Amalgam, IRM, and a mineral trioxide aggregate were tested for repair of experimentally created root perforations. Fifty sound, extracted mandibular and maxillary molars were used in this study. A perforation was created on the mesial root surface at about a 45-degree angle to the long axis of each tooth. The tooth was then placed into a saline-soaked "Oasis" to simulate a clinical condition. A...

Root canal stripping is defined as an oblong, vertical perforation that appears especially in the middle section of curved root canals during endodontic treatments with nickel-titanium (Ni-Ti) instruments. Its occurrence may drastically affect the outcome of the treatment, transforming a common otherwise efficient endodontic procedure into a complication such as tooth extraction. In order to di...

STUDY DESIGN A prospective study of anterior transarticular screw (ATS) fixation patients. OBJECTIVE To develop a method to determine screw tip position through plain radiography after percutaneous ATS fixation to prevent occipitocervical joint (OCJ) violation. SUMMARY OF BACKGROUND DATA No studies using plain radiography to prevent OCJ violation during percutaneous ATS fixation have been p...

Objectives Root resorption is a dangerous side effect in orthodontics, and maxillary incisors are at the highest risk for root resorption. It is important to understand optimal force considerations for patients with altered root lengths.The purpose of this study was to investigate the effects of root length on stress distribution on roots by means of three dimensional fi...

BACKGROUND The juxtaposition of newly formed primordia in the root and shoot differs greatly, but their formation in both contexts depends on local accumulation of the signaling molecule auxin. Whether the spacing of lateral roots along the main root and the arrangement of leaf primordia at the plant apex are controlled by related underlying mechanisms has remained unclear. RESULTS Here, we s...

Morphological plasticity of root systems is critically important for plant survival because it allows plants to optimize their capacity to take up water and nutrients from the soil environment. Here we show that a signaling module composed of nitrogen (N)-responsive CLE (CLAVATA3/ESR-related) peptides and the CLAVATA1 (CLV1) leucine-rich repeat receptor-like kinase is expressed in the root vasc...

Branching by de novo formation of lateral roots along the primary root of Arabidopsis seedlings follows a complex longitudinal and transverse pattern. How this pattern is generated is presently under debate. The 'bending hypothesis' proposes that lateral root primordia are initiated by a local accumulation of auxin at the convex side of bends resulting from deflections through obstacles, gravit...

Determinate root growth is an important adaptation feature for seedling establishment in some Cactaceae. We show that seedlings of Pachycereus pringlei have primary roots with a stable determinate developmental program. How water stress affects determinate root growth and lateral root development has not been studied. Here we address this question. Root growth was analyzed in plants growing in ...

The plant-specific LATERAL ORGAN BOUNDARIES DOMAIN (LBD) genes are important regulators of growth and development. Here, a chrysanthemum class I LBD transcription factor gene, designated CmLBD1, was isolated and its function verified. CmLBD1 was transcribed in both the root and stem, but not in the leaf. The gene responded to auxin and was shown to participate in the process of adventitious roo...