Kombinierte Elektronenbeugungs- und "electron probe x-ray microanalysis"-Untersuchungen an Frühstadien der Zahnsteinbildung
Zeitschrift für Naturforschung. B, A journal of chemical sciences
1) From new calculus-formations, deposited on Mylar foils within 4 - 12 days, ultrathinsections were taken after alcohol-fixation. In the electronmicroscopical microanalyzer of Duncumb (5) we carried out Ca/P-measurements as well as relative-quantitative Ca- und P-determinations in microareas of mineralized and unmineralized tissue. 2) From the same person, 1 - 12 days after cleaning of the teeth, we also took the calculusformations, transfered them on Nylon foils, evaporated them with Al and
... them with Al and carried out full quantitative Ca- und P-measurements in a normal microprobe. Concerning 1) our Ca/P values of partly mineralized microareas of the 4 days-foil are in the range of 0.95 - 1,3 and are far below the Ca/P molar ratio of apatite (1,67). Also the Ca/P ratios of mineralized microareas of older formations (e.g. 12 days) were found to ly normally below apatitic. The Ca/P-ratios of the neighbouring unmineralized microareas normally were even below those of the mineralized ones and increased with increasing Ca- and P-enrichment in the tissue. From this we conclude that Ca-enrichment in the tissue is the important step leading to nucleation which causes a further P-enrichment above the normal P-level in the tissue (probably by binding of HPO4-groups). This conclusion is supported by most of the results of 2).