The Effect of Intracanal Irrigants on Push out Bond Strength of CEM, Root MTA and Angelus MTA Cements to the Dentin Wall

Background and Objective: To reduce microbial contamination in cases such as perforation treatment, it is necessary to use irrigants after cement placement. The aim of the present study is to investigate the effect of intracanal irrigants on the push out bond strength of CEM, Root MTA and Angelus MTA cements to the dentin wall. Methods: In this laboratory research, 150 cross-section samples from the mid-root region of single canal teeth without caries with a thickness of 1 mm, which were randomly divided into 3 groups of 50 and filled with CEM cement, Root MTA or Angelus MTA, were examined. After the cements were set, the samples of each group were divided into 5 subgroups of 10; 4 subgroups were cleaned with sodium hypochlorite, EDTA, normal saline, 2% chlorhexidine for 30 minutes, and one subgroup was not cleaned as a control group. Then, the push out bond strength of cement with the dentin wall (MPa) and the failure pattern of the samples were evaluated. Findings: Different cleaning methods did not show any significant effect on the bond strength of CEM, Root MTA and Angelus MTA cements. In the cleaning method with saline, the bond strength of Angelus MTA (6.3±1.98) was higher than Root MTA (2.1±3.61) (p=0.004). In the cleaning method with 2% chlorhexidine, the bond strength of Angelus MTA cement (8.72±3.13) was higher compared to CEM (3.87±1.35) and Root MTA (4.66±1.76) (respectively p<0.001 and p=0.001). The most common type of failure in the Angelus MTA group was of the adhesive type, and in the CEM cement and Root MTA groups, it was of the mixed type. Conclusion: The results of the study showed that different cleaning methods have no effect on the push-out bond strength of the examined cements

GABAergic regulation of cerebellar NG2 cell development is altered in perinatal white matter injury.

Diffuse white matter injury (DWMI), a leading cause of neurodevelopmental disabilities in preterm infants, is characterized by reduced oligodendrocyte formation. NG2-expressing oligodendrocyte precursor cells (NG2 cells) are exposed to various extrinsic regulatory signals, including the neurotransmitter GABA. We investigated GABAergic signaling to cerebellar white matter NG2 cells in a mouse model of DWMI (chronic neonatal hypoxia). We found that hypoxia caused a loss of GABAA receptor-mediated synaptic input to NG2 cells, extensive proliferation of these cells and delayed oligodendrocyte maturation, leading to dysmyelination. Treatment of control mice with a GABAA receptor antagonist or deletion of the chloride-accumulating transporter NKCC1 mimicked the effects of hypoxia. Conversely, blockade of GABA catabolism or GABA uptake reduced NG2 cell numbers and increased the formation of mature oligodendrocytes both in control and hypoxic mice. Our results indicate that GABAergic signaling regulates NG2 cell differentiation and proliferation in vivo, and suggest that its perturbation is a key factor in DWMI

The Effect of Intracanal Irrigants on Push out Bond Strength of CEM, Root MTA and Angelus MTA Cements to the Dentin Wall

Background and Objective: To reduce microbial contamination in cases such as perforation treatment, it is necessary to use irrigants after cement placement. The aim of the present study is to investigate the effect of intracanal irrigants on the push out bond strength of CEM, Root MTA and Angelus MTA cements to the dentin wall. Methods: In this laboratory research, 150 cross-section samples from the mid-root region of single canal teeth without caries with a thickness of 1 mm, which were randomly divided into 3 groups of 50 and filled with CEM cement, Root MTA or Angelus MTA, were examined. After the cements were set, the samples of each group were divided into 5 subgroups of 10; 4 subgroups were cleaned with sodium hypochlorite, EDTA, normal saline, 2% chlorhexidine for 30 minutes, and one subgroup was not cleaned as a control group. Then, the push out bond strength of cement with the dentin wall (MPa) and the failure pattern of the samples were evaluated. Findings: Different cleaning methods did not show any significant effect on the bond strength of CEM, Root MTA and Angelus MTA cements. In the cleaning method with saline, the bond strength of Angelus MTA (6.3±1.98) was higher than Root MTA (2.1±3.61) (p=0.004). In the cleaning method with 2% chlorhexidine, the bond strength of Angelus MTA cement (8.72±3.13) was higher compared to CEM (3.87±1.35) and Root MTA (4.66±1.76) (respectively p<0.001 and p=0.001). The most common type of failure in the Angelus MTA group was of the adhesive type, and in the CEM cement and Root MTA groups, it was of the mixed type. Conclusion: The results of the study showed that different cleaning methods have no effect on the push-out bond strength of the examined cements