[The development of initial enamel caries--a phenomenon of interfacial reactions].

The investigation deals with earliest chemical changes in outermost enamel surfaces during initial caries development. After in vitro demineralization of enamel samples in acidulated hydroxyethylcellulose solution (pH = 5.1) for periods between 1 and 288 h the Ca/P molar ratios were determined in depths of 0.04 micron using the Rutherford Backscattering spectroscopy. The measured Ca/P ratios oscillate around the initial value. This behaviour is interpreted as a combined de/remineralization process.