title: Characterization of Chitosan/TiO2Nano-Powder Modified Glass-Ionomer Cement for Restorative Dental Applications.
abstract: OBJECTIVE
  We are introducing novel glass-ionomer cement (GIC) dually-modified with chitosan (CH) in the liquid phase and titanium-dioxide nano-powder (TiO2/NP) in the powder phase. The aim was to investigate the effect of this dual-modification on the antibacterial properties against S. mutans biofilms and on the bulk and surface mechanical properties.
  
  
  METHODS
  Commercially available powder/liquid restorative GIC was used in this study. The GIC specimens were modified with 3% (w/w) TiO2/NP, 10% (v/v) CH solution, or dually-modified with TiO2/CH. The non-modified GIC was used as a control. The biofilms formations were characterized by SEM, live/dead assay using confocal-microscopy, colony-forming unit counts, and MTS assay. The bulk and surface mechanical properties were characterized in terms of flexural and compressive strengths and surface hardness, respectively.
  
  
  RESULTS
  With the dual-modification, a significant improvement in the antibacterial properties was found both qualitatively and quantitatively. The synergetic effect of the dual-modification was also reflected on the enhancement of the flexural and compressive strengths. However, no difference was found in surface hardness.
  
  
  CONCLUSIONS
  The modification of GIC powder with TiO2/NP showed to be more effective in enhancing the mechanical properties. However, the enhancement in the antibacterial properties was more evident with CH incorporation in GIC liquid.
  
  
  CONCLUSIONS
  This study introduced novel glass ionomer cement dually-modified with TiO2 NP and chitosan with superior mechanical and antibacterial properties for potential applications in restorative and preventive dentistry. The modification of GIC powder with TiO2 NP showed to be more effective in enhancing the mechanical properties. However, the enhancement in the antibacterial properties was more evident with CH incorporation in GIC liquid. Although of the promising synergetic effect of the dual-modification of GIC with TiO2 NP/CH, further clinically-related studies are recommended. (J Esthet Restor Dent 29:146-156, 2017).
authors.affiliation: Discipline of Prosthodontics, Operative Dentistry and Endodontics, Faculty of Dentistry, National University of Singapore, Singapore.
authors.forename: Marrwa A
authors.initials: MA
authors.lastname: Ibrahim
authors.affiliation: Discipline of Oral Sciences, Faculty of Dentistry, National University of Singapore, Singapore, 119083, Singapore.
authors.forename: Balasankar
authors.initials: B
authors.lastname: Meera Priyadarshini
authors.affiliation: Discipline of Prosthodontics, Operative Dentistry and Endodontics, Faculty of Dentistry, National University of Singapore, Singapore.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Neo
authors.affiliation: Discipline of Oral Sciences, Faculty of Dentistry, National University of Singapore, Singapore, 119083, Singapore.
authors.forename: Amr S
authors.initials: AS
authors.lastname: Fawzy
mesh_terms: D018441:Biofilms; D048271:Chitosan / Q000737:chemistry*; D003793:Dental Restoration, Permanent; D005899:Glass Ionomer Cements / Q000737:chemistry*; D008422:Materials Testing; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D036103:Nanotechnology; D011208:Powders; D014025:Titanium / Q000737:chemistry*
chemical_list: D005899:Glass Ionomer Cements; D011208:Powders; C009495:titanium dioxide; D048271:Chitosan; D014025:Titanium