| Co-Investigator(Kenkyū-buntansha) |
YOSHINO Norio Tokyo University of Science, Industrial Chemistry, Professor, 工学部, 教授 (50084380)
KURATA Shigeaki Kanagawa Dental College, Biomaterials and Devises, Assistant Professor, 歯学部, 助教授 (20104333)
KONDO Yukishige Tokyo University of Science, Industrial Chemistry, Assistant Professor, 工学部, 講師 (70277276)
|
|---|
| Research Abstract |
We have considered that decreasing the surface free energy of tooth surface may contribute to prevention of caries and periodontal disease. We have synthesized the novel hybrid surfactants named sodiuml-[(4hepta- decafluorooct1)-1-hexyl-phenyl phosphate (F8H5PPhNa), sodium1-[(4heptadecafluorooctyl)phenyl]-1-butylphenyl phosphate (F8H3PPhNa), 1H,1H,2H,2H-perfluorohexylphenylphosphoric acid (F4), 1H,1H,2H,2H-perfluorooctyl phenyl phosphoric acid (F6), and 1H,1H,2H,2H-perfluorodecyl phenyl phosphoric acid (F8) containing a fluorocarbon chain and hydrocarbon chain in a molecule. The aim of this study was to investigate the surface free energy and the acid resistance of the enamel surface treated with novel hybrid surfactants.
Smoothly finished bovine enamel surface was modified with F8H5PPhNa, F8H3PPhNa prepared to 1mmol/l with distilled water, and with a 20mmol/l of F4, F6 or F8/5% ethanol. The surface free energies were computed using the Drop Method. In order to evaluate water-proof of the modified surface, the enamel specimens were stored in water at 37℃ for 1, 3, 7, 14, 21, 28, 60, and 90 days. The specimens were immersed in a 0.1 mol/l of sodium acetate buffer of pH4.0 for 30min and the amounts of Ca^<2+> was measured by atomic absorption analysis.
The surfaces of specimens were observed by SEM.
The surface free energy of modified by these surfactants were significantly lower than the control (p<0.05). However, the surface free energies of all groups were increased after 3-day storage in water. The amounts of Ca^<2+> dissolved from modified groups were less than control (p<0.05). The F8 modified group was a quarter of that of the control and the lowest of the groups (p<0.01). The F8 modified enamel surface also showed less decalcification compared with that of the control by SEM observation.
From these results, it was suggested that the novel hybrid and aqueous surfactants i.e.F8 is promising to prevent plaque accumulation on the enamel surface.
|
