How do imaging protocols affect the assessment of root-end fillings?

Area of Science:

• Dental materials science
• Biomaterials engineering
• Radiology and imaging

Background:

• Accurate assessment of endodontic materials is crucial for treatment success.
• Micro-computed tomography (micro-CT) is a valuable tool for evaluating material-dentin interfaces and cement thickness.
• Understanding the influence of imaging parameters, like voxel size, is essential for reliable micro-CT analysis.

Purpose of the Study:

• To investigate the effect of micro-computed tomography (micro-CT) voxel size on the evaluation of voids and thickness of endodontic cements.
• To compare the performance of different voxel sizes (5, 10, and 20 µm) in analyzing mineral trioxide aggregate (MTA), Biodentine, and intermediate restorative material (IRM).

Main Methods:

• Maxillary premolars were filled with three endodontic cements (MTA, Biodentine, IRM) after root-end preparation.
• Samples were scanned using micro-CT at voxel sizes of 5, 10, and 20 µm.
• Cement/dentin interface voids and material thickness were analyzed, with statistical analysis including ANOVA, Tukey test, and Bland-Altman method.

Main Results:

• Increasing voxel size from 5 to 20 µm led to a significant increase in the measured thickness of all cements.
• At 5 µm, no significant differences in interface voids were found between materials.
• At 10 and 20 µm, Biodentine showed the lowest percentage of voids, while MTA and IRM showed decreased voids at 20 µm compared to smaller voxel sizes.

Conclusions:

• Voxel size significantly influences micro-CT assessments of endodontic cement thickness and interface voids.
• Larger voxel sizes (10 and 20 µm) generally resulted in increased thickness and decreased void detection.
• The choice of voxel size is critical for accurate and reproducible micro-CT analysis of endodontic materials.