In order to develop a self-etching sealant which does not contain either ethanol or water, a basic study was conducted.
As the first step, an experimento n the dissolution of hydroxyapatite of which the teeth are mainly composed was carried out, to investigate the etching ability of newly prepared sealant which consisted of phosphate monomer.
The following results were obtained, which indicated that the all-in-one-system sealant can be an alternative material as a sealant.
1) The experimental sealant containing phosphate monomer was able to dissolve hydroxyapatite in a dry condition.
2) During the early reaction stage, the dissolution depended largely on the dampness of the hydroxyapatite.
The amount of wet hydroxyapatite dissolved to the experimental sealant#1 (phosphate monomer: dilution monomer=5: 5) or sealant#2 (2: 8) was 9 times or 18 times more than the dry apatite respectively for the first one hour.
3) The amount of dissolution was dependent on the phosphate monomer content.