title: Rationale for caries inhibition of debonded glass ionomer sealants: an in vitro study.
abstract: OBJECTIVE
  This study's purpose was to test the hypothesis that, after glass ionomer (GI) sealant debonding, remaining GI in the deepest parts of fissures and/or the inhibition of enamel demineralization after artificial caries challenge imparts the residual cariostatic property observed in clinical studies.
  
  
  METHODS
  Fuji IX GI sealant was placed on one tooth from 14 matched pairs of noncarious extracted human permanent molars and premolars; the other tooth was the control. Sealed teeth underwent thermocycling (4,000 cycles), and the sealant was manually debonded. The amount of remaining sealant in the fissures was determined using a stereomicroscope. All teeth were placed in lactic acid gel (pH 5.0) at 37 degrees Celsius for three weeks to simulate caries formation. The extent of demineralization was determined using the serial micro-hardness method on the cross-sectioned specimens at 0.5 mm from the depth of the central fissure.
  
  
  RESULTS
  All teeth had GI retained in the fissures at a microscopic level. Enamel demineralization adjacent to the remaining GI was not significantly different from the control (t test; P=.88).
  
  
  CONCLUSIONS
  The residual cariostatic property of glass ionomer sealant is most likely due to a physical barrier of remaining GI in the fissures rather than a chemical effect on demineralization inhibition.
authors.affiliation: Private practice, Ft. Worth Metroplex. Dallas, Texas, USA.
authors.forename: Natalie K
authors.initials: NK
authors.lastname: Smith
authors.affiliation: Private practice, Kennewick and Richland, Wash, USA.
authors.forename: Kirk T
authors.initials: KT
authors.lastname: Morris
authors.affiliation: Department of Pediatric Dentistry and Community Oral Health, University of Tennessee Health Science Center, Memphis, Tenn., USA. mwells@uthsc.edu.
authors.forename: Martha
authors.initials: M
authors.lastname: Wells
authors.affiliation: Department of Restorative Dentistry, University of Tennessee Health Science Center, Memphis, Tenn., USA.
authors.forename: Daranee
authors.initials: D
authors.lastname: Tantbirojn
authors.affiliation: Department of Bioscience Research, College of Dentistry, University of Tennessee Health Science Center, Memphis, Tenn., USA.
authors.forename: Antheunis
authors.initials: A
authors.lastname: Versluis
mesh_terms: D002327:Cariostatic Agents / Q000737:chemistry*; D003731:Dental Caries / Q000517:prevention & control*; D017005:Dental Debonding; D003743:Dental Enamel / Q000648:ultrastructure; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006244:Hardness; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007091:Image Processing, Computer-Assisted / Q000379:methods; D019344:Lactic Acid / Q000009:adverse effects; D008422:Materials Testing; D010895:Pit and Fissure Sealants / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D017001:Tooth Demineralization / Q000517:prevention & control
chemical_list: D002327:Cariostatic Agents; D005899:Glass Ionomer Cements; D010895:Pit and Fissure Sealants; C110713:fuji IX; D019344:Lactic Acid