introduction: the aim of this study was to evaluate the retreatability of root canals obturated with gutta-percha (gp) and three different endodontic sealers [iroot sp (bioceramic sealer), mta fillapex (mta-based sealer) and ah-26 (epoxy resin-based sealer)] using the protaper universal retreatment (ptr) system. methods and materials: forty extracted single-rooted human teeth were prepared with...

Microorganisms play an important role in the weathering of silicate minerals in many subsurface environments, but an unanswered question is whether the mineral plays an important role in the microbial ecology. Silicate minerals often contain nutrients necessary for microbial growth, but whether the microbial community benefits from their release during weathering is unclear. In this study, we u...

Accurate control of groundwater pH is of critical importance for in situ biological treatment of chlorinated solvents. This study evaluated a novel approach for buffering subsurface pH that relies on the use of silicate minerals as a long-term source of alkalinity. A screening methodology based on thermodynamic considerations and numerical simulations was developed to rank silicate minerals acc...

Accurate control of groundwater pH is of critical importance for in situ biological treatment of chlorinated solvents. This study evaluated a novel approach for buffering subsurface pH that relies on the use of silicate minerals as a long-term source of alkalinity. A screening methodology based on thermodynamic considerations and numerical simulations was developed to rank silicate minerals acc...

A number of root-repair materials have been developed by various manufacturers, including Mineral Trioxide Aggregate (MTA) that has adequate biological and physical properties of a good root repair material [1,2]. MTA has been used for apexification, perforation repair, root resorption, and as a root-end filling material. The main ingredients of MTA are silicate oxide, tricalcium oxide, tricalc...

This experimental study examines the mineral/ melt partitioning of incompatible trace elements among high-Ca clinopyroxene, garnet, and hydrous silicate melt at upper mantle pressure and temperature conditions. Experiments were performed at pressures of 1.2 and 1.6 GPa and temperatures of 1,185 to 1,370 C. Experimentally produced silicate melts contain up to 6.3 wt% dissolved H2O, and are satur...

Mineral trioxide aggregate (MTA) was developed in early 1990s and has been successfully used for root perforation repair, root end filling, and one-visit apexification. MTA is composed mainly of tricalcium silicate and dicalcium silicate. When MTA is hydrated, calcium silicate hydrate (CSH) and calcium hydroxide is formed. Formed calcium hydroxide interacts with the phosphate ion in body fluid ...

Classical treatment of cell attachment by models of filtration or coulombic attraction assumes that attachment of cells to mineral surfaces would be controlled by factors such as response to predation, collision efficiency, or coulombic attraction between the charged groups at the mineral and cell surfaces. In the study reported here, the passive model of attachment was investigated using a nat...

This study was aimed to investigate the effect of mineral matter of Göynük oil shales (GOS) on pyrolysis and product evolution. Organic part was separated from mineral matter before pyrolysis in an isothermal pyrolysis reactor. In the demineralization step, carbonate, pyrite and silicates were removed from kerogen by using HCl, HNO3 and HF, respectively. Thereafter all samples were pyrolized in...

Laser-induced breakdown spectroscopy (LIBS) provides an alternative chemical analytical technique that obviates the issues of sample preparation and sample destruction common to most laboratory-based analytical methods. This contribution explores the capability of LIBS analysis to identify carbonate and silicate minerals rapidly and accurately. Fifty-two mineral samples (18 carbonates, 9 pyroxe...