title: Spectroscopic changes in human dentine exposed to various storage solutions--short term.
abstract: OBJECTIVE
  Tooth storage conditions in studies of dentine have not been standardized. The objective of this investigation was to determine the effects of storage solution and time on dentine, using spectroscopic methods.
  
  
  METHODS
  Twenty-seven dentine disks (0.75 mm thick) were prepared from freshly extracted third molars with documented histories. The teeth were sectioned parallel to the occlusal plane using a diamond saw. Specimens were analysed non-destructively for surface chemical changes using specular reflectance infra-red Fourier transform spectroscopy (SRIFTS), and changes in optical properties were measured in the ultraviolet, visible and near-infra-red spectral ranges with an integrating 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 stored in fresh solutions. IR spectra were obtained from 4400 to 400 wave-numbers (cm-1). Optical properties of reflectance and transmittance were determined from 200 to 2500 nm, and absorbance was calculated.
  
  
  RESULTS
  Analysis of the IR spectra indicated no significant differences in collagen or mineral peak positions for any solution at any time period. There were significant differences in peak intensities of dentine stored in distilled water, purified and filtered water and phosphate-buffered saline over time in the IR spectra. Furthermore, differences in optical properties of dentine disks were detected by UV/VIS/NIR.
  
  
  CONCLUSIONS
  It was concluded that changes in surface chemistry and optical properties of dentine occur as a function of storage solution and time, which must be considered when studying dentine.
authors.affiliation: Department of Restorative Dentistry, University of California, San Francisco 94143-0758, USA.
authors.forename: S E
authors.initials: SE
authors.lastname: Strawn
authors.forename: J M
authors.initials: JM
authors.lastname: White
authors.forename: G W
authors.initials: GW
authors.lastname: Marshall
authors.forename: L
authors.initials: L
authors.lastname: Gee
authors.forename: H E
authors.initials: HE
authors.lastname: Goodis
authors.forename: S J
authors.initials: SJ
authors.lastname: Marshall
mesh_terms: D000890:Anti-Infective Agents; D002021:Buffers; D003094:Collagen / Q000032:analysis; D003804:Dentin / Q000737:chemistry*; D000431:Ethanol; D005557:Formaldehyde; D006801:Humans; D055095:Optics and Photonics; D010710:Phosphates; D012965:Sodium Chloride; D012996:Solutions / Q000737:chemistry; D013048:Specimen Handling; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D019265:Spectroscopy, Near-Infrared; D013943:Thymol; D013997:Time Factors; D014867:Water
chemical_list: D000890:Anti-Infective Agents; D002021:Buffers; D010710:Phosphates; D012996:Solutions; D014867:Water; D005557:Formaldehyde; D013943:Thymol; D000431:Ethanol; D012965:Sodium Chloride; D003094:Collagen