title: Effect of a self-adhesive coating on the load-bearing capacity of tooth-coloured restorative materials.
abstract: BACKGROUND
  The aim of this study was to compare the flexural strength and Vickers hardness of tooth-coloured restorative materials with and without applying a self-adhesive coating for up to 6 months.
  
  
  METHODS
  Specimens were prepared from three resin composites (RC), two resin-modified glass-ionomer cements (RM-GIC) and two conventional glass-ionomer cements (CGIC). All materials were tested both with and without applying G-Coat Plus (GCP). Specimens were conditioned in 37 °C distilled deionized water for 24 h, and 1, 3 and 6 months. The specimens were strength tested using a four-point bend test jig in a universal testing machine. The broken specimen's halves were used for Vickers hardness testing. Representative specimens were examined under an environmental scanning electron microscope.
  
  
  RESULTS
  Data analysis showed that regardless of time and materials, generally the surface coating was associated with a significant increase in the flexural strength of the materials. Applying the GCP decreased the hardness of almost all materials significantly (P < 0.05) and effect of time intervals on hardness was material dependent.
  
  
  CONCLUSIONS
  The load-bearing capacity of the restorative materials was affected by applying self-adhesive coating and ageing. The CGIC had significantly higher hardness but lower flexural strength than the RM-GIC and RC.
authors.affiliation: Department of Dental Materials and Biomaterials Research Centre, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.|Restorative Section, Melbourne Dental School, The University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: R
authors.initials: R
authors.lastname: Bagheri
authors.affiliation: Restorative Section, Melbourne Dental School, The University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: Jea
authors.initials: J
authors.lastname: Palamara
authors.affiliation: Department of Prosthodontics, School of Dentistry, Dicle University, Diyarbakir, Turkey.
authors.forename: A
authors.initials: A
authors.lastname: Mese
authors.affiliation: Restorative Section, Melbourne Dental School, The University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: D J
authors.initials: DJ
authors.lastname: Manton
mesh_terms: D000269:Adhesives / Q000737:chemistry*; D003764:Dental Materials; D003793:Dental Restoration, Permanent; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006245:Hardness Tests; D006801:Humans; D008422:Materials Testing; D019279:Resin Cements / Q000737:chemistry*; D014076:Tooth Diseases / Q000601:surgery*; D017155:Wettability
chemical_list: D000269:Adhesives; D003764:Dental Materials; D005899:Glass Ionomer Cements; D019279:Resin Cements
keywords: Flexural strength; G-Coat Plus; Vickers hardness; glass-ionomer cement; resin composite