A CBCT based digital analysis of shaping ability of Max Wire® alloy file in the treatment of large and curved root canals

Aim: To evaluate the limits of the shaping ability of MaxWire® alloy file in the treatment of pre-created large and curved root canals with different apical sizes by using cone-beam computed tomography (CBCT). Materials and methods: Forty-five permanent maxillary first molars with moderately curved palatal roots (20°-30°) were divided into three groups, and large root canals were created with apical diameter #35 (Group 1), #40 (Group 2) or #50 (Group 3) by using BioRace NiTi System. Then, they were reshaped with the MaxWire alloy file, XP-endo Shaper®. Canals were scanned before and after instrumentation by using the CBCT scanner. Canal transportation (CT), centering ratio (CR), % increased prepared area (PA), and % increased prepared outline (PO) at 2, 3, and 4 mm from the apex were calculated. Data were statistically analyzed at P < 0.05. Results: There was a significant difference in the mean increase in PO in all apical sizes and all three levels. At both 3 mm and 4 mm levels the maximum PA and PO were achieved in apical size 35, while at 2 mm level the maximum values were obtained in apical size 40. There was no statistically significant difference in CT and CR within groups at 2 mm distance from the apex. Conclusion: Max Wire alloy technology of this novel instrument makes it possible to clean and touch the dentin walls of large and curved root canals. Small FOV and small voxel size of CBCT could also be used in shaping ability studies in endodontics.

Effect of a novel bioceramic root canal sealer on the angiogenesis-enhancing potential of assorted human odontogenic stem cells compared with principal tricalcium silicate-based cements

Abstract Objective: This study evaluated the angiogenesis-enhancing potential of a tricalcium silicate-based mineral trioxide aggregate (ProRoot MTA), Biodentine, and a novel bioceramic root canal sealer (Well-Root ST) in human dental pulp stem cells (hDPSCs), human periodontal ligament stem cells (hPLSCs), and human tooth germ stem cells (hTGSCs). Methodology: Dulbecco's modified Eagle's medium was conditioned for 24 h by exposure to ProRoot MTA, Biodentine, or Well-Root ST specimens (prepared according to the manufacturers' instructions). The cells were cultured in these conditioned media and their viability was assessed with 3-(4,5-dimethyl-thiazol-2-yl)-5-(3-carboxy-methoxy-phenyl)-2-(4-sulfo-phenyl)-2H tetrazolium (MTS) on days 1, 3, 7, 10, and 14. Angiogenic growth factors [platelet-derived growth factor (PDGF), basic fibroblast growth factor (FGF-2), and vascular endothelial growth factor (VEGF)] were assayed by sandwich enzyme-linked immunosorbent assay (ELISA) on days 1, 7, and 14. Human umbilical vein endothelial cell (HUVEC) migration assays were used to evaluate the vascular effects of the tested materials at 6-8 h. Statistical analyses included Kruskal-Wallis, Mann-Whitney U, and Friedman and Wilcoxon signed rank tests. Results: None of tricalcium silicate-based materials were cytotoxic and all induced a similar release of angiogenic growth factors (PDGF, FGF-2, and VEGF) (p>0.05). The best cell viability was observed for hDPSCs (p<0.05) with all tricalcium silicate-based materials at day 14. Tube formation by HUVECs showed a significant increase with all tested materials (p<0.05). Conclusion: The tricalcium silicate-based materials showed potential for angiogenic stimulation of all stem cell types and significantly enhanced tube formation by HUVECs.