| Abstract [eng] |
The relevance of the problem and the aim of the work. Coronal microleakage is considered an important factor contributing to the failure of endodontic treatment due to reinfection of the root canal system. Although intraorifice barrier materials may reduce microleakage, their microstructural properties, particularly porosity, remain insufficiently investigated. The aim of this study was to evaluate the porosity of different intraorifice barrier materials used in endodontically treated teeth and their influence on composite porosity using micro-computed tomography analysis in vitro. Materials and methods. Thirty extracted single-rooted teeth were included and randomly divided into three groups (n = 10): zinc phosphate cement (Harvard cement), glass ionomer cement (Fuji IX GP), and no-barrier group. Root canals were chemomechanically prepared, obturated with hydraulic calcium silicate cement (BioRoot RCS) and gutta-percha, and a standardized 2 mm deep cavity below the canal orifice was prepared for barrier placement. In the first two groups, Harvard cement and Fuji IX GP barriers were placed, respectively, while in all groups the cavities were restored with a short fiber–reinforced flowable composite (EverX Flow). Porosity was evaluated using micro-computed tomography by assessing open, closed, and total porosity. Statistical analysis was performed using non–parametric Mann–Whitney U test with Bonferroni correction (p < 0.017) and Kruskal–Wallis test (p < 0.05). Results. Barrier material analysis revealed that Fuji IX GP showed significantly higher closed porosity compared to Harvard cement (p = 0.009), while no significant differences were found in open or total porosity. Composite analysis demonstrated no significant differences in closed porosity among groups (p = 0.897), whereas significant differences were observed in open (p = 0.008) and total porosity (p = 0.032). The lowest open porosity was found in the Harvard cement group and the highest in the no-barrier group. Pairwise comparisons showed a statistically significant difference only between the Harvard cement and no-barrier groups for open porosity. Conclusions. Harvard cement and Fuji IX GP barriers demonstrated a predominantly open porosity microstructure, while the porosity of EverX Flow composite may depend on the selected barrier material. The lowest composite porosity was observed with Harvard cement, while the highest was found without a barrier. Keywords: Endodontic treatment; Coronal microleakage; Intraorifice barrier; Porosity; Micro-computed tomography. |
