AIMS To devise an ex vivo model to test the efficacy of irrigation (static/dynamic) in removing a bio-molecular film from root canal walls. METHODOLOGY Forty human teeth with single straight canals were randomly allocated to two groups for static (n = 20) or dynamic (n = 20) irrigation. The root canals were prepared to different apical sizes (20, 40) and tapers (0.04, 0.08). The teeth were sp...

The unicellular green alga Acetabularia acetabulum has proven itself to be a superior model for studies of morphogenesis because of its large size and distinctive polar morphology. The giant cell forms an elongated tube (a stalk of up to 60 mm in length), which at its apical pole makes whorls of hairs, followed by one whorl of gametophores in the shape of a cap. At its basal pole, the cell exte...

OBJECTIVE The objective of this study was to compare 2 preparation techniques performed under simulated clinical conditions with extended apical enlargement following determination of the optimal apical preparation size (APS). STUDY DESIGN After preflaring 240 root canals, APS was evaluated as outlined in Part I. The apical portion was shaped to APS either with rotary NiTi Lightspeed instrume...

The asymmetric division of Drosophila neuroblasts involves the basal localization of cell fate determinants and the generation of an asymmetric, apicobasally oriented mitotic spindle that leads to the formation of two daughter cells of unequal size. These features are thought to be controlled by an apically localized protein complex comprising of two signaling pathways: Bazooka/Drosophila atypi...

The cleaning capacity of Hero 642 nickel-titanium files, complemented by the Hero Apical instruments in flattened roots, was determined by histological analysis, considering the area of action of the instruments on the coronal walls and the presence of remaining debris. Twenty-four single-canal, human mandibular incisors were divided into three groups and prepared as follows: GI, instrumented w...

We have previously shown that a thin ( approximately 1 microm) layer of intermediate filaments located beneath the apical membrane of a variety of simple epithelial cells participates in the organization of apical microfilaments and microtubules. Here, I confirmed the apical distribution of gamma-tubulin-containing structures (potential microtubule-organizing centers) in CACO-2 cells and demons...

Understanding the complexity of the root canal system and the aim to provide successful endodontic treatment has led to the development of newer techniques, instruments, and materials. These recent developments have greatly enhanced the clinician’s ability to achieve biologically-based objectives of root canal treatment. In order to achieve these objectives, it is imperative to accurately deter...

Introduction: Apical seal in blood or dry root canal is a problem in endodontic treatment. Failure of apical seal causes inflammatory reaction and failure root canal treatment. Because of the sealer properties, root canal should be dry for obturation. But hydrophilic sealers can adhere to root canal walls nowadays and this problem is still controversial. This study aimed at determining the apic...

We have produced a spectrum of limb defects in developing mouse embryos by exposing the mother to smoke from cigarettes with different nicotine concentrations, ethanol, and a combination of ethanol and cigarette smoke. The critical time of exposure was determined to be during day 10 of gestation (vaginal plug=day 0). This time is prior to the critical events which occur between the apical e...

BACKGROUND The interpretation of myocardial perfusion scintigraphy (MPS) largely relies on visual assessment by the physician of the localization and extent of a perfusion defect. The aim of this study was to introduce the concept of the perfusion vector as a new objective quantitative method for further assisting the visual interpretation and to test the concept using simulated MPS images as w...