[Constant composition study on kinetics of enamel demineralization].
The aim of this work was to investigate the kinetic behaviour of whole enamel demineralization compared with that of powder enamel. Constant composition technique was used to maintain a constant undersaturation degree with respect to hydroxyapatite in the demineralizing solutions. The demineralizing processes were monitored by recording the volume of adding titrant solution. Finally, sections were measured for lesion depth by microradiography, and blocks were tested for microhardness. The results showed that demineralization of enamel powder nearly completed within 40 minutes, while demineralization of whole enamel was much slower and with a constant rate within the experimental time. It was also found there were significant increases of concentrations of calcium and phosphate in solutions during the first 40 hours of whole enamel demineralization. It suggests that the kinetic behaviour of whole enamel demineralization is different from that of powder enamel, which is not only due to the unique transport process in whole tissue, but also possible due to a different phase transformation before and after formation of a surface layer.
Gao
X
X
School of Stomatology, Beijing Medical University.
Liu
Z
Z
Liu
D
D
D002118:Calcium / Q000378:metabolism; D003731:Dental Caries / Q000378:metabolism; D003743:Dental Enamel / Q000000981:diagnostic imaging / Q000378:metabolism*; D006244:Hardness; D006801:Humans; D008852:Microradiography; D010710:Phosphates / Q000378:metabolism; D017001:Tooth Demineralization / Q000378:metabolism*
D010710:Phosphates; D002118:Calcium