SPECTROSCOPIC CHANGES IN HUMAN DENTIN EXPOSED TO VARIOUS STORAGE SOLUTIONS - SHORT-TERM

Objectives: Tooth storage conditions in studies of dentine have not be en standardized. The objective of this investigation was to determine the effects of storage solution and time on dentine, using spectroscop ic methods. Methods: Twenty-seven dentine disks (0.75 mm thick) were p repared from freshly extracted third molars with documented histories. The teeth were sectioned parallel to the occlusal plane using a diamo nd saw. Specimens were analysed non-destructively for surface chemical changes using specular reflectance infra-red Fourier transform spectr oscopy (SRIFTS), and changes in optical properties were measured in th e ultraviolet, visible and near-infra-red spectral ranges with an inte grating sphere spectrophotometer (UV/VIS/NIR) before and after storage . A minimum of five specimens were stored in distilled water with 0.02 % thymol, purified and filtered water, phosphate buffered saline with 0.02% thymol, 70% ethanol or 10% buffered formalin and evaluated at 0, 1, 2, 7, 14, 21 and 28 days. After each measurement, specimens were s tored in fresh solutions. IR spectra were obtained from 4400 to 400 wa ve-numbers (cm(-1)). Optical properties of reflectance and transmittan ce were determined from 200 to 2500 nm, and absorbance was calculated. Results: Analysis of the IR spectra indicated no significant differen ces in collagen or mineral peak positions for any solution at any time period. There were significant differences in peak intensities of den tine stored in distilled water, purified and filtered water and phosph ate-buffered saline over time in the IR spectra. Furthermore, differen ces in optical properties of dentine disks were detected by UV/VIS/NIR . Conclusion: It was concluded that changes in surface chemistry and o ptical properties of dentine occur as a function of storage solution a nd time, which must be considered when studying dentine. Copyright (C) 1996 Elsevier Science Ltd.