Collagen absorption bands in heated and rehydrated dentine

The objective of this work is identifying changes in the collagen bands in heated and rehydrated dentine. We use bovine dentine slices that were heated in oven between 100 and 300 °C. The sample hydration was conducted in sodium chloride solution at 0.9 wt.%; the spectra were acquired by a Fourier transform infrared spectrometer in the spectral range of 4000-400 cm−1. Our results show a temperature range (T ≤ 175 °C) where the dentinal collagen can be partially denatured and reverted to initial conformation; a second region (175 °C < T ≤ 225 °C) where this process occurs partially and a third region (T > 225 °C) where the collagen is denatured and no reversion is observed after rehydration. This work identifies an important characteristic that dentinal collagen can assume when the tissue is heated and rehydrated; these results indicate the denaturation temperature of dentinal collagen to be near 175-200 °C.