Is Micro X-ray Computer Tomography a Suitable Non-Destructive Method for the Characterisation of Dental Materials?

Area of Science:

• Materials Science
• Dental Materials
• Biomaterials

Background:

• Micro X-ray computed tomography (µXCT) is crucial for analyzing dental material microstructure.
• Understanding the impact of µXCT's X-ray radiation on material properties is essential for accurate analysis and material selection.

Purpose of the Study:

• To investigate the effects of X-ray radiation from µXCT on the mechanical performance and microstructure of various dental materials.
• To assess changes in flexural strength, porosity, and thermal properties after irradiation.

Main Methods:

• Standardized bending beams of dental materials were irradiated using an industrial tomograph.
• Flexural strength and porosity were quantified using 3D datasets before and after irradiation.
• Differential scanning calorimetry (DSC) was used to analyze thermal properties.

Main Results:

• Polycarbonate with acrylnitril-butadien-styrol (PC-ABS) showed a significant decrease in flexural strength after single µXCT irradiation.
• Resin-based composites (RBCs), poly(methyl methacrylate) (PMMA), and zinc phosphate cement (HAR) exhibited no significant change in flexural strength after single irradiation.
• DSC indicated potential microstructural changes in PMMA with increased radiation exposure (dose, duration, power).

Conclusions:

• High-dose X-ray radiation during µXCT can negatively impact the mechanical properties and microstructure of certain dental polymers, notably PC-ABS.
• While some dental materials like RBCs and cements are robust against single µXCT scans, polymers may be susceptible to cumulative or high-dose radiation effects.
• Further research is needed to establish safe radiation limits for dental materials analyzed with µXCT.