Objective : To investigate the effects of different root canal filling stop on quality of root canal filling and apical sealing in root canals obturated with GuttaFlow. Methods: 60 teeth were randomly divided into three groups, using different root canal filling stops to shape the root canals with MTwo (25/06) file. All root canals were obturated with Gutta Flow, and the overfilling of the root canals were recorded and evaluated by X-ray. And the apical microleakage of teeth was evaluated by transparent teeth technique. Results: The roots were prepared with MTwo (25/06) as master apical file, the overfilling rate of the root canals in root canal filling stop was higher as the distance from the apex was shorter, but there was no significant difference. The under-filling rate of the root canals in root canal filling stop was higher as the distance from the apex was longer. And the under-filled root canals in root canal filling stop 0.5 mm from the apex showed a statistically significant difference with 2 mm. The mean dyeing penetration length in 0.5 mm and 1 mm group was significantly shorter than 2 mm group. Conclusion A suitable root canal filling stop could improve the quality of root canal filling in root canals obturated with GuttaFlow.

Toxoplasma gondii is a worldwide parasite that can infect almost all kinds of mammals and cause fatal toxoplasmosis in immunocompromised patients. Apoptosis is one of the principal strategies of host cells to clear pathogens and maintain organismal homeostasis, but the mechanism of cell apoptosis induced by T. gondii remains obscure. To explore the apoptosis influenced by T. gondii, Vero cells infected or uninfected with the parasite were subjected to apoptosis detection and subsequent dual RNA sequencing (RNA-seq). Using high-throughput Illumina sequencing and bioinformatics analysis, we found that pro-apoptosis genes such as DNA damage-inducible transcript 3 (DDIT3), growth arrest and DNA damage-inducible α (GADD45A), caspase-3 (CASP3), and high-temperature requirement protease A2 (HtrA2) were upregulated, and anti-apoptosis genes such as poly(adenosine diphosphate (ADP)-ribose) polymerase family member 3 (PARP3), B-cell lymphoma 2 (Bcl-2), and baculoviral inhibitor of apoptosis protein (IAP) repeat containing 5 (BIRC5) were downregulated. Besides, tumor necrosis factor (TNF) receptor-associated factor 1 (TRAF1), TRAF2, TNF receptor superfamily member 10b (TNFRSF10b), disabled homolog 2 (DAB2)‍-interacting protein (DAB2IP), and inositol 1,4,5-trisphosphate receptor type 3 (ITPR3) were enriched in the upstream of TNF, TNF-related apoptosis-inducing ligand (TRAIL), and endoplasmic reticulum (ER) stress pathways, and TRAIL-receptor 2 (TRAIL-R2) was regarded as an important membrane receptor influenced by T. gondii that had not been previously considered. In conclusion, the T. gondii RH strain could promote and mediate apoptosis through multiple pathways mentioned above in Vero cells. Our findings improve the understanding of the T. gondii infection process through providing new insights into the related cellular apoptosis mechanisms.
Animals ; Apoptosis ; Chlorocebus aethiops ; Gene Expression Profiling ; Humans ; Mammals/genetics* ; Toxoplasma/genetics* ; Toxoplasmosis/pathology* ; Vero Cells ; ras GTPase-Activating Proteins/genetics*