Sealing ability of calcium-containing endodontic sealers TechBiosealer Endo, CRCS and Sealapex in teeth with open apices Aim To evaluate the sealing ability of three commercial Ca- containing endodontic sealers in teeth with artificial wide-open apices ex vivo. Methodology Thirty human single-rooted teeth were shaped with ProTaper instruments (Dentsply Maillefer, Switzerland) and then enlarged using a no. 4 Gates Glidden drill (Dentsply Maillefer) to obtain an apical root canal diameter of size 110. The canals were irrigated between each instrument with 0.5 mL of EDTA and 1 mL of NaOCl, and finally rinsed with deionized water. A tailored device was designed (Prati periapical chamber): a special silicone (Optosil) support was prepared for each root and 0.02 mL of HBSS (Hank’s Balanced Salt Solution) was added at the bottom of the support to simulate the presence of periapical fluid. The samples were randomly divided into three groups and filled with a hydraulic hydrophilic bioactive calcium-silicate sealer (TechBiosealer Endo, Italy), a calcium- hydroxide eucalyptol-&-eugenol-containing sealer (CRCS – Calciobi- otic Root Canal Sealer; Hygenic, USA) or a non-eugenol calcium- hydroxide polymeric root-canal sealer (Sealapex; Kerr, USA). Each sealer was prepared according to the manufacturers instruction and gently compacted with endodontic pluggers sizes 3 and 4 (LM-Dental, Finland) in the apical 5 mm. No back-filling was performed in order to leave a fluid reservoir for fluid-flow testing. All the samples were stored at 37°C in 10 mL of HBSS and the sealing ability was assessed after 24 h, 7 days, 1 and 3 months using a micro-infiltration measurer (Gandolfi digital fluid flow-meter) working at 1 psi hydraulic pressure. The data were statistically analyzed by two-way ANOVA (Student-Newman-Keuls test, significant differences at P < 0.05). Results TechBiosealer Endo maintained a stable seal from 24 h to 3 months showing values significantly lower than the other groups (P < 0.05). The fluid filtration values of TechBiosealer Endo (»0.045 lL min)1) and Sealapex (»0284 lL min)1) groups were significantly lower (P < 0.05) than CRCS group (»1.765 lL min)1). Conclusions The use of the hydraulic Ca-containing sealer TechBiosealers Endo provided the most stable seal compared to the other commercial Ca-containing sealers up to 3 months. The use of hydraulic hydrophilic bioactive sealers is recommendable for treatment of teeth with open apices.