title: Evaluation of a conventional glass ionomer cement with new zinc formulation: effect of coating, aging and storage agents.
abstract: OBJECTIVE
  The study focused on a recently launched conventional glass ionomer cement (GIC) with a particular chemical formulation of both, filler and acrylic liquid, by analysing its mechanical behaviour in comparison to three conventional GICs. Furthermore, the effect of resin coating and storage conditions was evaluated.
  
  
  METHODS
  Three commercially available GICs were chosen: Riva Self Cure (SDI), Fuji IX Fast (GC) and Fuji IX GP Extra/Equia (GC). Additionally a newly developed zinc-containing GIC--ChemFil Rock (Dentsply)--was tested. Mechanical properties were determined at macro- [flexural strength (FS) and modulus of elasticity (E (flexural))] and micro-scale [Vickers hardness (VH) and indentation modulus (E)] after storing coated and uncoated specimens in artificial saliva and distilled water for 7 and 30 days.
  
  
  RESULTS
  ChemFil Rock revealed the highest FS, but the lowest VH and E. The micro-mechanical properties of the analysed GICs did neither benefit from the new zinc formulation nor from resin coating. A resin coating is nevertheless a valuable support for GIC fillings, since it offers the absence of visible surface defects like crazing and voids, and thus, it led to significant improvements in flexural strength. This statement is also valid for ChemFil Rock, contrary to manufacture recommendation. The impact of storage agent and storage duration on the measured properties was low.
  
  
  CONCLUSIONS
  The new development (ChemFil Rock) might represent a promising approach regarding longevity of GIC fillings in molar regions, due to the high flexural strength and the absence of visible surface defects like crazing and voids.
  
  
  CONCLUSIONS
  All GICs should receive surface protection in order to perform their maximum in stability.
authors.affiliation: Department of Restorative Dentistry, Dental School of the Ludwig-Maximilians-University, Goethestr, 70, 80336 Munich, Germany.
authors.forename: Julius
authors.initials: J
authors.lastname: Zoergiebel
authors.forename: Nicoleta
authors.initials: N
authors.lastname: Ilie
mesh_terms: D000179:Acrylates / Q000737:chemistry; D002626:Chemistry, Pharmaceutical; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D003799:Dental Stress Analysis / Q000295:instrumentation; D055119:Elastic Modulus; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006244:Hardness; D006801:Humans; D008422:Materials Testing; D055595:Mechanical Phenomena; D008768:Methylmethacrylates / Q000737:chemistry; D018583:Pliability; D019279:Resin Cements / Q000737:chemistry; D012464:Saliva, Artificial / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors; D014867:Water / Q000737:chemistry; D015032:Zinc / Q000737:chemistry*
chemical_list: D000179:Acrylates; D020099:Coated Materials, Biocompatible; C439808:Fuji IX GP Fast; D005899:Glass Ionomer Cements; D008768:Methylmethacrylates; D019279:Resin Cements; D012464:Saliva, Artificial; C442646:Seal and Protect resin cement; C110713:fuji IX; D014867:Water; D015032:Zinc