FTIR spectroscopy revealing the effects of laser and ionizing radiation on biological hard tissues

Abstract

This work evaluated the influence of ionizing and non-ionizing irradiations on the chemical structure of hard tissues using the mid-infrared spectroscopy. Enamel, dentin and bone slabs were submitted to gamma irradiation, as well as to Nd:YAG (λ = 1064 nm) and Er,Cr:YSGG (λ = 2078 nm) laser irradiations. The composition of slabs were evaluated by the Fourier transformed infrared spectroscopy (FTIR), considering the content of organic matrix (amides I, II and III), and inorganic matrix (phosphate and carbonate). Data were statistically analyzed (a = 5%). All irradiations altered the organic and inorganic content of enamel, dentin and bone, and the changes are dependent on the doses applied, as well as on the wavelength used considering the infrared lasers. In conclusion, the attenuated total reflection (ATR)-FTIR technique is an efficient tool to monitor the chemical changes on hard tissues due to ionizing and non-ionizing irradiations, which is important in order to choose safe parameters for a future clinical application.