The aim of this study is to evaluate the setting time, compressive strength, flow ability, film thickness, radiopacity, solubility, pH and calcium ion release of the root canal sealers MTA Fillapex, Sealapex, AH Plus and two experimental formulations of MTA based root canal sealers containing different radiopacifiers (zirconium oxide and niobium oxide in nano or micro particle size). Five specimens will be confectioned with standardized dimensions to analyze the setting time, compressive strength, flow ability, radiopacity, solubility, pH and calcium ion release. To evaluate the setting time of the root canal sealers, circular molds will be filled with the sealers and after 150 s Gilmore needle will be used to test the sealer surface. To test the compressive strength, cylinders of the root canal sealers will be confectioned and submitted to fracture in the EMIC DL universal machine after 24 h and 21 days. The flow ability test will follow the ISO 6876 varying the methodology measurement of the specimens and the film thickness will be measure through the difference in thickness of two glass slabs with the root canal sealers interposed between them. To evaluate the solubility of the sealers, the percentage loss in weight will be determined after 28 day. The pH will be measured using a digital pHmeter and the calcium ion release will be quantified after 1, 7, 14, 21 and 28 days of immersion of specimens in distilled water by atomic absorption spectrometry. To test radiopacity, the specimens will be radiographed and compared with an aluminum scale with different thickness. The adhesion of the root canal sealers to dentin will be determined by push-out test. Finally, the inorganic composition and formaldehyde release by the root canal sealers will be verified by x-Ray difractrometry and chromatography, respectively. The results will be submitted to statistical analysis using ANOVA test and Tukey post-hoc test with 95% confidence interval.
News published in Agência FAPESP Newsletter about the scholarship: