrospun using parameters under low- (120 rpm) or high-speed (6000 rpm) mandrel rotation to collect random and aligned fibers, respectively. The processed fiber mats were characterized by scanning (SEM) and transmission (TEM) electron microscopies, as well as by uni-axial tensile testing. To determine the reinforcing effects on the flexural strength of a dental resin composite, bar-shaped (20×2×2 mm(3)) resin composite specimens were prepared by first placing one increment of the composite, followed by one strip of the mat, and one last increment of composite. Non-reinforced composite specimens were used as the control. The specimens were then evaluated using flexural strength testing. SEM was done on the fractured surfaces. The data were analyzed using ANOVA and the Tukey׳s test (α=5%). Nanotubes were successfully incorporated into the nylon-6 fibers. Aligned and random fibers were obtained using high- and low-speed electrospinning, respectively, where the former were significantly (p<0.001) stronger than the latter, regardless of the nanotubes׳ presence. Indeed, the dental resin composite tested was significantly reinforced when combined with nylon-6 fibrous mats composed of aligned fibers (with or without nanotubes) or random fibers incorporated with nanotubes at 0.5 wt%.
Indiana University School of Dentistry - Department of Restorative Dentistry/Division of Dental Biomaterials 1121 W. Michigan Street, Indianapolis, IN 46202, USA; Universidade Estadual Paulista (UNESP), Institute of Science and Technology, São José dos Campos Dental School, Department of Dental Materials and Prosthodontics, São José dos Campos, São Paulo, Brazil.
Alexandre L S
ALS
Borges
Indiana University School of Dentistry - Department of Restorative Dentistry/Division of Dental Biomaterials 1121 W. Michigan Street, Indianapolis, IN 46202, USA; Graduate Program in Dentistry, Federal University of Pelotas, Pelotas, RS 96065-100, Brazil.
Eliseu A
EA
Münchow
Universidade Estadual Paulista (UNESP), Institute of Science and Technology, São José dos Campos Dental School, Department of Dental Materials and Prosthodontics, São José dos Campos, São Paulo, Brazil.
Ana Carolina
AC
de Oliveira Souza
Indiana University School of Dentistry - Department of Restorative Dentistry/Division of Dental Biomaterials 1121 W. Michigan Street, Indianapolis, IN 46202, USA.
Takamitsu
T
Yoshida
Department of Biomaterials Science, Turku Clinical Biomaterials Centre-TCBC, Institute of Dentistry, University of Turku and City of Turku, Division of Welfare Division, Turku, Finland.
Pekka K
PK
Vallittu
Indiana University School of Dentistry - Department of Restorative Dentistry/Division of Dental Biomaterials 1121 W. Michigan Street, Indianapolis, IN 46202, USA. Electronic address: mbottino@iu.edu.
Marco C
MC
Bottino
D000180:Acrylic Resins / Q000737:chemistry*; D002209:Caprolactam / Q000031:analogs & derivatives / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D004548:Elasticity; D008422:Materials Testing; D053761:Nanocomposites / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D011140:Polyurethanes / Q000737:chemistry*; D013499:Surface Properties
D000180:Acrylic Resins; C029012:Composite Dental Resin; D003188:Composite Resins; D003764:Dental Materials; D011108:Polymers; D011140:Polyurethanes; C009916:nylon 6; D002209:Caprolactam
Composite resin; Fiber reinforcement; MWCNT; Nanofibers; Nylon-6