title: In vitro caries inhibition at the enamel margins of glass ionomer restoratives developed for the ART approach.
abstract: OBJECTIVE
  To assess the ability of conventional glass ionomer cements manufactured specifically for the atraumatic restorative treatment (ART) approach to inhibit the in vitro demineralization of enamel.
  
  
  METHODS
  Twenty-four sound permanent premolar teeth, extracted for orthodontic reasons, had cervical cavities (4x2x1. 5mm(3)) prepared in enamel. These were restored with Fuji IX, Fuji IX GP, Ketac-Molar and Compoglass, and then thermocycled 300 times between 5-55 degrees C before being placed in a demineralizing solution (0.1M lactic acid with 1g/l dissolved hydroxyapatite at pH 4.7) for four weeks. Buccolingual planoparallel sections were cut axially through the restorations, and subsequently lapped to approximately 100 microm thickness. The sections were examined with a polarized light microscope, and lesion measurements made using image analysis software. ANOVA and coefficients of variance were used to compare the findings.
  
  
  RESULTS
  Compoglass and Ketac-Molar showed significantly less surface erosion than did the other two cements (p<0.0001). Inhibition of enamel demineralization immediately adjacent to the restoration margins was more frequent with the glass ionomer cements (20.5-25.0%) than with Compoglass (13.0%). However, the widths of the inhibition zones varied between materials and sites.
  
  
  CONCLUSIONS
  Fluoride ion release from the restorative materials afforded some degree of protection to the adjacent enamel against in vitro demineralization.
authors.affiliation: Conservative Dentistry, The University of Hong Kong, Prince Philip Dental Hospital, 34 Hospital Road, Hong Kong, People's Republic of China. roger.smales@adelaide.edu.au
authors.forename: R J
authors.initials: RJ
authors.lastname: Smales
authors.forename: W
authors.initials: W
authors.lastname: Gao
mesh_terms: D000704:Analysis of Variance; D002327:Cariostatic Agents / Q000008:administration & dosage; D003188:Composite Resins; D003743:Dental Enamel; D003793:Dental Restoration, Permanent / Q000379:methods*; D003936:Diagnosis, Computer-Assisted; D005459:Fluorides / Q000008:administration & dosage; D005899:Glass Ionomer Cements / Q000737:chemistry*; D007091:Image Processing, Computer-Assisted; D018709:Statistics, Nonparametric; D017001:Tooth Demineralization / Q000517:prevention & control*
chemical_list: D002327:Cariostatic Agents; C105428:Compoglass; D003188:Composite Resins; D005899:Glass Ionomer Cements; C110713:fuji IX; C110712:ketac-molar; D005459:Fluorides