Root Dentin Analysis from using Fourier-Transform Infrared Spectroscopy with Attenuated Total Reflectance (FTIR-ATR)

Dentin is the structure that greatly influences the teeths resistance to masticatory forces in both norm and pathology. The aim of our study was to determine the changes that take place in samples of root dentin in vital and devitalized teeth using FTIR-ATR. The samples used were taken from young root dentin, old root dentin and root dentin from endodontically treated teeth (ETT). The investigations were conducted using an infrared spectrometer FTIR Tensor 37 Bruker in the middle infrared spectre (400 4000 cm-1) with an ATR sensor attachment. The spectroscopic images obtained showed typical spectres for dentin, with absorbance peaks between 800 3500/cm-1. The results showed that the hydroxyapatite content in root dentin is decreased and the collagen structure is changed. Aging and endodontic treatment could lead to changes in root dentin that affect both the hydroxyapatite and the collagen structure. Therefore, endodontic treatment could potentiate mechanisms, similar to those observed during the physiologycal aging of dentin. In contrast to aging though, the process is sped up and affects mainly the root dentin.