Objective To evaluate the apical sealing ability of iRoot SP root canal sealer in oval-root canal. Methods After root canals were instrumented by Mtwo, 28 premolars with oval-root canal were randomly divided into 2 groups, 14 teeth in each. The root canals were obturated with AH Plus (group A) and iRoot SP (group B) by modified continuous wave condensation technique. The apical leakage was evaluated by dye penetration method and transparent teeth technique. Results Mean depth of leakage was (0.92 ± 0.26) mm for group A and (0.84 ± 0.40) mm for group B. There was no significant difference between the two groups (t=0.506, P > 0.05). Conclusion The apical sealing ability of iRoot SP is equivalent to AH Plus in oval-root canal.

December 2019 witnessed the outbreak of COVID-19 in Wuhan and spread of the epidemic across the country. As a provincial designated hospital for critical patients, the First Affiliated Hospital of Zhejiang University responded rapidly since then by advocating the four-concentration principles, namely " concentrating patients, experts, resources and treatment" . In its rescue of critical patients, the hospital formulated comprehensive emergency plans, optimized hospital-wide resources, effectively arranged rescue spacing, established medical echelons, and implemented multi-disciplinary strategy. These efforts ensured efficient rescue and treatment, achieving a cure rate up to 98.7% of such patients, with no deaths.