During Arabidopsis root development, a radial pattern of tissues is extended by the meristem. These tissues form continuous layers and recent data suggest that tissue continuity is instrumental for constraining the direction of signaling in a process termed channeling. In the ground tissue, fate-determining signals originate from contiguous cells of the same layer, possibly due to specific symp...

The radial pattern of the plant root is determined by the action of two transcription factors, SHORT ROOT and SCARECROW, which are produced in different cell types. The SHORT ROOT protein has now been shown to move from cell to cell, regulating transcription of the downstream SCARECROW gene in the target cells.

The American Association of Endodontists defines root canal obturation as the complete, three-dimensional obturation of the root of canal system, as close as possible to the cemento-dentinal junction without overor underfilling. Moreover, obturation should be carried out using a minimal amount of biocompatible sealer and the obturated canal should demonstrate a radiographically dense filling ex...

introduction: the objective of this study was to compare the shaping ability of three rotary filing systems; constant taper k3 instruments, constant taper profile instruments and progressive taper protaper rotary instruments in clear resin blocks with simulated curved root canals. materials and methods: forty five resin blocks were divided into three groups. group a preparation was conducted wi...

internal inflammatory root resorption (iirr) is a rare condition of the root canal and if it is left untreated it may lead to destruction of the surrounding dental hard tissues. odontoclasts are responsible for this situation which can potentially perforate the root. many initiating factors have been mentioned for iirr, almost all causing chronic inflammation in the vital pulp. iirr is usually ...

microorganisms play a major role in initiation and perpetuation of pulpal and periapical diseases. therefore, elimination of the microorganisms present in the root canal system is the fundamental objective of endodontic treatment. the use of mechanical debridement, chemical irrigation or other antimicrobial protocols and intra-canal medicaments are critical to attain this goal. the aim of this ...