Abstract
The purpose of this report was to learn about the influence of the loss of pit and fissure sealant by abrasion.
As a preliminary study, we investigated the similarity of the abrasive change of the sealant in vivo and by means of the abrasion test with glass beads, by comparing the change of the surface contour.
For comparison, replicas were obtained longitudinally from the tooth with sealant. They were standardized in position using of the three-dimensional repositioner to observe the same area for each replica. The abrasive change at the same area of the sealant was measured with the surface contour analyzer.
After the abrasion test, the experimental tooth was cut off bucco-lingually at the terminal end of the fissure where the sealant material had disappeared. The section was observed by means of a scanning electron microscope.
We obtained the following findings from this study;
1) Both the sealant and the tooth material were lost by this glass bead abrasion test, and the most obviously loss was observed at the border between the sealant and the tooth surface. Such abrasive change was very similar to the intraoral change of the sealant.
2) Because of the similarity of the abrasive change between in vivo and the experimental findings, the abrasion test with glass beads was found to be a good test method producing the longitudinal change of the sealant similar to that seen in the mouth.
3) The observation by a scanning electron microscope revealed that the thin layer of sealant and resin tag remained at the terminal end of the fissure that was visibly exposed by sealant loss. The effect of preventing dental caries was thought to be maintained after visible sealant loss based on this finding.
