bacterial entombment by intratubular mineralization following orthograde mineral trioxide aggregate obturation: a scanning electron microscopy study
The time domain entombment of bacteria by intratubular mineralization following orthograde canal obturation with mineral trioxide aggregate (MTA) was studied by scanning electron microscopy (SEM). Single-rooted human premolars (n560) were instrumented to an apical size #50/0.06 using ProFile and treated as follows: Group 1 (n510) was filled with phosphate buffered saline (PBS); Group 2 (n510) was incubated with Enterococcus faecalis for 3 weeks, and then filled with PBS; Group 3 (n520) was obturated orthograde with a paste of OrthoMTA (BioMTA, Seoul, Korea) and PBS; and Group 4 (n520) was incubated with E. faecalis for 3 weeks and then, obturated with OrthoMTA–PBS paste. Following their treatments, the coronal openings were sealed with PBS-soaked cotton and IRM and the roots were then stored in PBS for 1, 2, 4, 8 or 16 weeks. After each incubation period, the roots were split and their dentin/MTA interfaces examined in both longitudinal and horizontal directions by SEM. There appeared
Synthesis and hydration behavior of calcium zirconium aluminate (Ca7ZrAl6O18) cement
Calcium zirconium aluminate (Ca7ZrAl6O18) cements were prepared by solid state reaction and polymeric precursor methods, and their phase evolution, morphology, and hydration behavior were investigated. In poly-meric precursor method, a nearly single phase Ca7ZrAl6O18 was obtained at relatively lower temperature (1200 °C) whereas in solid state reaction, a small amount of CaZrO3 coexisted with Ca7ZrAl6O18 even at higher temperature (1400 °C). Unexpectedly, Ca7ZrAl6O18 synthesized by polymeric precursor process was the large-sized and rough-shaped powder. The planetary ball milling was employed to control the particle size and shape. The hydration behavior of Ca7ZrAl6O18 was similar to that of Ca3Al2O6 (C3A), but the hydration products were Ca3Al2O6·6H2O (C3AH6) and several intermediate products. Thus, Zr (or ZrO2) stabilized the intermediate hydration products of C3A.
Make Teeth Alive
5TH MTA(Make Teeth Alive) Clinical Case Report