Comparative Evaluation of the Effect of Heat on Physical and Chemical Properties With Thermodynamic Profile of Six Endodontic Sealers – an in Vitro Study

Background: Warm obturation techniques using thermoplasticized gutta-percha are widely used in endodontics to improve adaptation and three-dimensional sealing of the root canal system. However, heat generated during these procedures may influence the physical, chemical, and thermodynamic properties of endodontic sealers, potentially affecting their clinical performance. Owing to the compositional diversity of contemporary sealers, their response to thermal stress may vary, necessitating systematic evaluation . Methodology: Six commercially available endodontic sealers were evaluated using Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) to assess thermal behaviour and stability. Surface morphology and elemental composition were analysed using Scanning Electron Microscopy (SEM) and Energy-Dispersive Spectrometry (EDS) at room temperature and after standardized heat exposure. Results: Thermal analysis demonstrated material-dependent behaviour. Groups A, D, and F exhibited greater thermal stability, while Groups B, C, and E showed higher thermal sensitivity. None of the sealers decomposed up to 250 °C. Minimal mass loss was observed, with greater changes in resin-based sealers. SEM revealed more pronounced heat-induced surface alterations in resin-based materials, whereas calcium silicate– and bioactive glass–based sealers largely preserved structural integrity. Elemental composition remained unchanged after heating. Conclusion: Warm obturation temperatures did not compromise chemical stability; however, thermal response was material dependent. Calcium silicate– and bioactive glass–based sealers demonstrated superior thermal and microstructural stability, supporting their suitability for heat-assisted obturation.