Molecular and thermal signatures of dental tissues in third molars: An in vitro comparative study using fourier-transform infrared spectroscopy and differential scanning calorimetry

Abstract

Objective: To characterize and compare the molecular and thermal characteristics of enamel, dentin, cementum, and the dentin-pulp complex in permanent third molars using Fourier-transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). Design: Samples from extracted third molars (n = 15) were prepared and analyzed using FTIR to assess molecular composition and DSC to evaluate thermal transitions, including dehydration, collagen degradation, and mineral phase transformation. All measurements were conducted in triplicate. Results: FTIR revealed enamel as highly mineralized with minimal organic content, dentin and cementum as collagen-rich, and the dentin-pulp complex as a hybrid tissue. DSC analysis identified consistent thermal transitions: water loss (110-125 degrees C), collagen breakdown (300-320 degrees C), and mineral decomposition (455-470 degrees C). Enamel displayed the highest crystallinity, while cementum exhibited the highest enthalpy change. Tissues with stronger FTIR collagen peaks corresponded to higher DSC energy release during protein degradation. Conclusion: Molecular and thermal profiling of dental tissues provide baseline reference data for biomaterial design and regenerative strategies. Clinical significance: Understanding tissue-specific molecular and thermal properties can guide the development of biomimetic restorative materials, inform safer thermal thresholds during clinical procedures, and support diagnostic approaches for aging and pathological changes.