Effect of ageing and endodontic treatment on the thermal stability of human dentin.

BACKGROUND: Human dentin is a highly calcified tissue of mesenchymal origin with a heterogeneous structure. Its morphology is constantly remodelled throughout the life span of the tooth, as well as under the influence of external stimuli. OBJECTIVE: The aim of the present study was to obtain information about the thermal changes in the crown and root dentin specimens of vital and devitalized teeth. METHODS: The investigated samples were divided into 6 groups, depending on the patients' age and dentin location (crown, root). An additional group of endodontically treated teeth was created. The methods of choice were were combined thermal analysis (DTA-TG(DTG)-MS and gas chromatography-mass spectrometry. RESULTS: After heating up to 1200 degrees C, endo- and exothermal effects were observed. The effects' dynamic was the same for all samples. The differences were in the samples' weight after the experiment, with root dentin showing the greatest mass loss percentage. CONCLUSIONS: The observed mass loss differences could be attributed to the presence of impurities in the dentin, as well as alterations in the collagen matrix. Ageing and endodontic treatment could catalyse the accumulation of such changes and affect the microstructure of the mineralized tissue.