Flow and Filling of Cements Using Different Micro-computed Tomography Tests

Objectives: A new model for flow and filling capacity assessment of materials by volumetric measurements using computerized Microtomography was previously proposed. However, the influence of the size of the test models on the results was not analyzed. This study compared flow and volumetric filling of materials by using different sizes of models.
Methods: Glass plates were manufactured with a central cavity and four grooves for the horizontal and vertical directions. The diameter of the grooves suggested in the previous study 1 × 1 × 2 mm (length, width and height) was compared with the sizes: 1x1x1 mm and 1x2x1. Biodentine, IRM, and MTA were evaluated. Each material (n=6) was placed in the central cavity, and another glass plate and a metal weight were placed over the cement. The glass plate/material were scanned using micro-CT. The flow was calculated by linear measurement (mm) of the material in the grooves. Central cavity filling (CCF) was calculated in the central cavity (mm³). Lateral cavity filling (LCF) was measured up to 2 mm from the central cavity. Data were submitted to ANOVA and Tukey tests (α=0,05).
Results: Considering the materials, Biodentine presented the lowest flow, and better filling than IRM when evaluated in the 1x1x2 model (P<0,05). Considering the evaluated models, MTA presented the largest flow in the 1x1x2 model (P<0,05). All materials presented lower LCF when 1x1x2 model was used (P<0,05).
Conclusions: In conclusion, the linear flow of the materials can be affected by the size of the evaluated test models. The filling ability of the materials can also be influenced by the test models. Grooves with higher height and materials with higher flow have less filling capacity.