Fluorescent microspheres were used as material markers to investigate the relative rates of cell surface expansion at the growing tips of Medicago truncatula root hairs. From the analysis of tip shape and microsphere movements, we propose three characteristic zones of expansion in growing root hairs. The center of the apical dome is an area of 1- to 2- microm diameter with relatively constant c...

Purpose: This study was conducted to evaluate the reliability of Schneider’s and Weine’s methods by comparing the difference of root canal curvatures measured by three examiners. Materials and Methods: Fifty-one selected premolars were measured by three trained graduates of endodontics respectively with Schneider’s and Weine’s methods. The results were analyzed with analysis of variance (ANOVA)...

This study evaluated the influence of irrigation tip, root canal curvature and final apical diameter on periapical debris and irrigant extrusion during root canal instrumentation. After being classified as mildly or moderately curved, the mesiobuccal root canals of 90 human molars were instrumented. The teeth were allocated into three groups according to the used needle type: a flat open-end ne...

Adenosine kinase (ADK) is a key enzyme that regulates intra- and extracellular levels of adenosine, thereby modulating methyltransferase reactions, production of polyamines and secondary compounds, and cell signaling in animals. Unfortunately, little is known about ADK's contribution to the regulation of plant growth and development. Here, we show that ADK is a modulator of root cap morphogenes...

introdouction: canal length measurement is essential for proper endodontic treatment. any error or miscalculation in working length determination, particularly in curved canals, can result in complications during or after root canal therapy. digital radiography has enabled accurate measurement of curved canal length. in this study, we evaluated the accuracy of calibration of a complementary met...

Aims This study assessed the effect of access design on angle, radius, and location of primary canal curvature in mesial roots of Type IV mandibular molars at different phases of root canal preparation. Methodology Twenty-four teeth were selected radiographically and via μCT and accessed with contracted (CEC; n = 12) or traditional endodontic cavity (TEC; n = 12) designs. Angle, radius, and loc...

PURPOSE The aim of this study was to evaluate, in vitro, the quality of calcium hydroxide [Ca(OH)(2)] paste filling (Ultracal, Ultradent) associated or not with Ca(OH)(2)-containing gutta-percha points (Calcium Hydroxide Plus Points, Roeko) in curved root canals. MATERIAL AND METHODS One hundred and twenty roots of extracted human teeth, randomly divided into three curvature ranges (mild - 0 ...

We consider the Dolbeault operator √ 2(∂ + ∂ *) of K 1 2 – the square root of the canon-ical line bundle which determines the spin structure of a compact Hermitian spin surface (M, g, J). We prove that all cohomology groups H 1 2)) vanish if the scalar curvature of g is non-negative and non-identically zero. Moreover, we estimate the first eigenvalue of the Dolbeault operator when the conformal...

introduction: the most important aims of root canal preparation are the removal of vital pulp tissue, remaining necrotic debris and infected dentin, eliminating the bulk of bacteria present in the root canal system. the aim of this study was to compare the cleaning efficacy of hand k-flexofiles and rotary race and k3 instruments in root canal preparation. materials and methods: a total of 60 si...

The quadratic form of the Dirac equation in a Riemann spacetime yields a gravitational gyromagnetic ratio κS = 2 for the interaction of a Dirac spinor with curvature. A gravitational gyromagnetic ratio κS = 1 is also found for the interaction of a vector field with curvature. It is shown that the Dirac equation in a curved background can be obtained as the square–root of the corresponding vecto...