title: The recharge of esthetic dental restorative materials with fluoride in vitro-two years' results.
abstract: OBJECTIVE
  A range of esthetic restorative dental materials are now available to dental clinicians. The aim of this study was to evaluate the relative fluoride recharge potential of a number of these materials in vitro over two years.
  
  
  METHODS
  Disc samples (12 mm x 2 mm) of each of the materials were placed into artificial saliva at neutral pH. The materials tested were: two glass ionomers (Chemfil; Ketac-Fil), two resin-modified glass ionomers (Photac-Fil Aplicap; Vitremer), two compomers (Dyract; Compoglass) and two composites (Heliomolar; Concise). At 13 intervals over a two years period the discs were subjected to a 2 min fluoride recharge by exposure to sodium fluoride (500 ppm F). The pre- and post-recharge fluoride release values were determined using an ion sensitive electrode.
  
  
  RESULTS
  At all time intervals the post-recharge fluoride release of the materials was significantly different (MANOVA p<0.0001). The mean values for post-recharge fluoride release after two years were: Chemfil 10.3, Ketac 3.0, Vitremer 9.0, Photac-Fil Aplicap 12.1, Compoglass 5.0, Dyract 3.6, Concise 0.3, Heliomolar 0.2 (units = microgF/cm(2)/h).
  
  
  CONCLUSIONS
  Esthetic fillings vary significantly in their capacity to absorb and re-release fluoride. The glass ionomer-based materials displayed a far greater potential for fluoride recharge than the composites, in which the recharge was virtually negligible. Whilst it cannot be assumed that fluoride release is directly proportional to cariostatic potential, these results suggest that, where possible, glass ionomer-based materials should be used in patients who have a high caries rate.
authors.affiliation: Division of Restorative Dentistry, Leeds Dental Institute, Clarendon Way, LS2 9LU, Leeds, UK. a.j.preston@leeds.ac.uk
authors.forename: Antony J
authors.initials: AJ
authors.lastname: Preston
authors.forename: Emmanuel A
authors.initials: EA
authors.lastname: Agalamanyi
authors.forename: Susan M
authors.initials: SM
authors.lastname: Higham
authors.forename: Lawrence H
authors.initials: LH
authors.lastname: Mair
mesh_terms: D000704:Analysis of Variance; D020770:Compomers / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry*; D003692:Delayed-Action Preparations / Q000737:chemistry; D003793:Dental Restoration, Permanent; D005899:Glass Ionomer Cements / Q000737:chemistry*; D017736:Ion-Selective Electrodes; D012464:Saliva, Artificial / Q000737:chemistry; D012969:Sodium Fluoride / Q000008:administration & dosage* / Q000032:analysis
chemical_list: D020770:Compomers; D003188:Composite Resins; D003692:Delayed-Action Preparations; D005899:Glass Ionomer Cements; D012464:Saliva, Artificial; D012969:Sodium Fluoride