Raman spectroscopic characterisation of resin-infiltrated hypomineralised enamel.

Raman spectroscopy was used to investigate how the effect of pre-treatment protocols, with combinations of hydrochloric acid (HCl), sodium hypochlorite (NaOCl) and hydrogen peroxide (H2O2), for molar-incisor hypo-mineralisation (MIH) altered the penetration depth of polymer infiltrants (ICON, DMG, Hamburg, Germany). Furthermore, the effect on the structure of the MIH portions of the teeth with treatment is examined using multivariate analysis of spectra. It was found that pre-treatment protocols improved penetration depths. The structure of the MIH portion post-treatment appeared much closer to that of normal enamel suggesting a diminution of protein in the MIH region with treatment.

Elemental and chemical characterization of dolphin enamel and dentine using X-ray and Raman microanalyzes (Cetacea: Delphinoidea and Inioidea).

Dolphins show increased tooth number and simplified tooth shape compared to most mammals, together with a simpler ultrastructural organization and less demanding biomechanical function. However, it is unknown if these factors are also reflected in the chemical composition of their teeth. Here, the bulk chemical composition and elemental distribution in enamel and dentine of extant dolphins were characterized and interpreted using X-ray and spectroscopy techniques. Teeth of 10 species of Delphinida were analyzed by WDX, EDX and Raman spectroscopy. For most of the species sampled, the mineral content was higher in enamel than in dentine, increasing from inner towards outer enamel. The transition from dentine to enamel was marked by an increase in concentration of the major components Ca and P, but also in Na and Cl. Mg decreased from dentine to enamel. Concentrations of Sr and F were often low and below detection limits, but F peaked at the outer enamel region for some species. Raman spectroscopy analyzes showed characteristics similar to carbonated hydroxyapatite, with the strongest peak for the phosphate PO4(3-) stretching mode at 960-961cm(-1). Dentine samples revealed a higher diversity of peaks representative of organic components and proteins than enamel. The similar distribution pattern and small variation in average concentration of major and minor elements in dentine and enamel of dolphins suggest that they are subject to strong physiological control. A clear trend of the elemental variations for all dolphin species sampled suggests that the general pattern of tooth chemistry is conserved among the Mammalia.

Raman imaging of drug delivery systems.

This review article includes an introduction to the principals of Raman spectroscopy, an outline of the experimental systems used for Raman imaging and the associated important considerations and limitations of this method. Common spectral analysis methods are briefly described and examples of interesting published studies which utilised Raman imaging of pharmaceutical and biomedical devices are discussed, along with summary tables of the literature at this point in time.

Interaction of bioactive glass with clodronate.

Bone tissue engineering is a rapidly growing area of research involving the use of bioactive glass (BG) alone and in combination with different materials. The objective of this study was to investigate the interaction of BG with clodronate. Characterisation of the interaction between BG and clodronate was undertaken using; scanning electron microscopy (SEM), X-ray powder diffraction (XRPD), Fourier transform Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR). The interaction was examined in vitro with respect to the ion exchange and surface modification on the surface of the bioactive glass in the combination product. The results showed clear ion exchange enhancement by clodronate. Additionally, this ion exchange was more extensive and long lasting in the combination product than in BG alone. Clodronate promotes the activity of the BG and a calcium clodronate precipitation is formed. It can be assumed that this solid combination could be used in clinical applications. Therefore, it can be concluded that clodronate makes a beneficial environment for BG and could enhance also the apatite formation of BG.