Characterization, apatite-forming ability and influence of moisture conditions in the interaction with the root dentin of calcium silicate-based cements

• Grant number: 14/13257-2
• Support Opportunities: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): June 01, 2015
• Effective date (End): May 31, 2017
• Field of knowledge: Health Sciences - Dentistry - Endodontics
• Principal Investigator: Mario Tanomaru Filho
• Grantee: Raqueli Viapiana
• Host Institution: Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

Calcium silicate-based sealers are the new prospect of material to be used for root canal filling. This project is subdivided into three subprojects. Subproject 1 - aims to characterize with respect to radiopacity, flow ability, chemical composition and apatite-forming ability of three experimental root canal sealers based on calcium silicate (BioRoot, TCS-ZrP and TCS-Zr-S) in comparison to commercial disposed sealers (Apexit Plus and EndoSequence BC). Radiopacity and flow ability tests will follow ISO 6876:2012 specifications. Chemical characterization will be performed immediately after setting and also after aging in HBSS for 28 days in Hank's balanced salt solution (HBSS) to identify the hydrated rims and the apatite deposits, using scanning electron microscope with energy dispersive X-ray spectroscopy (SEM-EDS), X-ray diffraction (XDR) and infrared spectroscopy (FTIR). Subproject 2 - aims to evaluate the interaction of the same sealers tested on Subprojet 1 with the radicular dentin under different moisture conditions (dry or wet) regarding to dentin bond strength and by mapping sealer's penetration into dentin tubules using SEM-EDS and confocal laser scanning microscopy. Subproject 3 - the sealer with the best performance on subprojects 1 and 2 will be selected to be evaluated with respect to the sealing ability in comparison to AH Plus. Extracted human premolars pairs will be biomechanically prepared and splitted in two groups according to the sealer used to fill the root canals: (a) The calcium silicate-based root canal sealer with the best performance on subprojects 1 and 2; or (b) AH Plus. The sealing ability of the obturations will be evaluated by bacterial leakage assay and micro-computed tomography. Data will be submitted to statistical tests with 5% of significance.