Evaluation of reciprocating preparation, root canal filling, and the physicochemical and biological properties of filling and repair materials

Abstract

Constant evolution is observed in the development of techniques and kinematics of root canal preparation using Nickel-Titanium instruments, the root canal filling and repair materials and obturation techniques. The proposed studies aim to evaluate the preparation of oval root canals using the rotating or reciprocating kinematic, filling techniques, and physicochemical and biological properties of calcium silicate materials.Subproject 1 - Root canals of human mandibular extracted incisors with single oval root canal will be prepared by Nickel-Titanium instruments in rotating or reciprocating kinematic. The samples will be scanned with MicroCT SkyScan 1176 (Bruker-microCT, Belgium) and evaluated after preparation and after filling with different materials and techniques. Specimens will be also evaluated using histological analysis, and SEM .Subproject 2 - This study aims to develop cements based on tricalcium silicate or tricalcium aluminate associated with alternative radiopacifying agents. They will be compared to MTA Angelus, Biodentine and experimental cement Quick-Set. The following tests will be performed: setting time, flow, radiopacity, fluid uptake, pH, calcium and resistance to compression according to standard methods ISO 6876 and ISO 4049. Furthermore, cytotoxicity, and bioactivity will be examined in cell culture, chemical characterization using Energy Dispersive x-ray, scanning electron microscopy (SEM-EDX), x-ray Diffraction (XDR), infrared spectroscopy (FTIR). The antimicrobial activity will be assessed by direct contact test.Subproject 3 - The objective of this study is to evaluate the solubility, dimensional change, filling capacity, flow and porosity of root-end filling materials; and solubility, dimensional changes and porosity of sealers by using conventional tests, compared to proposed new methodologies using Micro-CT.Subproject 4 - The objective of the study is to evaluate the biological behavior and mineralized tissue formation of a tricalcium silicate experimental material with 20% zirconium oxide and MTA Plus. Human osteoblastic cells SAOS-2 (ATCC HTB-85) will be used for analysis of cellular cytotoxicity and bioactivity. Furthermore, the tissue response caused by the different materials will be evaluated in the subcutaneous tissue of rats. (AU)