this case report presents conservative management of unset mineral trioxide aggregate (mta) after being placed as a root-end filling material following periapical surgery. periapical surgery was indicated for a maxillary lateral incisor of a 15-year-old male due to persistent exudate and a large periapical lesion. during surgery angelus mta was placed as root-end filling. the next session it wa...

Denisovite is a rare mineral occurring as aggregates of fibres typically 200-500 nm diameter. It was confirmed as a new mineral in 1984, but important facts about its chemical formula, lattice parameters, symmetry and structure have remained incompletely known since then. Recently obtained results from studies using microprobe analysis, X-ray powder diffraction (XRPD), electron crystallography,...

Ten chromite ores from ophiolite complexes in SE Iran were analyzed mineralogically by XRD, chemically by XRF, and mineral chemistry by EPMA. The identified paragenesis of silicate minerals of chromite ores with the X-ray diffraction is pronounced differently. It consists of secondary phases formed as serpentine, Cr-containing chlorite (kaemmererite), chromic garnet (uarovite) with preserved pa...

Mineral trioxide aggregate (MTA) is the most frequently used repair material in endodontics, but the long setting time and reduced mechanical strength in acidic environments are major shortcomings. In this study, a novel sol-gel-derived calcium silicate cement (sCSC) was developed using an initial Ca/Si molar ratio of 3, with the most effective mixing orders of reactants and optimal HNO3 cataly...

Hydrothermally grown crystals of beta-K3NdSi6O15, potassium neodymium silicate, have been studied by single-crystal X-ray methods. Under appropriate conditions, the compound crystallizes in space group Bb2(1)m and has lattice constants a = 14.370 (2), b = 15.518 (2) and c = 14.265 (2) A. There are 30 atom sites in the asymmetric unit of the basic structure. With eight formula units per unit cel...

Purely inorganic reactions of silica, metal carbonates, and metal hydroxides can produce self-organized complex structures that mimic the texture of biominerals, the morphology of primitive organisms, and that catalyze prebiotic reactions. To date, these fascinating structures have only been synthesized using model solutions. We report that mineral self-assembly can be also obtained from natura...