Microtomographic Analysis of Resin Composite Core Material Porosity

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Advanced Imaging Techniques

Background:

• Resin composite core materials are crucial for dental restorations.
• Understanding their porosity is essential for predicting clinical performance and longevity.
• Nondestructive evaluation methods are preferred for material characterization.

Purpose of the Study:

• To nondestructively evaluate and compare the porosity of ten contemporary resin composite core materials.
• To quantify closed pore number, volume, and percentage using micro-computed tomography (microCT).
• To identify differences in porosity among various dual-cure, visible light-cure, and self-cure materials.

Main Methods:

• Ten resin composite core materials were fabricated according to manufacturer instructions.
• Specimens were analyzed using microCT at 5.3-µm resolution.
• Image analysis software was used to quantify porosity parameters, with statistical analysis performed using Kruskal-Wallis/Dunn tests.

Main Results:

• Significant differences in mean percent total porosity were observed across the ten materials.
• Ti-Core exhibited the highest porosity (2.2%), while Rebilda DC showed the lowest (0.02%).
• A pilot study indicated porosity can be introduced during the mixing of dual-cure resins via automix tips.

Conclusions:

• A broad spectrum of porosity exists among contemporary resin composite core materials.
• Further research is needed to evaluate more materials, automix tip performance, and unmixed material porosity.
• These findings highlight the importance of material selection and handling for minimizing porosity.