title: Physicochemical and bioactive properties of innovative resin-based materials containing functional halloysite-nanotubes fillers.
abstract: This study aimed to assess the degree of conversion, microhardness, solvent degradation, contact angle, surface free energy and bioactivity (e.g., mineral precipitation) of experimental resin-based materials containing, pure or triclosan-encapsulated, aluminosilicate-(halloysite) nanotubes.
  
  
  
  An experimental resin blend was prepared using bis-GMA/TEGDMA, 75/25wt% (control). Halloysite nanotubes (HNT) doped with or without triclosan (TCN) were first analyzed using transmission electron microscopy (TEM). HNT or HNT/TCN fillers were incorporated into the resin blend at different concentrations (5, 10, and 20wt%). Seven experimental resins were created and the degree of conversion, microhardness, solvent degradation and contact angle were assessed. Bioactive mineral precipitation induced by the experimental resins was evaluated through Raman spectroscopy and SEM-EDX.
  
  
  
  TEM showed a clear presence of TCN particles inside the tubular lumen and along the outer surfaces of the halloysite nanotubes. The degree of conversion, surface free energy, microhardness, and mineral deposition of polymers increased with higher amount of HNTs. Conversely, the higher the amount (20wt%) of TCN-loaded HNTs the lower the microhardness of the experimental resins.
  
  
  
  The incorporation of pure or TCN-loaded aluminosilicate-(halloysite) nanotubes into resin-based materials increase the bioactivity of such experimental restorative materials and promotes mineral deposition. Therefore, innovative resin-based materials containing functional halloysite-nanotube fillers may represent a valuable alternative for therapeutic minimally invasive treatments.
authors.affiliation: Laboratório de Materiais Dentários, Faculdade de Odontologia, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2492, Rio Branco, 90035-003 Porto Alegre, Brazil. Electronic address: fdegrazia@hotmail.com.
authors.forename: Felipe Weidenbach
authors.initials: FW
authors.lastname: Degrazia
authors.affiliation: Laboratório de Materiais Dentários, Faculdade de Odontologia, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2492, Rio Branco, 90035-003 Porto Alegre, Brazil. Electronic address: vicente.leitune@ufrgs.br.
authors.forename: Vicente Castelo Branco
authors.initials: VC
authors.lastname: Leitune
authors.affiliation: Departamento de Engenharia Metalúrgica, Escola de Engenharia, Universidade Federal do Rio Grande do Sul, Av. Osvaldo Aranha, 99, Centro, 90035-190 Porto Alegre, Brazil. Electronic address: antonio.takimi@gmail.com.
authors.forename: Antonio Shigueaki
authors.initials: AS
authors.lastname: Takimi
authors.affiliation: Laboratório de Materiais Dentários, Faculdade de Odontologia, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2492, Rio Branco, 90035-003 Porto Alegre, Brazil. Electronic address: fabricio.collares@ufrgs.br.
authors.forename: Fabrício Mezzomo
authors.initials: FM
authors.lastname: Collares
authors.affiliation: Departamento de Odontología, Facultad de Ciencias de la Salud, Universidad CEU-Cardenal Herrera, C/Del Pozo s/n, Alfara del Patriarca, 46115 Valencia, Spain. Electronic address: salvatore.sauro@uch.ceu.es.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Sauro
mesh_terms: D000538:Aluminum Silicates; D017438:Bisphenol A-Glycidyl Methacrylate; D000077215:Clay; D003764:Dental Materials; D008422:Materials Testing; D046529:Microscopy, Electron, Transmission; D043942:Nanotubes; D012117:Resins, Synthetic
chemical_list: D000538:Aluminum Silicates; D003764:Dental Materials; D012117:Resins, Synthetic; D017438:Bisphenol A-Glycidyl Methacrylate; D000077215:Clay
keywords: Bioactivity; Nanotubes; Physicochemical properties; Resin composite; Triclosan