接着性レジンのうしょく象げ質内浸入に関する研究

Abstract

This study was attempted to evaluate the efficacy of the removal of the demineralized dentin layers by staining with 1.0% acid-red propylene glycol solution and to investigate the toothadhesive resin penetration into the etched dentin after the removal of carious lesion. Using vital or extracted teeth decayed to a medium degree, the prepared specimens were examined by microscopic observation, microradiography, bacterioscopy and SEM.1) By repeated staining and excavating of the decay, the dentin layers beneath the lesions gradually varied in color of red, pink and light pink. Finally, the deeper layer was not stained and coincided with the transparent zone.2) The bacteria remained in the red-stained dentin and partially in the pink-stained dentin.3) When the natural discolored dentin was thoroughly removed, the superficial layer of the transparent zone without the bacteria became exposed.4) The resin penetrated into the stained dentin or the natural discolored dentin to a length of several hundred micrometers but penetrated little into the unstained dentin or the exposed dentin after the removal of the discolored dentin.5) The resin tags produced in the stained dentin or the discolored dentin showed a smooth surface with lateral extentions and a rough surface of 1 to 1.5μm in thickness.6) The resin tags produced in the unstained dentin or the layer after the removal of the discolored dentin characteristically were of tube shape of about 10μm in length or tube containing thin projections.